Treatment of neuroendocrine cancer
Cancer treatment is given by cancer specialists (oncologists). Some specialize in surgery, some in radiation therapy and others in chemotherapy (drugs). These doctors work with the person with cancer to decide on a treatment plan.
Treatment plans are designed to meet the unique needs of each person with cancer. Treatment decisions for neuroendocrine cancer are based on:
- hormone status
A team approach forms the current basis of treatment in various highly specialized centres in Canada and around the world. A combination of different treatments is tailored to give the most effective results for each individual person with a diagnosis of neuroendocrine cancer.
An internal medicine specialist, usually an endocrinologist, medical oncologist, surgeon, pathologist, primary nurse, nuclear medicine physician, advanced practice nurse, interventional radiologist, cardiologist, and cardiac surgeon may form the neuroendocrine team in these specialized centres.
Treatment for neuroendocrine cancer is used to:
- remove or reduce the tumour mass
- control hormone secretions and their adverse effects
- manage any complications caused by the tumour or hormone secretions. For example, too much serotonin released by a neuroendocrine tumour or carcinoma causes carcinoid syndrome, including flushing, diarrhea, asthma-like symptoms (bronchoconstriction) and palpitations. Too much serotonin is often associated with damage to the heart, which requires active treatment to improve and preserve cardiac function.
The following are treatment options for neuroendocrine cancer.
The goal of surgery is to completely remove a localized neuroendocrine carcinoma.
In advanced neuroendocrine carcinomas, surgery is used to remove as much of the tumour as possible (debulking). This helps reduce tumour load and symptoms, which in turn prolongs survival.
Interventional radiology techniques are less invasive because they use image guidance. For people with liver metastases, using embolizationembolizationA procedure that blocks or slows down the blood supply to tissues or an organ. to block the blood flow to the tumour can reduce tumour mass and improve quality of life and survival. Embolization of liver metastasis, with or without adding cytotoxic drugs (chemoembolizationchemoembolizationA procedure to reduce or block the main blood supply to a tumour and deliver chemotherapy drugs directly to the tumour.), is a treatment option for some people.
Somatostatin is a hormone produced by neuroendocrine cells in the brain and digestive system. It suppresses the release of growth hormone, thyroid-stimulating hormone and gastrointestinal hormones. Somatostatin has a very short half-life of about 2–3 minutes. Octreotide and lanreotide are synthetic substitutes with the same action (congeners) as somatostatin, but they have a longer half-life of about 90 minutes. They are used to treat gastrointestinal and pancreatic functional (hormone-producing) neuroendocrine tumours and carcinomas by preventing them from producing hormones.
Immunotherapy with interferon is a type of biological therapy that stimulates the body’s immune system to fight cancer. Interferon alfa (Intron A, Roferon A) is most widely used in cancer treatment.
Sunitinib (Sutent) and everolimus (Afinitor) are other types of biological therapy that may be used to treat pancreatic neuroendocrine tumours. Sunitinib blocks the action of tyrosine kinase, which helps send signals inside cancer cells that tell the cells to grow. Evermolimus blocks cells from making the mTOR protein, which can trigger cancer cells to grow and new blood vessels to form.
External beam radiotherapy has limited use in the treatment of neuroendocrine carcinomas. It is used to treat brain and bone metastases.
Targeted radiotherapy or systemic radiotherapy with radiolabelled somatostatin analogues is effective in treating some neuroendocrine carcinomas. In systemic radiation therapy, a radioactive material (a radioactive isotope) is taken by mouth or is injected into the body. It travels throughout the body and is absorbed by cancer cells. The same radioisotopes are used to diagnose neuroendocrine tumours, but they are given in higher doses when used as a treatment. Special safety precautions are taken after systemic radiation therapy. A person may also be given amino acids and potassium iodide to protect other organs (liver and thyroid) from the effects of the radioactive isotopes. Commonly used radioactive isotopes are:
- indium-111 pentetreotide
- I-131 metaiodobenzylguanidine (MIBG)
Chemotherapy is not part of first-line treatment for neuroendocrine carcinomas. Surgery and other treatments that reduce the bulk of tumours, as well as targeted therapies, are more effective than chemotherapy. Chemotherapy is generally used in aggressive late-stage disease. Neuroendocrine carcinomas are usually treated with chemotherapy regimens that include streptozocin (Zanosar) and 5-fluorouracil (Adrucil, 5-FU).
Chemotherapy may be given to specific areas of the body as a regional therapy. Chemotherapy using hepatic artery infusion (HAI) delivers drugs directly to the liver to treat liver metastasis.
Supportive therapy manages the symptoms or complications caused by the cancer, but it does not actively treat the cancer.
Functional (hormone-producing) neuroendocrine tumours or carcinomas require treatment to manage symptoms caused by the overproduction of hormones.
Supportive therapy is also tailored to manage specific complications of some neuroendocrine carcinomas, such as intestinal obstruction or heart disease.
Clinical trials investigate better ways to prevent, detect and treat cancer. For more information, go to clinical trials.