Drugs Used to Treat Pancreatic Neuroendocrine Tumors

The drugs used to treat pancreatic neuroendocrine tumors (NETs) tend to be different from those used to treat exocrine pancreatic cancer (the most common type of pancreatic cancer. These drugs are used mainly when the tumor can’t be removed with surgery.

Somatostatin analogs

Drugs that are similar to somatostatin, a natural hormone in the body, can be very helpful for some patients with pancreatic NETs. These drugs stop tumors from releasing hormones into the bloodstream, which can often relieve symptoms and help patients feel better. They also seem to help slow the growth of some tumors.

These drugs can be expected to help anyone with a tumor that can be seen on somatostatin receptor scintigraphy (see “Imaging tests” in Tests for Pancreatic Cancer). They can help reduce diarrhea in patients with VIPomas, glucagonomas, and somatostatinomas, and can also help the rash of glucagonomas.

The somatostatin analogs currently available include:

  • Octreotide (Sandostatin): The standard version of octreotide is short-acting and is injected 2 to 4 times a day. There is also a long-acting form of the drug (called Sandostatin LAR Depot) that only needs to be given once a month, which may help patients more than the short-acting version.
  • Lanreotide (Somatuline Depot): This is a newer somatostatin analog, which is injected under the skin about once a month. It has been shown to help slow the growth of pancreatic NETs.
  • Pasireotide (Signifor, Signifor LAR): Another newer somatostatin, this drug is injected either twice a day or about once a month. Pasireotide is being studied for use in pancreatic NETs, although the other drugs are used more often.

Possible side effects

The main side effects of these drugs are pain at the site of the injection, and rarely, stomach cramps, nausea, vomiting, headaches, dizziness, and fatigue. These drugs can also cause sludge to build up in the gallbladder, which can lead to gallstones. They can also make the body resistant to the action of insulin, which can raise blood sugar levels and make pre-existing diabetes harder to control. These drugs are not often used to treat insulinomas, because the effects on the release of other hormones can cause worse problems with blood sugars.

Chemotherapy for pancreatic neuroendocrine tumors

Chemotherapy (chemo) uses anti-cancer drugs injected into a vein or taken by mouth. Chemo is most often used to treat NETs that are large or growing quickly and are causing symptoms. When chemo is used it often includes a combination of 2 or more drugs.

The most commonly used drugs for pancreatic NETs include:

  • Doxorubicin (Adriamycin) or liposomal doxorubicin (Doxil)
  • Streptozocin
  • Fluorouracil (5-FU)
  • Dacarbazine (DTIC)
  • Temozolomide (Temodar)
  • Capecitabine (Xeloda)
  • Oxaliplatin (Eloxatin)

For poorly differentiated (high-grade) NETs (sometimes called neuroendocrine carcinomas), a combination of a platinum drug (either cisplatin or carboplatin) plus etoposide is often used.

To learn more about chemo (including possible side effects), see the Chemotherapy section of our website.

Targeted therapy for pancreatic neuroendocrine tumors

Targeted drugs work differently from standard chemo drugs. They attack specific changes in tumor cells that help them grow. Some targeted drugs can be helpful in treating advanced pancreatic NETs.

Sunitinib (Sutent) attacks new blood vessel growth and other targets that help cancer cells grow. In advanced pancreatic NETs, it has been shown to slow tumor growth and help patients live longer. This drug is taken as pills once a day. The most common side effects are nausea, diarrhea, changes in skin or hair color, mouth sores, weakness, and low blood cell counts. Other possible effects include tiredness, high blood pressure, heart problems, bleeding, hand-foot syndrome (redness, pain, and skin peeling of the palms of the hands and the soles of the feet), and low thyroid hormone levels.

Everolimus (Afinitor) works by blocking a cell protein known as mTOR, which normally helps cells grow and divide. This drug has been shown to slow tumor growth, but it’s not yet clear if it helps patients live longer. Everolimus is a pill taken once a day. Common side effects of this drug include mouth sores, infections, nausea, loss of appetite, diarrhea, skin rash, feeling tired or weak, fluid buildup (usually in the legs), and increases in blood sugar and cholesterol levels. A less common but serious side effect is damage to the lungs, which can cause shortness of breath or other problems.

Other drugs that treat pancreatic neuroendocrine tumors

Other types of drugs are sometimes useful in treating people with pancreatic NETs as well.

Diazoxide: This drug can block insulin release from the pancreas. It can be used to prevent low blood sugar (hypoglycemia) in patients with insulinomas. This drug is often used before surgery, to make the operation safer for the patient.

Proton pump inhibitors: These drugs block acid secretion from the stomach. They are often very helpful in preventing ulcers in patients with gastrinomas, although they might need to be taken in higher than usual doses. Examples of these drugs include omeprazole (Prilosec), esomeprazole (Nexium), and lansoprazole (Prevacid).

Systemic Radiation Therapy

For adults with somatostatin (a type of hormone) receptor-positive pancreatic neuroendocrine tumors, a radioactive drug, called Lutathera (lutetium Lu 177 dotatate), has been approved for treatment. Lutathera, also called a radiopharmaceutical, works by attaching to the somatostatin receptor (protein), which is part of the cancer cell, allowing radiation to enter the cell and cause damage. It can be given alone or in combination with octreotide.

Common side effects of Lutathera include low levels of white blood cells, high levels of enzymes in certain organs, nausea and vomiting, high levels of blood sugar, and low levels of potassium in the blood.

Serious side effects of Lutathera include low levels of blood cells, development of certain blood or bone marrow cancers, kidney damage, liver damage, abnormal levels of hormones in the body, and infertility. Women who are pregnant or might become pregnant should be advised that Lutathera can cause harm to a developing fetus.

Lutathera is given intravenously and does expose those taking it to radiation. Other patients, medical personnel, and household members should limit their radiation exposure in accordance with radiation safety practices.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: March 14, 2016 Last Revised: May 31, 2016

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