Lung Carcinoid Tumor What is cancer?
The body is made up of hundreds of millions of living cells. Normal body cells grow, divide, and die in an orderly fashion. During the early years of a person's life, normal cells divide faster to allow the person to grow. After the person becomes an adult, most cells divide only to replace worn-out or dying cells or to repair injuries.
Cancer begins when cells in a part of the body start to grow out of control. There are many kinds of cancer, but they all start because of out-of-control growth of abnormal cells.
Cancer cell growth is different from normal cell growth. Instead of dying, cancer cells continue to grow and form new, abnormal cells. Cancer cells can also invade (grow into) other tissues, something that normal cells cannot do. Growing out of control and invading other tissues are what makes a cell a cancer cell.
Cells become cancer cells because of damage to DNA. DNA is in every cell and directs all its actions. In a normal cell, when DNA gets damaged the cell either repairs the damage or the cell dies. In cancer cells, the damaged DNA is not repaired, but the cell doesn't die like it should. Instead, this cell goes on making new cells that the body does not need. These new cells will all have the same damaged DNA as the first cell does.
People can inherit damaged DNA, but most DNA damage is caused by mistakes that happen while the normal cell is reproducing or by something in our environment. Sometimes the cause of the DNA damage is something obvious, like cigarette smoking. But often no clear cause is found.
In most cases the cancer cells form a tumor. Some cancers, like leukemia, rarely form tumors. Instead, these cancer cells involve the blood and blood-forming organs and circulate through other tissues where they grow.
Cancer cells often travel to other parts of the body, where they begin to grow and form new tumors that replace normal tissue. This process is called metastasis. It happens when the cancer cells get into the bloodstream or lymph vessels of our body.
No matter where a cancer may spread, it is always named for the place where it started. For example, breast cancer that has spread to the liver is still called breast cancer, not liver cancer. Likewise, prostate cancer that has spread to the bone is metastatic prostate cancer, not bone cancer.
Different types of cancer can behave very differently. For example, lung cancer and breast cancer are very different diseases. They grow at different rates and respond to different treatments. That is why people with cancer need treatment that is aimed at their particular kind of cancer.
Not all tumors are cancerous. Tumors that aren't cancer are called benign. Benign tumors can cause problems -- they can grow very large and press on healthy organs and tissues. But they cannot grow into (invade) other tissues. Because they can't invade, they also can't spread to other parts of the body (metastasize). These tumors are almost never life threatening.
What are lung carcinoid tumors?
Lung carcinoid tumors are an uncommon type of tumor that starts in the lungs. They tend to grow slower than other types of lung cancers. They are made up of special kinds of cells called neuroendocrine cells.
To understand lung carcinoid tumors, it helps to know something about the normal structure and function of the lungs, as well as the neuroendocrine system.
The lungs are 2 sponge-like organs in your chest cavity. Your right lung has 3 sections, called lobes. The left lung has 2 lobes. It is smaller because the heart takes up more room on that side of the body. The lungs bring air in and out, taking in oxygen and getting rid of carbon dioxide gas, a waste product of the body.
When you breathe in, air enters through your mouth and nose and goes into your lungs through the trachea (windpipe). The trachea divides into tubes called the bronchi (singular, bronchus), which divide into smaller branches called the bronchioles. At the end of the bronchioles are tiny air sacs known as alveoli.
A thin lining called the pleura surrounds the lungs. The pleura protects your lungs and helps them slide back and forth as they expand and contract during breathing. The chest cavity is called the pleural cavity.
Carcinoid tumors start from cells of the diffuse neuroendocrine system. This system is made up of cells that are like nerve cells in certain ways and like hormone-making endocrine cells in other ways. These cells do not form an actual organ like the adrenal or thyroid glands. Instead, they are scattered throughout the body in organs like the lungs, stomach, and intestines.
Neuroendocrine cells make hormones like adrenaline and adrenaline-like substances. In the lungs, this may help control air flow and blood flow and may help control the growth of other types of lung cells. Neuroendocrine cells may detect decreased oxygen or increased carbon dioxide in the air we breathe and then release chemical messages to help the lungs adjust to these changes. People who live at higher altitudes have more lung neuroendocrine cells, probably because there is less oxygen in the air they breathe.
Like most cells in your body, lung neuroendocrine cells sometimes go through certain changes that cause them to grow too much and form tumors. These are known as neuroendocrine tumors or neuroendocrine cancers. Neuroendocrine tumors can develop anywhere in the body. Neuroendocrine tumors that begin in the digestive tract, another common site for these tumors, are discussed in a separate American Cancer Society document, Gastrointestinal Carcinoid Tumors. This document discusses only neuroendocrine tumors that start in the lungs.
There are 4 types of neuroendocrine lung tumors:
Small cell lung cancer
Small cell lung cancer (SCLC) is one of the fastest growing and spreading of all cancers. It is discussed in a separate American Cancer Society document, Lung Cancer (Small Cell).
Large cell neuroendocrine carcinoma
Large cell neuroendocrine carcinoma (LCNEC) is a rare cancer that, except for the size of the cells forming the cancer, is very similar to SCLC in its prognosis (outlook) and in how patients are treated.
Typical and atypical carcinoid tumors
The other 2 types of lung neuroendocrine tumors are carcinoids. The rest of this document will only cover these 2 types of tumors.
Carcinoid tumors start from cells of the diffuse neuroendocrine system. Typical and atypical carcinoid tumors look different under the microscope.
• Typical carcinoids grow slowly and only rarely spread beyond the lungs. About 9
out of 10 lung carcinoids are typical carcinoids.
• Atypical carcinoids grow a little faster and are somewhat more likely to spread to
other organs. Seen under a microscope, they have more cells in the process of dividing and look more like a fast-growing tumor. They are much less common than typical carcinoids.
Carcinoids are sometimes also classified by where they form in the lung.
• Central carcinoids form in the walls of large airways (bronchi) near the center of the
lungs. Most lung carcinoid tumors are central carcinoids, and nearly all of these are also typical carcinoids.
• Peripheral carcinoids develop in the narrower airways toward the edges of the
lungs. Most peripheral carcinoids are also typical carcinoids.
This distinction is important because the tumor's location affects which symptoms a patient may have (see the section "How are lung carcinoid tumors diagnosed?”) and may also affect how the tumor is treated.
What are the key statistics about lung carcinoid tumors?
About 1% to 2% of all lung cancers are carcinoids. This means there are about 4,500 newly diagnosed lung carcinoid tumors in the United States each year.
Carcinoid tumors are actually more common in the digestive tract than in the lungs. Only about 3 out of 10 carcinoid tumors start in the lungs.
Lung carcinoids are more common in whites than in African Americans, Asian Americans, or Hispanics/Latinos. They are also more common in women.
In contrast with other types of lung cancer, carcinoids tend to be diagnosed in people who are slightly younger. The average age at diagnosis is around 60 years.
Information on survival rates for lung carcinoids can be found in the section, "How are lung carcinoid tumors staged?"
What are the risk factors for lung carcinoid tumors?
A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors. For example, strong sunlight is a risk factor for skin cancer, and smoking is a risk factor for cancers of the lung, larynx (voice box), mouth, throat, esophagus, kidneys, bladder, and several other organs.
But risk factors don't tell us everything. Having a known risk factor, or even several risk factors, does not mean that you will get the disease. And many people who get the disease may not have had any known risk factors.
Not much is known about why lung carcinoid tumors develop in some people but not in others.
Typical lung carcinoid tumors do not seem to be linked with smoking or with any known chemicals in the environment or workplace. But some studies have found that atypical lung carcinoids may be more common in people who smoke.
Carcinoids occur more often in women than in men. The reasons for this are not known.
Lung carcinoids are more common in whites than in African Americans, Asian Americans, or Hispanics/Latinos.
These tumors are usually found in people about 60 years old, which is slightly younger than the average age for other types of lung cancer. But carcinoids can occur in people of almost any age. Although it is rare, lung carcinoid tumors are sometimes even found in children.
People with multiple endocrine neoplasia type 1 (MEN1, an inherited syndrome) are at high risk for tumors in the pancreas and in the pituitary and parathyroid glands. They also seem to be at increased risk for lung carcinoid tumors.
Most people with lung carcinoid tumors do not have a family history of this type of cancer, but a tendency to develop lung carcinoid tumors can be inherited. In rare cases, several family members have been diagnosed with this cancer. But because this cancer is so uncommon, the risk is still low.
Do we know what causes lung carcinoid tumors?
Very little is known about what causes lung carcinoid tumors. Researchers have learned a lot about how certain risk factors like cancer-causing chemicals or radiation can cause changes in lung cells that lead to carcinomas, the more common type of lung cancer. But these factors are not thought to play a large role in the development of lung carcinoid tumors.
Carcinoid tumors probably develop from tiny clusters of neuroendocrine cells in the lung airways called carcinoid tumorlets. Tumorlets are sometimes found unexpectedly in lung biopsies done to treat or diagnose other conditions. Under the microscope, tumorlets resemble carcinoid tumors, except that they are much smaller -- less than 5 mm (¼ inch) across.
Most tumorlets never grow any bigger, but some may eventually become carcinoid tumors. Researchers still do not understand how carcinoid tumorlets develop from lung neuroendocrine cells or why tumorlets sometimes grow to become carcinoid tumors.
Can lung carcinoid tumors be prevented?
Because we do not yet know what causes most lung carcinoid tumors, it is not possible to know how to prevent them. Smoking has been linked with an increased risk of atypical carcinoids, so quitting (or not starting) might reduce a person's risk.
Can lung carcinoid tumors be found early?
Lung carcinoid tumors are not common, and there are no widely recommended screening tests for these tumors in most people. (Screening is testing for cancer in people without any symptoms.) People with multiple endocrine neoplasia type 1 (MEN1) are at increased risk for these tumors, and some doctors recommend they have computed tomography (CT) scans of the chest every 3 years starting when they are age 20.
Because carcinoid tumors usually grow and spread slowly, most are found at an early or localized stage. Many patients with peripheral carcinoid tumors or with small central carcinoid tumors have no symptoms. Carcinoids that do not cause symptoms often are found on a chest x-ray done during a routine exam or when looking into unrelated medical problems, such as some heart diseases.
How are lung carcinoid tumors diagnosed?
Certain signs and symptoms might suggest that a person may have a lung carcinoid tumor, but tests are needed to confirm the diagnosis.
About 2 out of 3 people with carcinoid tumors will have signs or symptoms that will lead to the diagnosis of the disease. But because carcinoids tend to grow slowly, they may not cause symptoms for several years in some people, or they may be found by medical tests done for other reasons.
Central carcinoid tumors
These tumors start in the large bronchial tubes leading into the lung. People with these tumors may have a cough or cough up bloody sputum, or they may have wheezing symptoms like asthma. Other possible symptoms include shortness of breath and chest pain, especially when taking deep breaths. Large carcinoids can cause partial or complete blockage of a large air passage, leading to a lung infection called post-obstructive pneumonia. Sometimes a doctor may suspect a tumor only after treatment with antibiotics fails to cure the pneumonia.
Peripheral carcinoids
These tumors start in the smaller airways toward the outer edges of the lungs. They rarely cause any symptoms unless there are so many of them they interfere with breathing. Usually they are found as a spot on a chest x-ray taken for an unrelated problem.
Symptoms caused by hormones produced by the tumor
Some carcinoid tumors can produce hormone-like substances that are released into the bloodstream. Lung carcinoids do this far less often than gastrointestinal carcinoid tumors.
Carcinoid syndrome: Rarely, lung carcinoid tumors release enough hormone-like substances into the bloodstream to cause symptoms. This results in the carcinoid syndrome. Symptoms include facial flushing (redness and warm feeling), severe diarrhea, wheezing, and fast heartbeat. Many patients find that stress, heavy exercise, and drinking alcohol may make these symptoms worse. Over a long time, these hormone-like substances can damage heart valves, causing shortness of breath, weakness, and a heart murmur (an abnormal heart sound). Cushing syndrome: In rare cases, lung carcinoid tumors may produce ACTH. This substance causes the adrenal glands to make too much cortisol and other hormones. This can cause weight gain, weakness, high blood sugar (or even diabetes), and increased body and facial hair.
Although the symptoms and signs above may be caused by lung carcinoid tumors, they can also be caused by other conditions. Still, if you have any of these problems, it's important to see your doctor right away so the cause can be found and treated, if needed.
If you have any signs or symptoms that suggest you might have a lung carcinoid tumor, your doctor will want to take a complete medical history, including your family history, to check for symptoms and possible risk factors. You will also be asked about your general health.
A physical exam provides information about your general health, possible signs of lung carcinoid tumor, and other health problems. During your physical exam, your doctor will pay close attention to your chest and lungs.
If symptoms and/or the results of the physical exam suggest a lung carcinoid tumor might be present, more involved tests probably will be done. These might include imaging tests, lab tests, and other procedures.
Imaging tests use x-rays, radioactive particles, or other means to create pictures of the inside of your body. Imaging tests may be done for a number of reasons, including to
help find a suspicious area that might be cancerous, to learn how far cancer may have spread, and to help determine if treatment has been effective.
Chest x-ray
A chest x-ray may be the first imaging test a doctor orders if he or she suspects a lung problem. It might be able to show if there is a tumor in the lung. However, some carcinoids that are small or are in places where they are covered by other organs in the chest may not show up on a chest x-ray. If your doctor is still suspicious or if a vague abnormality appears on the chest x-ray, a CT scan may be ordered.
Computed tomography (CT) scan
The CT scan is an x-ray procedure that produces detailed cross-sectional images of your body. Instead of taking one picture, like a regular x-ray, a CT scanner takes many pictures as it rotates around you while you are lying on a narrow platform. A computer then combines these into images of slices of the part of your body that is being studied. Before the scan, you may be asked to drink a contrast solution and/or get an intravenous (IV) injection of a contrast dye that helps better outline abnormal areas in the body.
You may need an IV line through which the contrast dye is injected. The injection can cause some flushing (redness and warm feeling). Some people are allergic and get hives or, rarely, more serious reactions like trouble breathing and low blood pressure. Be sure to tell the doctor if you have ever had a reaction to any contrast material used for x-rays.
You need to lie still on a platform while the scan is being done. During the test, the platform moves in and out of the scanner, a ring-shaped machine that completely surrounds it. You might feel a bit confined by the ring you have to lie in while the pictures are being taken.
• CT scans of the chest can spot very small lung tumors and help determine the exact
• CT scans can be helpful in staging a cancer (determining the extent of its spread). For
example, CT scans of the abdomen can show if the cancer has spread to the liver or other organs. This can help to determine if surgery is a good treatment option.
• CT scans can also be used to guide a biopsy needle precisely into a suspected tumor
or metastasis. For this procedure, called a CT-guided needle biopsy, the patient remains on the CT scanning table, while a radiologist advances a biopsy needle through the skin and toward the location of the mass. CT scans are repeated until the needle is within the mass. A biopsy sample is then removed and looked at under a microscope.
Radionuclide scans
Scans using small amounts of radioactivity and special cameras may be helpful in looking for carcinoid tumors. They can help determine the extent of the tumor, as well as help locate it if doctors aren't sure where it is in the body.
Somatostatin receptor scintigraphy: The most commonly used scan is somatostatin receptor scintigraphy (SRS), also known as the OctreoScan. It uses octreotide bound to radioactive indium-111. Octreotide is a hormone-like substance that attaches to carcinoid cells. A small amount of this substance is injected into a vein. It travels through the blood and is attracted to carcinoid tumors. About 4 hours after the injection, a special camera can be used to show where the radioactivity has collected in the body. More scans may be done in the following few days as well. I-131 MIBG: This test is used less often. It uses a chemical called MIBG to which radioactive iodine (I-131) is attached. This substance is injected into a vein, and the body is scanned several hours or days later with a special camera to look for areas that picked up the radioactivity. These would most likely be carcinoid tumors, although other kinds of neuroendocrine tumors will also pick up this chemical. Positron emission tomography (PET): A PET scan is another imaging test that uses low levels of radioactivity to look for tumors. For most diseases, PET scans use a form of radiolabeled glucose (sugar) to find tumors. This type of PET scan is not very useful in finding carcinoid tumors. PET scanning for carcinoid tumors usually uses a radioactive form of 5-hydroxytryptophan, a chemical that is taken up and used by carcinoid cells. A special camera can detect the radioactivity. The usefulness of this test for lung carcinoid tumors is still being studied. This special type of PET scan is not available in every hospital.
Even if an imaging test such as a chest x-ray or CT scan finds a mass, it is often hard for doctors to tell if the mass is a carcinoid tumor, another type of lung cancer, or an area of infection. In many cases, the only way to know for sure is to remove cells from the tumor and look at them under a microscope. This procedure is called a biopsy. There are several ways to take a sample from a lung tumor.
Bronchoscopic biopsy
This approach is used to view and sample tumors of large airways, such as central carcinoids. The doctor passes a long, thin, flexible, fiber-optic tube called a bronchoscope down the throat, through the windpipe, and into the lungs to look at the lining of the lung's main airways. You will be sedated for this. If a tumor is found, the doctor can take a small sample of the tumor through the tube. The doctor can also take a brushing sample through the bronchoscope by wiping a tiny brush over the surface of the tumor. Brushing samples are sometimes a helpful addition to the bronchial biopsy, but they are not as helpful in diagnosing carcinoids as they are with lung carcinomas.
An advantage of this type of biopsy is that no surgical incision or hospital stay is needed, and you are ready to return home within hours. A disadvantage is that this type of biopsy may not always be able to remove enough of a sample to be certain the tumor is a carcinoid. But with recent advances in the lab testing of lung tumors, doctors can usually make an accurate diagnosis even with very small samples.
Bleeding from a carcinoid tumor after a biopsy is rare but it can be a serious problem. If bleeding becomes a problem, doctors can inject drugs through the bronchoscope into the tumor to narrow its blood vessels, or they can seal off the bleeding vessels with a laser aimed through the bronchoscope.
Needle biopsies
Tumors that are not near the large airways are often sampled by needle biopsy. A long, hollow needle is passed through the skin in the chest between the ribs and into the lung. CT scan images are used to guide the needle into the tumor so that a small sample can be removed and looked at under the microscope. This procedure is also done without a surgical incision or overnight hospital stay.
A possible complication of this approach is the buildup of air between the lung and the chest wall, which is known as a pneumothorax. In some cases this can lead to the collapse of part of a lung, causing shortness of breath. If this happens, it can be treated by temporarily placing a suction tube through the skin and into the chest, which will re-expand the lung.
Surgical biopsies
In some cases, neither a bronchoscopic biopsy nor a needle biopsy will remove enough tissue to identify the type of tumor, and your doctor may need to do surgery to get a biopsy sample. Different types of operations may be used.
Thoracotomy: For a thoracotomy, the surgeon makes an incision in the chest wall between the ribs to get to the lungs and to the space between the lungs and the chest wall. In some cases if the doctor strongly suspects a carcinoid or some other type of lung cancer, they may do a thoracotomy and remove the entire tumor without first doing a biopsy. Thoracoscopy: This procedure is less invasive than a thoracotomy. It is also used to look at the space between the lungs and the chest wall. Most often it is done in the operating room while you are under general anesthesia (in a deep sleep). The doctor inserts a thin, lighted scope with a small video camera on the end through a small cut made in the chest wall to look at the space between the lungs and the chest wall. (Sometimes more than one cut is made.) Using this scope, the doctor can see potential areas of cancer and remove small pieces of tissue to look at under the microscope. Thoracoscopy can also be used to sample lymph nodes and fluid and find out whether a tumor is growing into nearby tissues or organs. Mediastinoscopy: If imaging tests such as a CT scan suggest that the cancer may have spread to the lymph nodes between the lungs, the doctor may do a procedure called a mediastinoscopy. This is done in an operating room while you are under general anesthesia (in a deep sleep). A small cut is made in the front of the neck above the breastbone (sternum) and a thin, hollow, lighted tube is inserted behind the sternum. Special instruments can be passed through this tube to take tissue samples from the lymph nodes along the windpipe and the major bronchial tube areas.
Because carcinoid tumors can secrete hormone-like chemicals into the blood, the tumor can sometimes be detected by simple blood or urine tests. This is especially true if you have symptoms of the carcinoid syndrome, which is caused by excessive levels of these substances in the blood.
Serotonin is a substance made by some carcinoid tumors, and probably causes some of the symptoms. It is broken down by the body into 5-hydroxyindoleacetic acid (5-HIAA), which is released into the urine. A commonly used test to look for carcinoid syndrome measures the levels of 5-HIAA in a urine sample collected over 24 hours. Measuring the serotonin levels in the blood or urine may also give useful information. These tests can help diagnose some carcinoid tumors, but they are not always accurate. Some other medical conditions, as well as foods and medicines, can affect the results, and some carcinoid tumors may not release enough of these substances to give a positive test result.
Other tests commonly used to look for carcinoids can include blood tests for chromogranin A (CgA), neuron-specific enolase (NSE), cortisol, and substance P. Depending on where the tumor might be located and on the patient's symptoms, doctors may do other blood tests as well.
Abnormal lab test results are not as likely to be seen with lung carcinoid tumors as they are with carcinoid tumors that start elsewhere in the body.
Pulmonary function tests (PFTs) are often done after a lung carcinoid diagnosis to see how well your lungs are working. This is especially important if surgery is an option in treating the cancer. Because surgery will remove part or all of the lung , it's important to know how well the lungs are working beforehand. These tests can give the surgeon an idea of whether surgery is a good option, and if so, how much lung can safely be removed.
There are a few different types of PFTs, but they all basically have you breathe in and out through a tube that is connected to different machines.
How are lung carcinoid tumors staged?
Staging is a process of finding out how far a cancer has spread. Your treatment and prognosis (the outlook for chances of survival) depend, to a large extent, on the cancer's stage.
Staging is based on the results of the physical exam, biopsies, and imaging tests (CT scan, PET scan, etc.), which are described in the section, "How are lung carcinoid tumors diagnosed?"
The staging system for lung carcinoid tumors is the same one used to stage non-small cell lung cancer -- the American Joint Committee on Cancer (AJCC) TNM staging system. The TNM system describes 3 key pieces of information:
• T indicates the size of the main (primary) tumor and whether it has grown into
• N describes how much the cancer has spread to nearby (regional) lymph nodes.
Lymph nodes are small bean-shaped collections of immune system cells that are important in fighting infections.
• M indicates whether the cancer has spread (metastasized) to other organs of the
body. (The most common site is the liver.)
Numbers or letters appear after T, N, and M to provide more details about each of these factors. The numbers 0 through 4 indicate increasing severity. The letter X means cannot be assessed because the information is not available. TX: The main (primary) tumor can't be assessed, or cancer cells were seen on sputum cytology but no tumor can be found. T0: There is no evidence of a primary tumor. Tis: The cancer is found only in the top layers of cells lining the air passages. It has not invaded into deeper lung tissues. This stage is also known as carcinoma in situ. T1: The tumor is no larger than 3 cm (slightly less than 1¼ inches) across, has not reached the membranes that surround the lungs (visceral pleura), and does not affect the main branches of the bronchi.
• T1a: A T1 tumor that is 2 cm (about 4/5 of an inch) or less across.
• T1b: A T1 tumor that is larger than 2 cm but not larger than 3 cm across. T2: The tumor has 1 or more of the following features:
• It is between 3 cm and 7 cm across (larger than 3 cm but not larger than 7 cm). If the
tumor is 5 cm or less across (but still larger than 3 cm), it is called T2a. If the tumor is larger than 5 cm across (but not larger than 7 cm), it is called T2b.
• It involves a main bronchus, but is not closer than 2 cm (about ¾ inch) to the carina
(the point where the windpipe splits into the left and right main bronchi).
• It has grown into the membranes that surround the lungs (visceral pleura).
• The tumor partially clogs the airways, but this has not caused the entire lung to
T3: The tumor has 1 or more of the following features:
• It has grown into the chest wall, the breathing muscle that separates the chest from the
abdomen (diaphragm), the membranes surrounding the space between the two lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• It invades a main bronchus and is closer than 2 cm (about ¾ inch) to the carina, but it
• It has grown into the airways enough to cause an entire lung to collapse or to cause
• Two or more separate tumor nodules are present in the same lobe of a lung
T4: The cancer has 1 or more of the following features:
• A tumor of any size has grown into the space behind the chest bone and in front of the
heart (mediastinum), the heart, the large blood vessels near the heart (such as the aorta), the windpipe, the esophagus (tube connecting the throat to the stomach), the backbone, or the carina.
• Two or more separate tumor nodules are present in different lobes of the same lung.
NX: Nearby lymph nodes cannot be assessed. N0: There is no spread to nearby lymph nodes. N1: The cancer has spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). Affected lymph nodes are on the same side as the primary tumor(s). N2: The cancer has spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space behind the breastbone and in front of the heart (mediastinum). Affected lymph nodes are on the same side as the primary tumor. N3: The cancer has spread to lymph nodes near the collarbone on either side, and/or spread to hilar or mediastinal lymph nodes on the side opposite the primary tumor. M0: No spread to distant organs or areas. This includes other lobes of the lungs, lymph nodes further away than those mentioned in the N stages above, and other organs or tissues such as the liver, bones, or brain. M1: The cancer has spread to 1 or more distant sites. This can be to another lobe of the lung, to distant lymph nodes, or to other organs. M1a: Any of the following:
• The cancer has spread to the other lung.
• Cancer cells are found in the fluid around the lung (called a malignant pleural
• Cancer cells are found in the fluid around the heart (called a malignant pericardial M1b: The cancer has spread to distant organs or lymph nodes.
Stage grouping for lung cancer and lung carcinoid
Once the T, N, and M categories have been assigned, this information is combined (stage grouping) to assign an overall stage of 0, I, II, III, or IV. Some stages are subdivided into A and B. The stages identify tumors that have a similar prognosis and so they are treated in a similar way. Patients with lower stage numbers tend to have a better prognosis.
Occult cancer TX, N0, M0: Cancer cells are seen in a sample of sputum or other lung fluids, but the location of the cancer can't be determined. Tis, N0, M0: The cancer is found only in the top layers of cells lining the air passages. It has not invaded deeper into other lung tissues and has not spread to lymph nodes or distant sites. T1, N0, M0: The cancer is no larger than 3 cm across, has not reached the membranes that surround the lungs, and does not affect the main branches of the bronchi. It has not spread to lymph nodes or distant sites. T2a, N0, M0: The cancer has 1 or more of the following features:
• The main tumor is between 3 and 5 cm across (larger than 3 cm but not larger than 5
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.
The cancer has not spread to lymph nodes or distant sites.
Stage IIA
Three main combinations of categories make up this stage.
T1, N1, M0: The cancer is no larger than 3 cm across, has not grown into the membranes that surround the lungs, and does not affect the main branches of the bronchi. It has spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites. T2a, N1, M0: The cancer has 1 or more of the following features:
• The main tumor is between 3 and 5 cm across (larger than 3 cm but not larger than 5
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.
It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.
T2b, N0, M0: The cancer has 1 or more of the following features:
• The main tumor is between 5 and 7 cm across (larger than 5 cm but not larger than 7
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.
The cancer has not spread to lymph nodes or distant sites.
Stage IIB
Two combinations of categories make up this stage.
T2b, N1, M0: The cancer has 1 or more of the following features:
• The main tumor is between 5 and 7 cm across (larger than 5 cm but not larger than 7
• The tumor involves a main bronchus, but is not within 2 cm of the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.
It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.
T3, N0, M0: The main tumor has 1 or more of the following features:
• It has grown into the chest wall, the breathing muscle that separates the chest from the
abdomen (diaphragm), the membranes surrounding the space between the lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• It invades a main bronchus and is closer than 2 cm (about ¾ inch) to the carina, but it
• It has grown into the airways enough to cause an entire lung to collapse or to cause
• Two or more separate tumor nodules are present in the same lobe of a lung.
The cancer has not spread to lymph nodes or distant sites.
Stage IIIA
Three main combinations of categories make up this stage.
T1 to T3, N2, M0: The tumor can be any size or have any of the following features
• The tumor involves a main bronchus without growing into the carina.
• The tumor has grown into the visceral pleura (the membranes surrounding the lungs).
• The cancer is partially clogging the airways.
• It has grown into the airways enough to cause an entire lung to collapse or to cause
• It has grown into the chest wall, the breathing muscle that separates the chest from the
abdomen (diaphragm), the membranes surrounding the space between the two lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• Two or more separate tumor nodules are present in the same lobe of a lung.
The cancer has also spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space behind the breastbone and in front of the heart (mediastinum). These lymph nodes are on the same side as the main lung tumor. The cancer has not spread to distant sites.
T3, N1, M0: The tumor has 1 or more of the following features:
• It has grown into the chest wall, the breathing muscle that separates the chest from the
abdomen (diaphragm), the membranes surrounding the space between the two lungs (mediastinal pleura), or membranes of the sac surrounding the heart (parietal pericardium).
• It invades a main bronchus and is closer than 2 cm to the carina, but it does not
• Two or more separate tumor nodules are present in the same lobe of a lung.
• It has grown into the airways enough to cause an entire lung to collapse or to cause
It has also spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). These lymph nodes are on the same side as the cancer. It has not spread to distant sites.
T4, N0 or N1, M0: The cancer has 1 or more of the following features:
• A tumor of any size has grown into the space behind the chest bone and in front of the
heart (mediastinum), the heart, the large blood vessels near the heart (such as the aorta), the windpipe, the esophagus (tube connecting the throat to the stomach), the backbone, or the carina.
• Two or more separate tumor nodules are present in different lobes of the same lung.
It may also have spread to lymph nodes within the lung and/or around the area where the bronchus enters the lung (hilar lymph nodes). Any affected lymph nodes are on the same side as the cancer. It has not spread to distant sites.
Stage IIIB
Two combinations of categories make up this stage.
Any T, N3, M0: The cancer can be of any size. It may or may not have grown into nearby structures or caused pneumonia or lung collapse. It has spread to lymph nodes near the collarbone on either side, and/or has spread to hilar or mediastinal lymph nodes on the side opposite the primary tumor. The cancer has not spread to distant sites. T4, N2, M0: The cancer has 1 or more of the following features:
• A tumor of any size has grown into the space behind the chest bone and in front of the
heart (mediastinum), the heart, the large blood vessels near the heart (such as the aorta), the windpipe, the esophagus (tube connecting the throat to the stomach), the backbone, or the carina.
• Two or more separate tumor nodules are present in different lobes of the same lung.
The cancer has also spread to lymph nodes around the carina (the point where the windpipe splits into the left and right bronchi) or in the space behind the breastbone and in front of the heart (mediastinum). Affected lymph nodes are on the same side as the main lung tumor. It has not spread to distant sites.
Two combinations of categories make up this stage.
Any T, any N, M1a: The cancer can be any size and may or may not have grown into nearby structures or reached nearby lymph nodes. In addition, any of the following is true:
• The cancer has spread to the other lung.
• Cancer cells are found in the fluid around the lung (called a malignant pleural
• Cancer cells are found in the fluid around the heart (called a malignant pericardial Any T, any N, M1b: The cancer can be any size and may or may not have grown into nearby structures or reached nearby lymph nodes. It has spread to distant sites, such as another organ.
Survival rates for lung carcinoid tumors
Survival rates are a way for doctors to discuss and compare the prognosis (outlook) for patients, usually based on the stage of the cancer or other traits. For example, the 5-year
survival rate refers to the percentage of patients who live at least 5 years after being diagnosed (although many patients live much longer than this).
Overall, the 5-year survival rate for patients with typical lung carcinoids is around 85% to 90%, and the 5-year survival rate for patients with atypical lung carcinoids is around 50% to 60%. These ranges reflect different survival rates quoted by several medical journal articles.
Because these cancers are not common, it is hard to find accurate survival rates based on the TNM stage of the cancer. But as a general rule, survival rates are likely to be higher than those listed above for people with a lung carcinoid that is still localized (confined to the area where it started), while the rates are likely to be lower for those with cancers that have metastasized.
Even with typical carcinoids that appear to have been treated successfully, in a small number of cases the cancer can recur many years later, which is why doctors often advise close follow-up for at least 10 years.
There are some important points to keep in mind when looking at survival rates such as the numbers above.
These numbers are derived from patients treated at least several years ago. Improvements in treatment since then mean that the survival rates for people now being diagnosed with these cancers may be higher.
Survival statistics can sometimes be useful as a general guide, but they may not accurately represent any one person's prognosis. A number of factors other than the type and extent of the cancer may also affect outlook, including a person's general health and the response of the cancer to treatment.
Your doctor is likely to be a good source as to whether the numbers above may apply to you, as he or she is familiar with the aspects of your particular situation.
How are lung carcinoid tumors treated? This information represents the views of the doctors and nurses serving on the American Cancer Society's Cancer Information Database Editorial Board. These views are based on their interpretation of studies published in medical journals, as well as their own professional experience. The treatment information in this document is not official policy of the Society and is not intended as medical advice to replace the expertise and judgment of your cancer care team. It is intended to help you and your family make informed decisions, together with your doctor. Your doctor may have reasons for suggesting a treatment plan different from these general treatment options. Don't hesitate to ask him or her questions about your treatment options.
The first part of this section describes the various types of treatments used for lung carcinoids. This is followed by a description of the most common approaches used based on the extent of the disease.
After the tumor is found and staged, your cancer care team will discuss your treatment options with you. The main factors in selecting a treatment for lung carcinoid tumors are the size and location of the tumor, whether it has spread to lymph nodes or other organs, and if you have any other serious medical conditions.
Selecting a treatment plan is an important decision, and you should take the time to think about all of your choices. Seeking a second opinion is often a good idea. A second opinion may provide more information and help you feel more confident about the treatment plan you choose.
Surgery is the main treatment for lung carcinoid tumors whenever possible. Most lung carcinoid tumors are cured by surgery alone. The type of surgery will depend on a number of factors, including the size and location of the tumor and whether you have any other lung problems or serious diseases. Thoracic and cardiothoracic surgeons are likely to have the most experience with these operations.
Several types of surgery are used to treat people with lung carcinoid tumors. Surgeons usually have to remove some normal lung tissue along with the tumor, but they try not to remove any more normal tissue than they need to.
These operations require general anesthesia (where you are in a deep sleep) and may also require surgical incision between the ribs in the chest (thoracotomy). You will generally need to spend 5 to 7 days in the hospital after the surgery.
Sleeve resection
To treat central carcinoids of a large airway, the surgeon may do a sleeve resection. If you think of the large airway with a tumor as similar to the sleeve of a shirt with a stain an inch or 2 above the wrist, the sleeve resection would be like cutting across the sleeve above and below the stain and sewing the cuff back onto the shortened sleeve.
Wedge resection
For small carcinoids found at the edges of the lungs away from the large airways, the surgeon may remove a wedge-shaped piece of the lung in an operation called a wedge resection or segmental resection.Lobectomy
If it is not possible to do a sleeve or wedge resection because of the size or location of the tumor, the surgeon will usually do a lobectomy, in which an entire lobe of the lung is removed. In some cases 2 lobes may be removed (bilobectomy).
Pneumonectomy
In rare cases where the cancer is in many spots or is in a place that makes it hard to remove, it may be necessary to remove the entire left or right lung in an operation called a pneumonectomy.
With any of these operations, lymph nodes near the lungs are usually removed to look for possible spread of the cancer. This is important because about 10% of typical carcinoids and 30% to 50% of atypical carcinoids will have spread to lymph nodes by the time they are diagnosed. If these nodes are not removed, it might increase the risk of the carcinoid tumor spreading even farther, to other organs. If this happens, you may no longer be able to be cured by surgery. Removing the lymph nodes also provides some indication of your risk of having the cancer come back.
Video-assisted thoracic surgery (VATS)
This is a less invasive procedure for treating some cancers in the lungs. During this operation, a thin telescopic tube with a tiny video camera on the end is placed through a small hole in the chest to help the surgeon see the chest cavity. One or two other small holes are created in the skin, and long instruments passed though these holes are used to remove the tumor. Because only small incisions are needed, there is a little less pain after the surgery. Another advantage of this surgery is a shorter hospital stay -- usually around 4 to 5 days.
Most experts recommend that only tumors smaller than 4 to 5 cm (about 2 inches) across be treated with this method. This would apply to most carcinoids. The cure rate after this surgery seems to be the same as using older techniques. It is important, though, that the surgeon performing this procedure be experienced since it requires a great deal of technical skill.
Possible side effects of surgery
Possible complications depend on the extent of the surgery and the person's health beforehand. Serious complications can include excessive bleeding, wound infections, and pneumonia.
Because the surgeon must spread the ribs to get to the lung in patients undergoing a thoracotomy, the incision will hurt for some time after surgery. Your activity will be limited for at least a month or two.
If your lungs are in good condition (other than the presence of the cancer) you can usually return to normal activities after a lobe or even an entire lung has been removed. If
you also have non-cancerous diseases such as emphysema or chronic bronchitis (which are common among heavy smokers), you may become short of breath with activities after surgery.
Surgery to relieve symptoms from lung carcinoid tumors
If you can't have major surgery because of reduced lung function or other serious medical problems, or if the cancer is widespread, other types of surgery may be used to relieve some symptoms.
For example, if the tumor is blocking airways and it might lead to pneumonia or shortness of breath, removing most of the tumor through a bronchoscope or vaporizing most of it with a laser can be helpful. These treatments, called palliative procedures, can relieve symptoms, but they cannot cure the cancer and are recommended only if you cannot have surgery to completely remove the tumor. If you are treated with these procedures you may also get radiation therapy (see the section “Radiation therapy”).
Sometimes fluid can build up in the chest cavity (outside of the lungs) and interfere with breathing. To remove the fluid and keep it from coming back, doctors sometimes perform a procedure called pleurodesis. A small cut is made in the skin of the chest wall, and a hollow tube is placed into the chest to remove the fluid. Either talc or a drug such as doxycycline or a chemotherapy drug is then instilled into the chest cavity. This causes the linings of the lung (visceral pleura) and chest wall (parietal pleural) to stick together, sealing the space and preventing further fluid buildup. The tube is generally left in for a day or two to drain any new fluid that might collect.
For more general information about surgery, please see the separate American Cancer Society document, Surgery.
Chemotherapy is the use of anti-cancer drugs that are injected into a vein or taken by mouth. These drugs enter the bloodstream and reach all areas of the body, making this treatment useful for some types of lung cancer that have spread or metastasized to organs beyond the lungs.
Unfortunately, carcinoid tumors usually do not respond very well to chemotherapy. Chemotherapy is mainly used for carcinoid tumors that have spread to other organs, are causing severe symptoms, and have not responded to other medicines. In some cases it may be given after surgery
Because chemotherapy does not always shrink carcinoid tumors, it is important to ask your doctors if your chances of benefit outweigh the side effects you may have.
Some of the chemotherapy drugs that may be used for advanced lung carcinoids include:
In most cases, several chemotherapy drugs are used together, often in combination with other types of medicines.
Doctors give chemotherapy in cycles, with each period of treatment followed by a rest period to allow the body time to recover. Chemotherapy cycles generally last about 3 to 4 weeks, and initial treatment typically involves 4 to 6 cycles. Chemotherapy is often not recommended for patients in poor health, but advanced age by itself is not a barrier to getting chemotherapy.
Possible side effects of chemotherapy
Chemotherapy drugs work by attacking cells that are dividing quickly, which is why they work against cancer cells. But other cells in the body, such as those in the bone marrow, the lining of the mouth and intestines, and the hair follicles, also divide quickly. These cells are also likely to be affected by chemotherapy, which can lead to side effects.
The side effects of chemotherapy depend on the type and dose of drugs given and the length of time they are taken. Common side effects include:
• Increased chance of infections (caused by low white blood cell counts)
• Easy bruising or bleeding (from low blood platelet counts)
• Fatigue (due to low red blood cell counts)
These side effects are usually short-term and go away after treatment is finished. There are often ways to lessen these side effects or keep them from occurring. For example, drugs can be given to help prevent or reduce nausea and vomiting.
Some drugs such as cisplatin can damage nerves (a condition called neuropathy). This may lead to symptoms (mainly in the hands and feet) such as pain, burning or tingling sensations, sensitivity to cold or heat, or weakness. In most cases this goes away once treatment is stopped, but it may last a long time in some people. You should report this -- as well as any other side effects or changes you notice while getting chemotherapy -- to
your medical team so that it can be treated promptly. In some cases, the doses of the chemotherapy drugs may need to be reduced or treatment may need to be delayed or stopped to prevent the effects from getting worse.
For more general information about chemotherapy, please see the separate American Cancer Society document, Understanding Chemotherapy: A Guide for Patients and Families.
Other drugs for treating carcinoid tumors
For people with metastatic carcinoid tumors who have carcinoid syndrome (facial flushing, diarrhea, wheezing, rapid heart rate), several medicines can help control the symptoms and may help keep the tumor from growing for a time.
Octreotide
This drug is related to somatostatin, a natural hormone that seems to help slow the growth of neuroendocrine cells. It is very helpful in treating the symptoms of carcinoid syndrome. Sometimes octreotide can temporarily shrink carcinoid tumors, but it does not cure them. Side effects can include pain or burning at the injection site, stomach cramps, nausea, vomiting, headaches, dizziness, and fatigue.
The original version of octreotide (Sandostatin®) is given as an injection under the skin (subcutaneously) at least twice daily. Some people can learn to give this injection themselves at home. A newer, long-acting version of the drug (Sandostatin LAR®) is given as an injection into a muscle once a month by your doctor or nurse. When first starting treatment, most people are given injections every day. Once the doctor finds the correct dose, the longer-acting monthly injection may be used.
Lanreotide
Lanreotide (Somatuline®) is a drug similar to octreotide. It is given as an injection under the skin once a month. It may be given by your doctor or nurse, or you may learn how to give the injection at home. Side effects are similar to those of octreotide, although pain at the injection site is less common.
Interferons
These drugs are natural substances that normally help activate the body's immune system. They also suppress the growth of some tumors. Interferon alfa is sometimes helpful in shrinking or slowing the growth of metastatic carcinoid tumors and improving symptoms of carcinoid syndrome. But its usefulness is limited by its flu-like side effects, which may be severe. It can also cause depression. Interferon alfa is given by injection, either daily or several times a week.
Other medicines can be used to help control specific symptoms. It is important to describe your symptoms to your doctor so that they can be treated effectively.
Radiation therapy is the use of high-energy radiation in the form of x-rays or radioactive particles to kill cancer cells. Unfortunately, radiation therapy usually has only a limited effect on lung carcinoid tumors.
Although surgery is the main treatment for most carcinoid tumors, radiation therapy may be an option for those who can't have surgery for some reason. It may also be given after surgery in some cases if there's a chance some of the tumor was not removed. Radiation therapy can also be used to help relieve symptoms such as pain if the cancer has spread to the bones or other areas.
External beam radiation therapy
External beam radiation therapy uses a machine that delivers a beam of radiation to a specific part of the body. This is the type of radiation used most often for lung carcinoid tumors.
Before your treatments start, the radiation team will determine the correct angles for aiming the radiation beams and the proper dose of radiation. Radiation therapy is much like getting an x-ray, but the radiation is more intense (stronger). The procedure itself is painless. Each treatment lasts only a few minutes, although the setup time -- getting you into place for treatment -- usually takes longer. Most often, radiation treatments are given 5 days a week for several weeks.
The main side effects of lung radiation therapy are fatigue (tiredness) and temporary sunburn-like skin changes. If high doses are given, radiation therapy can cause scar tissue to form in the lungs, which can lead to trouble breathing and an increased susceptibility to infection.
Radioactive drugs
Drugs containing radioactive particles may be useful in treating some widespread carcinoid tumors. For this type of treatment, doctors use some of the same drugs used in radionuclide scans (see "How are lung carcinoid tumors diagnosed?"), such as MIBG and octreotide. These drugs attach to carcinoid tumor cells. By using more strongly radioactive particles than are used in the scans, doctors can deliver higher doses of radiation directly to the tumors. Some early results have been promising, but this type of treatment is not widely used at this time.
For more general information about radiation therapy, please see the separate American Cancer Society document, Understanding Radiation Therapy: A Guide for Patients and Families.
You may have had to make a lot of decisions since you've been told you have cancer. One of the most important decisions you will make is choosing which treatment is best
for you. You may have heard about clinical trials being done for your type of cancer. Or maybe someone on your health care team has mentioned a clinical trial to you.
Clinical trials are carefully controlled research studies that are done with patients who volunteer for them. They are done to get a closer look at promising new treatments or procedures.
If you would like to take part in a clinical trial, you should start by asking your doctor if your clinic or hospital conducts clinical trials. You can also call our clinical trials matching service for a list of clinical trials that meet your medical needs. You can reach this service at 1-800-303-5691 or on our Web site at www.cancer.org/clinicaltrials. You can also get a list of current clinical trials by calling the National Cancer Institute's Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) or by visiting the NCI clinical trials Web site at www.cancer.gov/clinicaltrials.
There are requirements you must meet to take part in any clinical trial. If you do qualify for a clinical trial, it is up to you whether or not to enter (enroll in) it.
Clinical trials are one way to get state-of-the art cancer treatment. They are the only way for doctors to learn better methods to treat cancer. Still, they are not right for everyone.
You can get a lot more information on clinical trials in our document called Clinical Trials: What You Need to Know. You can read it on our Web site or call our toll-free number (1-800-227-2345) and have it sent to you.
When you have cancer you are likely to hear about ways to treat your cancer or relieve symptoms that your doctor hasn't mentioned. Everyone from friends and family to Internet groups and Web sites offer ideas for what might help you. These methods can include vitamins, herbs, and special diets, or other methods such as acupuncture or massage, to name a few.
What exactly are complementary and alternative therapies?
Not everyone uses these terms the same way, and they are used to refer to many different methods, so it can be confusing. We use complementary to refer to treatments that are used along with your regular medical care. Alternative treatments are used instead of a doctor's medical treatment.
Complementary methods: Most complementary treatment methods are not offered as cures for cancer. Mainly, they are used to help you feel better. Some methods that are used along with regular treatment are meditation to reduce stress, acupuncture to help relieve pain, or peppermint tea to relieve nausea. Some complementary methods are known to help, while others have not been tested. Some have been proven not be helpful, and a few have even been found harmful. Alternative treatments: Alternative treatments may be offered as cancer cures. These treatments have not been proven safe and effective in clinical trials. Some of these
methods may pose danger, or have life-threatening side effects. But the biggest danger in most cases is that you may lose the chance to be helped by standard medical treatment. Delays or interruptions in your medical treatments may give the cancer more time to grow and make it less likely that treatment will help.
Finding out more
It is easy to see why people with cancer think about alternative methods. You want to do all you can to fight the cancer, and the idea of a treatment with no side effects sounds great. Sometimes medical treatments like chemotherapy can be hard to take, or they may no longer be working. But the truth is that most of these alternative methods have not been tested and proven to work in treating cancer.
As you consider your options, here are 3 important steps you can take:
• Look for "red flags" that suggest fraud. Does the method promise to cure all or most
cancers? Are you told not to have regular medical treatments? Is the treatment a "secret" that requires you to visit certain providers or travel to another country?
• Talk to your doctor or nurse about any method you are thinking about using.
• Contact us at 1-800-227-2345 to learn more about complementary and alternative
methods in general and to find out about the specific methods you are looking at.
The choice is yours
Decisions about how to treat or manage your cancer are always yours to make. If you want to use a non-standard treatment, learn all you can about the method and talk to your doctor about it. With good information and the support of your health care team, you may be able to safely use the methods that can help you while avoiding those that could be harmful.
Treatment of lung carcinoid by type and extent of disease
The treatment of lung carcinoid tumors depends to a large extent on the type (typical versus atypical) and extent of the cancer. Other factors, such as a person's overall health and ability to withstand surgery, are also important.
Many doctors describe the extent of these cancers using the TNM staging system (see "How are lung carcinoid tumors staged?"). But for treatment purposes most doctors divide these tumors into localized cancers and metastatic cancers.
Localized carcinoid tumors
Localized carcinoid tumors haven't spread beyond where they started. In the TNM staging system, this includes stages I, II, and some stage III cancers.
These cancers are treated with surgery whenever possible. The extent of the surgery depends on the size and location of the cancer. Nearby lymph nodes are typically removed as well, especially if you have an atypical carcinoid.
Most patients with localized lung carcinoid tumors are cured with surgery alone and don't need other treatments. Some experts recommend additional treatment for people with an atypical carcinoid that has spread to lymph nodes. This can be chemotherapy, radiation therapy or both. But it's not clear if the added therapy helps people live longer.
For people with localized cancers who can't have surgery, most doctors recommend radiation therapy for typical carcinoids and chemotherapy and radiation therapy for atypical carcinoids.
Metastatic carcinoid tumors
The treatment of a metastatic carcinoid tumor depends on where the cancer is and whether you have symptoms of the carcinoid syndrome. In general, it is a slow-growing cancer, and chemotherapy has not proven very successful. If you have only a small number of tumors that can be removed, surgery (on both the lung and at the site of metastasis) is your best option.
Lung carcinoid tumors usually spread to the liver first. If the carcinoid has spread only to your liver but can't be removed there with standard surgery, another option might be to have a liver transplant. This is a very involved operation that most doctors still consider experimental. It is done at only a few transplant centers.
If the carcinoid is in your liver and is causing symptoms, a procedure called hepatic artery embolization may be helpful. It may relieve symptoms or slow the growth of the cancer, although it is very unlikely to result in a cure. This technique reduces the blood flow in the hepatic artery, the artery that feeds most cancer cells in the liver. This is done by injecting materials that plug up the artery. Most of the healthy liver cells will not be affected because they get their blood supply from the portal vein. For this procedure, a catheter is put into an artery in the inner thigh and threaded up into the liver. A dye is usually injected into the bloodstream at this time to allow the doctor to monitor the path of the catheter with a special type of x-ray. Once the catheter is in place, small particles are injected into the artery to plug it up. Embolization also reduces some of the blood supply to the normal liver tissue. This may be dangerous for patients with other diseases of the liver such as hepatitis or cirrhosis.
If your liver cannot be treated directly, or if the carcinoid has spread to other parts of your body, then drug therapy can be helpful. The most useful are octreotide or lanreotide, which can stop the secretion of the chemicals that cause the carcinoid syndrome and also can sometimes actually shrink the cancers. Another drug, interferon alfa, can act the same way. Sometimes these 2 types of drugs are given together. Adding chemotherapy may also help reduce symptoms, but it seldom shrinks the tumor very much more.
External radiation therapy can be used to relieve symptoms caused by tumors such as bone pain. For more widespread disease, radioactive drugs may be helpful.
Recurrent carcinoid tumors
When cancer comes backs after treatment, it is called a recurrence. Recurrence can be local (in or near the same place it started) or distant (spread to organs such as the liver or bone). Some carcinoid tumors come back, sometimes several years after the initial treatment. If this happens, further treatment options depend on where the cancer is and what treatments have already been used. Cancers that recur locally or in only 1 or 2 areas can sometimes be treated with further surgery. If surgery is not an option, radiation therapy, chemotherapy, or other drugs may be tried. Because recurrent cancers can often be hard to treat, clinical trials of new types of treatment may be a good option.
For more details on treatment options -- including some that may not be addressed in this document -- the National Comprehensive Cancer Network (NCCN) and the National Cancer Institute (NCI) are good sources of information.
The NCCN, made up of experts from many of the nation's leading cancer centers, develops cancer treatment guidelines for doctors to use when treating patients. These are available on the NCCN Web site (www.nccn.org).
The NCI provides treatment guidelines via its telephone information center (1-800-4-CANCER) and its Web site (www.cancer.gov). Detailed guidelines intended for use by cancer care professionals are also available on www.cancer.gov.
What should you ask your doctor about lung carcinoid tumors?
It is important to have frank, open discussions with your cancer care team. They want to answer all of your questions, no matter how minor you might think they are. For instance, consider these questions:
• What kind of carcinoid tumor do I have?
• Has my carcinoid tumor spread beyond the lungs?
• What is the stage (extent) of my carcinoid tumor, and what does that mean in my
• Are there other tests that need to be done before we can decide on treatment?
• How much experience do you have treating this type of cancer?
• What risks or side effects are there to the treatments you suggest?
• What should I do to be ready for treatment?
• How long will treatment last? What will it involve? Where will it be done?
• How will treatment affect my daily activities?
• What are the chances of recurrence of my carcinoid tumor with these treatment plans?
• What would we do if the treatment doesn't work or if the cancer recurs?
• What type of follow-up might I need after treatment?
Along with these sample questions, be sure to write down some of your own. For instance, you might want more information about recovery time so that you can plan your work schedule. Or you may want to ask about clinical trials for which you may qualify.
What happens after treatment for lung carcinoid tumors?
Completing treatment can be both stressful and exciting. You will be relieved to finish treatment, yet it is hard not to worry about cancer coming back. (When cancer returns, it is called recurrence.) This is a very common concern among those who have had cancer.
It may take a while before your confidence in your own recovery begins to feel real and your fears are somewhat relieved. Even with no recurrences, people who have had cancer learn to live with uncertainty.
After your treatment is over, it is very important to keep all follow-up appointments. During these visits, your doctors will ask about symptoms, do physical exams, and may order blood tests or imaging studies such as CT scans or x-rays. Your doctor will most likely want to see you fairly frequently (every couple of months or so) at first. The time between visits may be extended if there are no problems. Although lung carcinoid tumors are often cured by the initial treatment, in a small number of cases the cancer can recur many years later, which is why doctors often advise close follow-up for at least 10 years.
Follow-up is needed to check for cancer recurrence or spread, as well as possible side effects of certain treatments. This is the time for you to ask your health care team any questions you need answered and to discuss any concerns you might have.
Almost any cancer treatment can have side effects. Some may last for a few weeks to several months, but others can be permanent. Don't hesitate to tell your cancer care team about any symptoms or side effects that bother you so they can help you manage them.
If the cancer does recur at some point, further treatment will depend on the location of the cancer, what treatments you've had before, and your health. For more information on how
recurrent cancer is treated, see the section "Treatment of lung carcinoid by type and extent of disease." For more general information on dealing with a recurrence, you may also want to see the American Cancer Society document, When Your Cancer Comes Back: Cancer Recurrence. You can get this document by calling 1-800- 227-2345.
At some point after your cancer diagnosis and treatment, you may find yourself in the office of a new doctor. Your original doctor may have moved or retired, or you may have moved or changed doctors for some reason. It is important that you be able to give your new doctor the exact details of your diagnosis and treatment. Make sure you have the following information handy:
• A copy of your pathology report(s) from any biopsies or surgeries
• If you had surgery, a copy of your operative report(s)
• If you were hospitalized, a copy of the discharge summary that doctors must prepare
• If you had radiation therapy, a summary of the type and dose of radiation and when
• If you had chemotherapy or other medicines, a list of your drugs, drug doses, and
It is also important to keep your health insurance. Even though no one wants to think of their cancer coming back, it is always a possibility. If it happens, the last thing you want is to have to worry about paying for treatment.
Lifestyle changes to consider during and after treatment
Having cancer and dealing with treatment can be time-consuming and emotionally draining, but it can also be a time to look at your life in new ways. Maybe you are thinking about how to improve your health over the long term. Some people even begin this process during cancer treatment.
Make healthier choices
Think about your life before you learned you had cancer. Were there things you did that might have made you less healthy? Maybe you drank too much alcohol, or ate more than you needed, or smoked, or didn’t exercise very often. Emotionally, maybe you kept your feelings bottled up, or maybe you let stressful situations go on too long.
Now is not the time to feel guilty or to blame yourself. However, you can start making changes today that can have positive effects for the rest of your life. Not only will you feel better but you will also be healthier. What better time than now to take advantage of the motivation you have as a result of going through a life-changing experience like having cancer?
You can start by working on those things that you feel most concerned about. Get help with those that are harder for you. For instance, if you are thinking about quitting smoking and need help, call the American Cancer Society at 1-800-227-2345.
Diet and nutrition
Eating right can be a challenge for anyone, but it can get even tougher during and after cancer treatment. For instance, treatment often may change your sense of taste. Nausea can be a problem. You may lose your appetite for a while and lose weight when you don’t want to. On the other hand, some people gain weight even without eating more. This can be frustrating, too.
If you are losing weight or have taste problems during treatment, do the best you can with eating and remember that these problems usually improve over time. You may want to ask your cancer team for a referral to a dietitian, an expert in nutrition who can give you ideas on how to fight some of the side effects of your treatment. You may also find it helps to eat small portions every 2 to 3 hours until you feel better and can go back to a more normal schedule.
One of the best things you can do after treatment is to put healthy eating habits into place. You will be surprised at the long-term benefits of some simple changes, like increasing the variety of healthy foods you eat. Try to eat 5 or more servings of vegetables and fruits each day. Choose whole grain foods instead of white flour and sugars. Try to limit meats that are high in fat. Cut back on processed meats like hot dogs, bologna, and bacon. Get rid of them altogether if you can. If you drink alcohol, limit yourself to 1 or 2 drinks a day at the most. And don't forget to get some type of regular exercise. The combination of a good diet and regular exercise will help you maintain a healthy weight and keep you feeling more energetic.
Rest, fatigue, work, and exercise
Fatigue is a very common symptom in people being treated for cancer. This is often not an ordinary type of tiredness but a "bone-weary" exhaustion that doesn't get better with rest. For some, this fatigue lasts a long time after treatment, and can discourage them from physical activity.
However, exercise can actually help you reduce fatigue. Studies have shown that patients who follow an exercise program tailored to their personal needs feel physically and emotionally improved and can cope better.
If you are ill and need to be on bed rest during treatment, it is normal to expect your fitness, endurance, and muscle strength to decline some. Physical therapy can help you maintain strength and range of motion in your muscles, which can help fight fatigue and the sense of depression that sometimes comes with feeling so tired.
Any program of physical activity should fit your own situation. An older person who has never exercised will not be able to take on the same amount of exercise as a 20-year-old
who plays tennis 3 times a week. If you haven't exercised in a few years but can still get around, you may want to think about taking short walks.
Talk with your health care team before starting, and get their opinion about your exercise plans. Then, try to get an exercise buddy so that you're not doing it alone. Having family or friends involved when starting a new exercise program can give you that extra boost of support to keep you going when the push just isn't there.
If you are very tired, though, you will need to balance activity with rest. It is okay to rest when you need to. It is really hard for some people to allow themselves to do that when they are used to working all day or taking care of a household.
Exercise can improve your physical and emotional health.
• It improves your cardiovascular (heart and circulation) fitness.
• It makes you feel generally happier.
• It helps you feel better about yourself.
And long term, we know that exercise plays a role in preventing some cancers. The American Cancer Society, in its guidelines on physical activity for cancer prevention, recommends that adults take part in at least 1 physical activity for 30 minutes or more on 5 days or more of the week. Children and teens are encouraged to try for at least 60 minutes a day of energetic physical activity on at least 5 days a week.
Once your treatment ends, you may find yourself overwhelmed by emotions. This happens to a lot of people. You may have been going through so much during treatment that you could only focus on getting through your treatment.
Now you may find that you think about the potential of your own death, or the effect of your cancer on your family, friends, and career. You may also begin to re-evaluate your relationship with your spouse or partner. Unexpected issues may also cause concern -- for instance, as you become healthier and have fewer doctor visits, you will see your health care team less often. That can be a source of anxiety for some.
This is an ideal time to seek out emotional and social support. You need people you can turn to for strength and comfort. Support can come in many forms: family, friends, cancer support groups, church or spiritual groups, online support communities, or individual counselors.
Almost everyone who has been through cancer can benefit from getting some type of support. What's best for you depends on your situation and personality. Some people feel
safe in peer-support groups or education groups. Others would rather talk in an informal setting, such as church. Others may feel more at ease talking one-on-one with a trusted friend or counselor. Whatever your source of strength or comfort, make sure you have a place to go with your concerns.
The cancer journey can feel very lonely. It is not necessary or realistic to go it all by yourself. And your friends and family may feel shut out if you decide not to include them. Let them in -- and let in anyone else who you feel may help. If you aren't sure who can help, call your American Cancer Society at 1-800-227-2345 and we can put you in touch with an appropriate group or resource.
You can't change the fact that you have had cancer. What you can change is how you live the rest of your life -- making healthy choices and feeling as well as possible, physically and emotionally.
What happens if treatment is no longer working?
If cancer continues to grow after one kind of treatment, or if it returns, it is often possible to try another treatment plan that might still cure the cancer, or at least shrink the tumors enough to help you live longer and feel better. On the other hand, when a person has received several different medical treatments and the cancer has not been cured, over time the cancer tends to become resistant to all treatment. At this time it's important to weigh the possible limited benefit of a new treatment against the possible downsides, including continued doctor visits and treatment side effects.
Everyone has his or her own way of looking at this. Some people may want to focus on remaining comfortable during their limited time left.
This is likely to be the most difficult time in your battle with cancer -- when you have tried everything medically within reason and it's just not working anymore. Although your doctor may offer you new treatment, you need to consider that at some point, continuing treatment is not likely to improve your health or change your prognosis or survival.
If you want to continue treatment to fight your cancer as long as you can, you still need to consider the odds of more treatment having any benefit. In many cases, your doctor can estimate the response rate for the treatment you are considering. Some people are tempted to try more chemotherapy or radiation, for example, even when their doctors say that the odds of benefit are less than 1%. In this situation, you need to think about and understand your reasons for choosing this plan.
No matter what you decide to do, it is important that you be as comfortable as possible. Make sure you are asking for and getting treatment for any symptoms you might have, such as pain. This type of treatment is called palliative treatment.
Palliative treatment helps relieve these symptoms, but is not expected to cure the disease; its main purpose is to improve your quality of life. Sometimes, the treatments you get to control your symptoms are similar to the treatments used to treat cancer. For example, radiation therapy might be given to help relieve bone pain from bone metastasis. Or
chemotherapy might be given to help shrink a tumor and keep it from causing a bowel obstruction. But this is not the same as receiving treatment to try to cure the cancer.
At some point, you may benefit from hospice care. Most of the time, this is given at home. Your cancer may be causing symptoms or problems that need attention, and hospice focuses on your comfort. You should know that receiving hospice care doesn't mean you can't have treatment for the problems caused by your cancer or other health conditions. It just means that the focus of your care is on living life as fully as possible and feeling as well as you can at this difficult stage of your cancer.
Remember also that maintaining hope is important. Your hope for a cure may not be as bright, but there is still hope for good times with family and friends -- times that are filled with happiness and meaning. In a way, pausing at this time in your cancer treatment is an opportunity to refocus on the most important things in your life. This is the time to do some things you've always wanted to do and to stop doing the things you no longer want to do.
What's new in lung carcinoid tumor research and treatment?
Many medical centers across the nation are researching the causes and treatment of lung carcinoid tumors. This is a challenging disease to study because it is not common. But each year, scientists find out more about what causes the disease and how to improve treatment.
Researchers have made great progress in understanding how certain changes in DNA can cause normal cells to become cancerous. DNA is the molecule that carries the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA.
However, DNA affects more than how we look. Some genes (parts of our DNA) contain instructions for controlling when our cells grow and divide. Certain genes that cause cells to grow and divide into new cells are called oncogenes. Others that slow down cell division or cause cells to die at the right time are called tumor suppressor genes. Cancers can be caused by DNA mutations (defects) that turn on oncogenes or turn off tumor suppressor genes. Researchers have characterized many of the DNA changes in lung carcinoids in the past few years. Continued research in understanding these changes will lead to new tests for earlier diagnosis and new drugs for more effective treatment.
Because the outlook and treatment of lung carcinoids and other types of lung cancer are very different, accurate diagnosis is important. Researchers have made great progress in developing tests that can detect specific substances found in the cells of carcinoid tumors
but not other lung cancers. Most of these tests treat tissue samples with special man-made antibodies in the lab. The antibodies are designed to recognize specific substances in certain types of tumors.
Doctors are learning how to treat lung carcinoids more effectively. For example, newer surgical techniques allow doctors to remove parts of the lung through smaller incisions, which can result in shorter hospital stays and less pain for patients. And new radiation therapy techniques help doctors focus the radiation more precisely on tumors, lowering the amount of radiation that normal tissues get and reducing side effects.
Metastatic carcinoid tumors remain hard to treat. Most carcinoid tumors grow fairly slowly. Because standard chemotherapy drugs work by attacking quickly growing cells, they are not very effective against carcinoid tumors. Newer drugs, called targeted therapies, are aimed at specific parts of cancer cells and may prove to be more effective against carcinoids.
Targeted drugs known as angiogenesis inhibitors affect the growth of new blood vessels (angiogenesis), which tumors need to grow larger. Some of these drugs are already used to treat other types of cancer and are now being studied for use against carcinoid tumors. Examples of these drugs include thalidomide (Thalomid®), bevacizumab (Avastin®), and pazopanib.
Another group of targeted drugs being studied for use against carcinoid tumors are known as mTOR inhibitors. Examples include temsirolimus (Torisel®) and everolimus (Certican®).
These and other new drugs are now being studied in clinical trials.
Additional resources
More information from your American Cancer Society
We have some related information that may also be helpful to you. These materials can be ordered from our toll-free number 1-800-227-2345.
After Diagnosis: A Guide for Patients and Families (also available in Spanish)
Caring for the Patient With Cancer at Home: A Guide for Patients and Families (also available in Spanish)
Pain Control: A Guide for Those With Cancer and Their Loved Ones (also available in Spanish)
Understanding Chemotherapy: A Guide for Patients and Families (also available in Spanish)
Understanding Radiation Therapy: A Guide for Patients and Families (also available in Spanish)
When Your Cancer Comes Back: Cancer Recurrence
The following books are available from the American Cancer Society. Call us at 1-800-227-2345 to ask about costs or to place your order.
Cancer in the Family: Helping Children Cope With a Parent's Illness Caregiving: A Step-By-Step Resource for Caring for the Person with Cancer at Home
In addition to the American Cancer Society, other sources of patient information and support include:
The Carcinoid Cancer Foundation, Inc. Toll-free number: 1-888-722-3132 or 1-914-683-1001 Web site:www.carcinoid.org Lung Cancer Alliance Toll-free number: 1-800-298-2436 or 1-202-463-2080 Web site: www.lungcanceralliance.org National Cancer Institute Toll-free number 1-800-4-CANCER (1-800-422-6237) TTY: 1-800-332-8615 Web site: www.cancer.gov *Inclusion on this list does not imply endorsement by the American Cancer Society.
No matter who you are, we can help. Contact us anytime, day or night, for information and support. Call us at 1-800-227-2345 or visit www.cancer.org.
References
American Joint Committee on Cancer. Lung. AJCC Cancer Staging Manual. 7th ed. New York: Springer. 2010:253–266.
Bertino EM, Confer PD, Colonna JE, Ross P, Otterson GA. Pulmonary neuroendocrine/carcinoid tumors: a review article. Cancer. 2009;115(19):4434–4441.
Gustafsson BI, Kidd M, Chan A, et al. Bronchopulmonary neuroendocrine tumors. Cancer. 2008,113:5–21.
Hage R, de la Riviere B, Selenrijk CA, et al. Update in pulmonary carcinoid tumors: A review article. Ann Surg Oncol. 2003;10:697–703.
Kosmidis PA. Treatment of carcinoid of the lung. Curr Opinion Oncol. 2004;16:146–149.
Krug LM, Kris MG, Rosenzweig K, Travis WD. Small cell and other neuroendocrine tumors of the lung. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg'sCancer: Principles and Practice of Oncology. 8th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2008: 946–971.
Kulke MH, Mayer RJ. Carcinoid tumors. New Engl J Med. 1999;340:858–868.
Modlin IM, Lye KD, Kidd M. A 5-decade analysis of 13,715 cases of carcinoid tumors. Cancer. 2003;97:934–959.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Neuroendocrine tumors. V.2.2009. Accessed at www.nccn.org on March 1, 2010.
Pinchot SN, Holen K, Sippel RS, Chen H. Carcinoid tumors. Oncologist. 2008;13:1255–1269.
Rosai J. Rosai and Ackerman'sSurgical Pathology. 9th Ed. New York, NY: Mosby; 2004: 407–412.
Sachithanandan N, Harle RA, Burgess JR. Bronchopulmonary carcinoid in multiple endocrine neoplasia type 1. Cancer. 2005;103:509–515.
Zuetenhorst JM, Taal BG. Metastatic carcinoid tumors: A clinical review. Oncologist. 2005;10:123–131.
Alliance CompleteCare Future Formulary Change File CMS FORMULARY ID: 13348 EFFECTIVE DATE: 6/1/2013 DRUG NAME DILANTIN 50 MG ORAL CHANGE DESCRIPTION BRAND DELETION, ADD FRF GENERIC REASON DESCRIPTION REMOVAL OF BRAND NAME DRUG FROM FORMULARY DUE TO ADDITION OF NEW GENERIC EQUIVALENT. OTHER POSSIBLE DRUGS Alliance CompleteCare Future Formulary
SAFETY DATA SHEET SECTION 1: IDENTIFICATION OF THE SUBSTANCE AND SUPPLIER Product name: ALBENDAZOLE Sheep Product code: Recommended use: For the control of albendazole sensitive roundworms, tapeworms, lungworms and adult fluke in sheep. Company details: Address: Telephone number: Phone: +64 9 980 1600 Fax: +64 9 980 1601 Emergency telephone National Poi
Lung Carcinoid Tumor 
A thin lining called the pleura surrounds the lungs. The pleura protects your lungs and helps them slide back and forth as they expand and contract during breathing. The chest cavity is called the pleural cavity.
Carcinoid tumors start from cells of the diffuse neuroendocrine system. This system is made up of cells that are like nerve cells in certain ways and like hormone-making endocrine cells in other ways. These cells do not form an actual organ like the adrenal or thyroid glands. Instead, they are scattered throughout the body in organs like the lungs, stomach, and intestines.
Neuroendocrine cells make hormones like adrenaline and adrenaline-like substances. In the lungs, this may help control air flow and blood flow and may help control the growth of other types of lung cells. Neuroendocrine cells may detect decreased oxygen or increased carbon dioxide in the air we breathe and then release chemical messages to help the lungs adjust to these changes. People who live at higher altitudes have more lung neuroendocrine cells, probably because there is less oxygen in the air they breathe.
Like most cells in your body, lung neuroendocrine cells sometimes go through certain changes that cause them to grow too much and form tumors. These are known as neuroendocrine tumors or neuroendocrine cancers. Neuroendocrine tumors can develop anywhere in the body. Neuroendocrine tumors that begin in the digestive tract, another common site for these tumors, are discussed in a separate American Cancer Society document, Gastrointestinal Carcinoid Tumors.
This document discusses only neuroendocrine tumors that start in the lungs. 
Hage R, de la Riviere B, Selenrijk CA, et al. Update in pulmonary carcinoid tumors: A review article. Ann Surg Oncol. 2003;10:697–703.
Kosmidis PA. Treatment of carcinoid of the lung. Curr Opinion Oncol. 2004;16:146–149.
Krug LM, Kris MG, Rosenzweig K, Travis WD. Small cell and other neuroendocrine tumors of the lung. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg's Cancer: Principles and Practice of Oncology. 8th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2008: 946–971.
Kulke MH, Mayer RJ. Carcinoid tumors. New Engl J Med. 1999;340:858–868.
Modlin IM, Lye KD, Kidd M. A 5-decade analysis of 13,715 cases of carcinoid tumors. Cancer. 2003;97:934–959.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Neuroendocrine tumors. V.2.2009. Accessed at www.nccn.org on March 1, 2010.
Pinchot SN, Holen K, Sippel RS, Chen H. Carcinoid tumors. Oncologist. 2008;13:1255–1269.
Rosai J. Rosai and Ackerman's Surgical Pathology. 9th Ed. New York, NY: Mosby; 2004: 407–412.
Sachithanandan N, Harle RA, Burgess JR. Bronchopulmonary carcinoid in multiple endocrine neoplasia type 1. Cancer. 2005;103:509–515.
Zuetenhorst JM, Taal BG. Metastatic carcinoid tumors: A clinical review. Oncologist. 2005;10:123–131.