Carcinoid tumors are rare, slow-growing cancers. They usually start in the lining of the digestive tract or in the lungs. They grow slowly and don't produce symptoms in the early stages. As a result, the average age of people diagnosed with digestive or lung carcinoids is about 60.

In later stages the tumors sometimes produce hormones that can cause carcinoid syndrome. The syndrome causes flushing of the face and upper chest, diarrhea, and trouble breathing.

Surgery is the main treatment for carcinoid tumors. If they haven't spread to other parts of the body, surgery can cure the cancer.

A carcinoid tumor is a type of neuroendocrine tumor that usually develops in the digestive (GI) tract (such as the stomach or intestines) or in the lungs. In some cases, a carcinoid tumor develops in another part of the body, such as the pancreas, testicle (in men), or ovary (in women). It is a slow-growing tumor that typically does not cause symptoms in the early stages, so a person may have the tumor for years before being diagnosed. In later stages, symptoms may vary depending on where the tumor is located. Symptoms of a GI carcinoid tumor may only develop if the tumor has spread to the liver. The tumor may produce hormone-like substances that spread to the body and cause symptoms of carcinoid syndrome, such as flushing of the face and chest, diarrhea, and trouble breathing. People with a lung carcinoid tumor are less likely to have carcinoid syndrome, but may experience coughing, wheezing, or pneumonia. The tumor may also cause various symptoms if it has spread to other parts of the body.

The cause of carcinoid tumors is unknown, but certain unavoidable risk factors may increase a person's chance of developing a carcinoid tumor. In general, cancer develops when a cell randomly develops mutations in its DNA. Surgery to remove the tumor is the main treatment and can typically cure the tumor if it has not spread to other parts of the body. Other treatment options may include radiation therapy, chemotherapy, and targeted therapy.

Carcinoid tumor is rare in children and more common in adults. Experts think that carcinoid tumor affects 4 in 100,000 adults. Carcinoid tumor in children and young adults is so rare that there is little data on how many young people have it.

The cause of carcinoid tumors is currently unknown. There are some unavoidable risk factors that may increase a person's risk of developing the tumor. It is important to note that people with several risk factors may never develop cancer, while others with no risk factors may develop cancer. Possible risk factors for carcinoid tumors include:

• Family history of multiple endocrine neoplasia type 1 (MEN1). About 10% of gastrointestinal (GI) carcinoid tumors are thought to be associated with MEN1.
• Family history of neurofibromatosis type 1 (NF1).
• Family history of other genetic syndromes such as tuberous sclerosis complex and von Hippel Lindau disease.
• Other stomach conditions. People with diseases that damage the stomach and reduce stomach acid levels (in particular, pernicious anemia) have a greater risk of developing stomach carcinoid tumors.
• Race and gender. GI carcinoid tumors are more common among African Americans than among white people, and slightly more common among women than men. Lung carcinoid tumors are more common among white people than among people of other ethnicities.

Carcinoid tumors generally have been considered to be sporadic, except for a small proportion which occur as a part of multiple endocrine neoplasia (MEN) syndromes. Carcinoid tumors most notably may occur in MEN1, and occasionally in MEN2. These conditions are caused by mutations in the MEN1 and RET genes, respectively, and most cases are considered to have an autosomal dominant pattern of inheritance. When associated with these familial syndromes, carcinoids are more likely to develop in the foregut, especially in the thymus and lung.

It has been reported that even when a carcinoid tumor does not appear to be associated with MEN, there does appear to be an increased risk for developing a carcinoid tumor among first-degree relatives; this suggests that some carcinoid tumors may be familial. However, little data are available on the percentage of individuals with a carcinoid tumor that have a family history of carcinoid tumors.

Some people with carcinoid tumors have symptoms, but others don’t. The symptoms of carcinoid tumor depend on where the tumor is inside the body. 

Patients with carcinoid tumor of the appendix usually have symptoms of appendicitis, such as pain in the abdomen. They may be diagnosed later with carcinoid tumor if the doctor removes the appendix and finds a tumor. Patients with carcinoid tumor in other parts of the digestive tract may have symptoms such as:

• Pain in the abdomen
• Nausea or vomiting
• Diarrhea

Patients with carcinoid tumor in the lungs may have symptoms such as:

• Trouble breathing
• Chest pain
• Wheezing 
• Coughing up blood

Sometimes these symptoms are diagnosed as pneumonia by mistake. 

In rare cases, patients with carcinoid tumor may develop carcinoid syndrome. Carcinoid syndrome is a problem that develops from the tumors making hormones.  Symptoms include:

• Feeling flushed
• Nausea and vomiting
• Diarrhea 

Lab Tests: If you have symptoms of carcinoid tumor, your doctor will order lab tests of your urine or blood to check your hormone levels.

Imaging: Your doctor will use scans such as CT and MRI to see where the tumor is and how big it is. Different types of PET scans can also help find more fast-growing neuroendocrine cancer cells.

Biopsy: To check if the tumor is carcinoid tumor your doctor will do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope and run other tests to see what kind of tumor it is.

Treatment for each person will be unique. You should go to an expert in neuroendocrine tumor treatment to decide the best approach for your tumor. You can contact MyPART for help finding experts near you.

Surgery: If you have a carcinoid tumor, you may have surgery to remove the tumor and some surrounding tissue. Surgery is the best option for treating carcinoid tumor and preventing it from spreading.

When the carcinoid tumor is large or the cancer cells have spread to other parts of the body other treatments may include:

Somatostatin analogs: Somatostatin analogs are a type of treatment that may stop your body from making too many hormones. This may slow down the growth of the tumor when cancer cells have spread to other part of the body

Targeted therapy: Targeted therapy is a type of treatment that uses drugs that target certain genes or proteins to kill cancer cells. Neuroendocrine tumor cells have receptors on the surface of the cells called somatostatin. A type of targeted therapy called peptide receptor radionuclide therapy (PRRT) can target these cells.

Chemotherapy: is a type of treatment that uses stronger drugs to kill fasting growing cells.

The estimate of how a disease will affect you long-term is called prognosis. Each person is different and prognosis will depend on many factors, such as:

• Where the tumor is in your body
• If the cancer has spread to other parts of your body
• How much of the tumor was taken out during surgery

If you want information on your prognosis, it is important to talk to your doctor.

Doctors estimate carcinoid tumor survival rates by how groups of people with carcinoid tumor have done in the past. In children, because there are so few cases of carcinoid tumor, these rates may not be very accurate.

The prognosis for children and young adults who have surgery to remove the tumor have a very good prognosis. Some studies show the 5-year survival rate for children and young adults with bronchial carcinoid tumor that has been removed is over 90%. Prognosis for people whose carcinoid tumor has spread to other parts of the body may be lower.