Hormone therapy for neuroendocrine cancer

Hormones are substances that control some body functions, including how cells act and grow. Hormone therapy adds, blocks or removes hormones to slow or stop the growth of cancer cells that need hormones to grow. Hormone levels can be changed or blocked by drugs, surgery or radiation therapy.

Hormone therapy is often used to treat neuroendocrine tumours (NETs). It’s typically not used to treat neuroendocrine carcinomas (NECs). If you have hormone therapy, your healthcare team will use what they know about the cancer and about your health to plan your treatment.

Hormone therapy may be the only treatment you have or it may be used along with other cancer treatments. You may have hormone therapy to:

• slow down and control the growth of a NET
• treat symptoms caused by a tumour making too much of a hormone, including the symptoms of carcinoid syndrome

Carcinoid syndrome is a group of symptoms that include flushing, wheezing, fast heart rate, weight loss and diarrhea. It’s caused by a NET that releases a large amount of hormones (including serotonin) and other chemicals into the body. The type of hormone released depends on where the NET starts in the body.

Somatostatin analogues are drugs that lower the amount of hormones made and released by NETs.

They are mainly used to control symptoms of carcinoid syndrome. If you don’t have symptoms of carcinoid syndrome (asymptomatic) but you do have increased levels of 5-HIAA, you may be given somatostatin analogues to help reduce the risk of heart problems or control heart problems (carcinoid heart disease).

Somatostatin analogues are also used to slow down and control the growth of advanced or metastatic cancer when surgery can’t be done. The tumour may be functional or non-functional. Functional tumours make more hormones than we normally need and cause symptoms. Non-functional tumours make normal amounts of hormone that usually don’t cause any symptoms.

The most common somatostatin analogue used is octreotide (Sandostatin). It’s available in a long-acting form (octreotide LAR) or a short-acting form. Another somatostatin analogue that may be used is lanreotide (Somatuline Autogel). It’s in a long-acting form like octreotide LAR.

Octreotide LAR or lanreotide is standard treatment for the long-term control of symptoms and tumour growth. Octreotide LAR is injected into a muscle (intramuscular). Lanreotide is injected into the deep layer under the skin but not into the muscle (deep subcutaneous). The drug is given once a month. It’s usually taken for as long as it works. It may be taken for the rest of your life.

The short-acting form of octreotide is injected right under the skin (subcutaneous) and is given several times a day. Before having it as a regular treatment, you’ll likely have to try it for a short period to see if your body can cope with it. It’s also used before surgery or other treatments to prevent and manage carcinoid crisis. Carcinoid crisis is a severe and life-threatening problem that causes flushing of the skin, low blood pressure, difficulty breathing and an irregular heartbeat.

Side effects of hormone therapy will depend mainly on the type of hormone therapy, the dose of a drug or combination of drugs, and your overall health. Tell your healthcare team if you have side effects that you think are from hormone therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Octreotide and lanreotide may cause these side effects:

• gallbladder problems, including gallstones
• diarrhea
• fatty stools (steatorrhea) that are light coloured, bulky and float in the toilet
• pain in the abdomen
• nausea and vomiting
• high or low blood sugar (glucose) levels
• dizziness
• blurred vision

Find out more about hormone therapy and side effects of hormone therapy. To make the decisions that are right for you, ask your healthcare team questions about hormone therapy.

Details on specific drugs change regularly. Find out more about sources of drug information and where to get details on specific drugs.