Neuroendocrine Tumors: Types of Treatment

Approved by the Cancer.Net Editorial Board, 05/2022

ON THIS PAGE: You will learn about the different types of treatments doctors use for people with a neuroendocrine tumor (NET). Use the menu to see other pages.

This section explains the types of treatments, also known as therapies, that are the standard of care for a NET. “Standard of care” means the best treatments known and are usually based on strong evidence from past clinical trials. When making treatment plan decisions, you are also encouraged to discuss with your doctor whether clinical trials are an option. A clinical trial is a research study that tests a new approach to treatment. Doctors learn through clinical trials whether a new treatment is safe, effective, and possibly better than the standard treatment. Clinical trials can test a new drug, a new combination of standard treatments, or new doses of standard drugs or other treatments. Clinical trials are an option for all stages of cancer. Your doctor can help you consider all your treatment options. Learn more about clinical trials in the About Clinical Trials and Latest Research sections of this guide.

How a NET is treated

In cancer care, different types of doctors often work together to create a patient’s overall treatment plan that combines different types of treatments. This is called a multidisciplinary team and is especially important for people with a NET. Cancer care teams include a variety of other health care professionals, such as physician assistants, nurse practitioners, oncology nurses, social workers, pharmacists, counselors, dietitians, and others.

Treatment options and recommendations depend on several factors, including:

  • The primary site, which is where the NET began

  • Whether the tumor is functional, meaning whether it releases hormones and causes related symptoms

  • Stage, which is where the tumor is located in the body

  • Grade and degree of differentiation, which is how fast the cells are dividing

  • Pace of growth

  • Somatostatin receptor status, determined by whether the tumor is bright on 68Ga DOTATATE PET scan

  • Possible side effects

  • The patient’s preferences and overall health

Take time to learn about all of your treatment options and be sure to ask questions about things that are unclear. Talk with your doctor about the goals of each treatment and what you can expect while receiving the treatment. These types of talks are called “shared decision-making.” Shared decision-making is when you and your doctors work together to choose treatments that fit the goals of your care. Shared decision-making is particularly important for a NET because there are different treatment options. Learn more about making treatment decisions.

The common types of treatments used for a NET are described below. Your care plan also includes treatment for symptoms and side effects, an important part of cancer care.

Visit the individual section for a specific type of NET for more information about treatment options (see the Introduction for a complete list).

Active surveillance

Sometimes, active surveillance may be recommended. This approach is also called watchful waiting or watch-and-wait. It is used most often for someone with a low-grade NET that may grow slowly and not spread or cause problems for many months or years. If the tumor shows signs of growing or spreading, the doctor will talk with you about starting active treatment, such as surgery and/or therapies using medications (see below).

With active surveillance, your health and the tumor are closely monitored with regular tests, which may include:

  • Imaging tests, usually computed tomography (CT) scans or sometimes magnetic resonance imaging (MRI) scans (see Diagnosis)

  • Blood tests

  • Physical examinations and evaluation of new symptoms

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Surgery

Surgery is the removal of the tumor and some surrounding healthy tissue during an operation. A surgical oncologist is a doctor who specializes in cancer surgery. Completely removing the entire tumor is the standard treatment, when possible.

Most localized NETs are successfully treated with surgery alone. The surgeon will usually remove some tissue surrounding the tumor, called a margin, in an effort to leave no traces of cancer in the body.

When completely removing the tumor is not possible, "debulking surgery" is sometimes recommended. Debulking surgery removes as much of the tumor as possible and may provide some relief from symptoms, but it generally does not cure a NET. Deciding whether debulking surgery is the best treatment choice should be done after discussion with multiple specialists in different aspects of medical care.

People who have developed carcinoid syndrome are at risk of experiencing a carcinoid crisis during surgery (see Symptoms and Signs). To avoid major complications from a carcinoid crisis, the anesthesiology team must be fully aware of this risk before surgery, so they can have treatment on hand to control the symptoms. Intravenous octreotide is usually given before surgery to prevent carcinoid crisis.

Before surgery, talk with your health care team about the possible side effects from the specific surgery you will have. Learn more about the basics of cancer surgery.

If removing a NET using surgery is not possible, it is called an “inoperable” tumor. In these situations, the doctor will recommend another treatment plan.

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Therapies using medication

The treatment plan may include medications to destroy cancer cells. Medication may be given through the bloodstream to reach cancer cells throughout the body. When a drug is given this way, it is called systemic therapy. Medication may also be given locally, which is when the medication is applied directly to the cancer or kept in a single part of the body.

This treatment is generally prescribed by a medical oncologist, a doctor who specializes in treating cancer with medication.

Medications can be given through an intravenous (IV) tube placed into a vein using a needle, in a pill or capsule that is swallowed (orally), or intramuscular (IM) injections. If you are given oral medications, be sure to ask your health care team about how to safely store and handle them.

Depending on the type of NET, medications that may be used include:

  • Somatostatin analogs

  • Targeted therapy

  • Peptide receptor radionuclide therapy (PRRT)

  • Chemotherapy

  • Immunotherapy

Each of these types of therapies are discussed below in more detail. A person may receive 1 type of medication at a time or a combination of medications given at the same time. They can also be given as part of a treatment plan that includes surgery and/or radiation therapy.

The medications used to treat NETs are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications.

It is also important to let your doctor know if you are taking any other prescription or over-the-counter medications or supplements. Herbs, supplements, and other drugs can interact with medications for NET, causing unwanted side effects or reduced effectiveness. Learn more about your prescriptions by using searchable drug databases.

Somatostatin analogs

Somatostatin is a hormone in the body that controls the release of several other hormones, such as insulin and glucagon. Somatostatin analogs are drugs that are similar to somatostatin and are used to control the symptoms created by the hormone-like substances released by a NET. They may also slow the growth of a NET, although they do not generally shrink the tumors.

There are 2 somatostatin analogs used to treat NETs, octreotide (Sandostatin) and lanreotide (Somatuline Depot). Octreotide is available in 2 forms: short-acting is given under the skin (subcutaneously) and long-acting is given as an intramuscular injection. Lanreotide is given as a long-acting subcutaneous injection. The most common side effects are high blood sugars (hyperglycemia), the development of gallstones, and mild digestive system upset, such as bloating and nausea. Talk with your health care team about what you can expect and how side effects will be managed.

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Targeted therapy

Targeted therapy is a treatment that targets the tumor’s specific genes, proteins, or the tissue environment that contributes to tumor growth and survival. This type of treatment blocks the growth and spread of tumor cells and limits damage to healthy cells.

Not all tumors have the same targets. To find the most effective treatment, your doctor may run tests to identify the genes, proteins, and other factors in your tumor. This helps doctors better match each patient with the most effective treatment whenever possible. In addition, research studies continue to find out more about specific molecular targets and new treatments directed at them. Learn more about the basics of targeted treatments.

Everolimus (Afinitor) is a targeted therapy approved by the U.S. Food and Drug Administration (FDA) for the treatment of advanced NETs of the gastrointestinal (GI) tract, lung, and pancreas. This drug targets a protein called mTOR that is important for cell growth and survival. This drug can help slow down the growth of these tumors in some patients, but it does not usually shrink tumors. Side effects include mouth sores, lowering of blood counts, and fatigue.

Sunitinib (Sutent) is a targeted therapy that targets a protein called VEGF. VEGF is important in angiogenesis, which is the process of making new blood vessels. Because a tumor needs the nutrients delivered by blood vessels to grow and spread, the goal of anti-angiogenesis therapies like sunitinib is to “starve” the tumor. It is approved by the FDA for the treatment of advanced pancreatic NETs. Common side effects associated with this drug include diarrhea, nausea, vomiting, fatigue, and high blood pressure.

Other targeted therapies for NETs are being researched in clinical trials. They include drugs that interfere with new blood vessel formation or with specific survival pathways of cancer cells.

Talk with your doctor about possible side effects for a specific medication and how they can be managed.

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Peptide receptor radionuclide therapy (PRRT)

In 2018, the FDA approved a treatment called 177Lu-dotatate (Lutathera) for advanced GI tract NETs and pancreas NETs. As a combined category, GI tract NETs and pancreas NETs are sometimes referred to as "GEP NETs." This treatment is also being studied for the treatment of other NETs. It is a radioactive drug that works by binding to a cell’s somatostatin receptor, which may be present on certain tumors. After binding to the receptor, the drug enters the cell, allowing radiation to damage the tumor cells. The broader term to describe this treatment is peptide receptor radionuclide therapy (PRRT).

Common side effects include low levels of white blood cells, high enzyme levels in some organs, nausea and vomiting, and fatigue. A rare, but serious side effect, is the development of blood cancer after the treatment. Talk with your doctor about ways these can be avoided or managed.

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Chemotherapy

Chemotherapy is the use of drugs to destroy cancer cells, usually by keeping the cancer cells from growing, dividing, and making more cells.

A chemotherapy regimen, or schedule, usually consists of a specific number of cycles given over a set period of time. A patient may receive 1 drug at a time or a combination of different drugs given at the same time. Chemotherapy for a NET may be used when the tumor has spread from where it started to other organs, if the tumor is causing severe symptoms, or if hormonal therapies or targeted therapies are no longer working. Chemotherapy may be used alone or in combination with other treatments.

The side effects of chemotherapy depend on the individual and the dose used, but they can include fatigue, risk of infection, nausea and vomiting, hair loss, loss of appetite, and diarrhea. Not all chemotherapies cause hair loss. These side effects usually go away after treatment is finished.

Learn more about the basics of chemotherapy.

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Immunotherapy

Immunotherapy uses the body's natural defenses to fight cancer by improving your immune system’s ability to attack cancer cells. Interferon alfa-2b (Intron A) is a type of immunotherapy that has been used in the past to treat NETs. Interferon helps the body’s immune system work better and can lessen diarrhea and flushing. It may also shrink tumors. This is treatment is not used very often nowadays due to newer FDA-approved treatments.

Talk with your doctor about possible side effects for the immunotherapy recommended for you. Learn more about the basics of immunotherapy.

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Radiation therapy

Radiation therapy is the use of high-energy x-rays or other particles to destroy tumor cells. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist.

The most common type of radiation treatment for a NET is called external-beam radiation therapy, which is radiation given from a machine outside the body. It is most often used as part of supportive care to relieve symptoms, such as pain, caused by cancer that has spread to the bone and other areas of the body (see “Physical, emotional, and social effects of a NET” below).

Patients receiving radiation therapy may experience fatigue during treatment, and the treated area may become red and dry. Radiation therapy to the chest or neck may cause a dry, sore throat or a dry cough. Some patients have shortness of breath during radiation therapy. Most side effects go away after the treatment is finished. Learn more about the basics of radiation therapy.

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Liver-directed treatment

If cancer has spread to the liver, the treatments below may be used. These procedures are usually performed by an experienced interventional radiologist and may require an overnight hospital stay. Side effects include pain around the liver, fever, and higher levels of liver enzymes as measured by blood tests for a few days or weeks after treatment.

Radiofrequency ablation (RFA). RFA destroys a tumor by heating it with an electric current. It is usually used for small liver metastases and does not work well on larger tumors.

Hepatic artery embolization. This procedure blocks the tumor’s blood supply by sealing off the blood vessels leading to the tumor. If embolization is done by itself, it is called bland embolization. When combined with chemotherapy, it is called chemoembolization. When it is combined with radiation therapy, it is called radioembolization.

It is not yet clear if one form of embolization treatment is more effective than the other. Although there are possible long-term side effects of radioembolization, so most centers that treat NETs select other treatment options. These treatments are usually used for people with metastatic disease that mostly affects the liver, in particular those who have symptoms caused by the size of the tumor or by hormones produced by the tumor.

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Physical, emotional, and social effects of a NET

A NET and its treatment cause physical symptoms and side effects, as well as emotional, social, and financial effects. Managing all of these effects is called palliative care or supportive care. It is an important part of your care that is included along with treatments intended to slow, stop, or eliminate the tumor.

Supportive care focuses on improving how you feel during treatment by managing symptoms and supporting patients and their families with other, non-medical needs. Any person, regardless of age or type and stage of tumor, may receive this type of care. And it often works best when it is started right after a diagnosis. People who receive supportive care along with treatment for the tumor often have less severe symptoms, better quality of life, and report that they are more satisfied with treatment.

Supportive treatments vary widely and often include medication, nutritional changes, relaxation techniques, emotional and spiritual support, and other therapies. You may also receive palliative treatments similar to those meant to get rid of the tumor, such as chemotherapy, surgery, or radiation therapy.

For some people, such as those with lung disease, heart disease, or other specific medical conditions, surgery cannot successfully treat the tumor. In these cases, palliative surgery to relieve symptoms may be helpful. Palliative surgery is often used together with radiation therapy.

Before treatment begins, talk with your doctor about the goals of each treatment in the recommended treatment plan. You should also talk about the possible side effects of the specific treatment plan and palliative care options. Many patients also benefit from talking with a social worker and participating in support groups. Ask your doctor about these resources, too.

During treatment, your health care team may ask you to answer questions about your symptoms and side effects and to describe each problem. Be sure to tell the health care team if you are experiencing a problem. This helps the health care team treat any symptoms and side effects as quickly as possible. It can also help prevent more serious problems in the future.

Learn more about importance of tracking side effects in another part of this guide. Learn more about palliative care in a separate section of this website.

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Metastatic NET

If a NET spreads to another part in the body from where it started, doctors call it metastatic cancer. If this happens, it is a good idea to talk with doctors who have experience in treating it. Doctors can have different opinions about the best standard treatment plan. Clinical trials might also be an option. Learn more about getting a second opinion before starting treatment, so you are comfortable with your chosen treatment plan.

Your treatment plan may include a combination of the types of treatment described above. Surgery may be used to relieve symptoms rather than eliminate the cancer at this stage. If distant metastases are not causing symptoms, surgery may not be needed. If the person develops carcinoid syndrome, surgery may be recommended to remove as much cancer as possible. Systemic treatments using medications and radiation therapy may also be offered to help relieve symptoms.

Participation in clinical trials is encouraged. Supportive care will also be important to help relieve symptoms and side effects.

For many people, a diagnosis of metastatic cancer is very stressful and difficult. You and your family are encouraged to talk about how you feel with doctors, nurses, social workers, or other members of your health care team. It may also be helpful to talk with other patients, such as through a support group or other peer support program.

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Remission and the chance of recurrence

A remission is when a NET cannot be detected in the body and there are no symptoms. This may also be called having “no evidence of disease” or NED.

A remission may be temporary or permanent. This uncertainty causes many people to worry that the tumor will come back. While many remissions are permanent, it is important to talk with your doctor about the possibility of the NET returning. Understanding your risk of recurrence and the treatment options may help you feel more prepared if the tumor does return. Learn more about coping with the fear of recurrence.

If the NET returns after the original treatment, it is called a recurrent NET. It may come back in the same place (called a local recurrence), nearby (regional recurrence), or in another place (distant recurrence).

If a recurrence happens, a new cycle of testing will begin again to learn as much as possible about it. After this testing is done, you and your doctor will talk about the treatment options. Often the treatment plan will include the treatments described above, such as surgery, chemotherapy, and radiation therapy, but they may be used in a different combination or given at a different pace. Your doctor may suggest clinical trials that are studying new ways to treat a recurrent NET. Whichever treatment plan you choose, palliative care will be important for relieving symptoms and side effects.

People with a recurrent tumor sometimes experience emotions such as disbelief or fear. You are encouraged to talk with your health care team about these feelings and ask about support services to help you cope. Learn more about dealing with a recurrence.

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If treatment does not work

Recovery from a NET is not always possible. If the tumor cannot be cured or controlled, the disease may be called advanced and incurable.

This diagnosis is stressful, and for some people, an advanced NET is difficult to discuss. However, it is important to have open and honest conversations with your health care team to express your feelings, preferences, and concerns. The health care team has special skills, experience, and knowledge to support patients and their families and is there to help. Making sure a person is physically comfortable, free from pain, and emotionally supported is extremely important.

People who have advanced disease and who are expected to live less than 6 months may want to consider hospice care. Hospice care is designed to provide the best possible quality of life for people who are near the end of life. You and your family are encouraged to talk with the health care team about hospice care options, which include hospice care at home, a special hospice center, or other health care locations. Nursing care and special equipment can make staying at home a workable option for many families. Learn more about advanced cancer care planning.

After the death of a loved one, many people need support to help them cope with the loss. Learn more about grief and loss.

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The next section in this guide is About Clinical Trials. It offers more information about research studies that are focused on finding better ways to care for people with a NET. Use the menu to choose a different section to read in this guide.