What is the treatment of Neuroendocrine Tumors ?
General approach to treatment
The main factors in selecting treatment options for a neuroendocrine tumor are:
- Its size and location
- Whether it has spread to lymph nodes, liver, bones, or other organs
- Whether you have any other serious medical conditions
- Whether the tumor is causing bothersome symptoms
Surgery remains the best option of treatment for Neuroendocrine tumors. Unlike other cancers these tumors tend to grow slowly but occasional tumors can be aggressive as well. Unlike other organ cancers if tumor shows signs of spread (metastases), it can still be treated aggressively by removal or destruction of the tumors. Example a surgeon may not give too much hope for a person with Stomach Cancer that has spread to the liver but a person with neuroendocrine tumor that has spread to the liver will still be treated aggressively and may even get cured.
The options for neuroendocrine tumors that have spread locally or distantly are more complex. Because most neuroendocrine tumors grow very slowly and some do not cause any symptoms, completely removing all metastatic tumors may not always be needed. In some patients, surgery to remove all visible cancer is the best option. This is particularly true if removing most of the cancer will reduce the level of hormone-like substances causing symptoms.
Several types of operations may be used to treat neuroendocrine tumors. Some of these remove the primary tumor (where the cancer started), while others remove or destroy cancer spread (metastases) in other organs such as RFA (radiofrequency ablation).
Several medicines can help control the symptoms of carcinoid syndrome / hormonal symptoms in patients with metastatic neuroendocrine cancers.
Octreotide (Sandostatin®) is an agent chemically related to a natural hormone, somatostatin. It is very helpful in treating flushing, diarrhea, and wheezing from carcinoid syndrome. While this drug rarely shrinks carcinoid tumors, it may slow or stop their growth. Although this is not curative, it can prolong life.
This drug comes in a short-acting version that is given 2 to 4 times a day. It is also available as a long-acting injection that needs to be given only once a month (Sandostatin LAR®), which may help patients more than the short-acting version.. A newer drug, pasireotide, is currently being studied.
Chemotherapy uses anti-cancer drugs that are injected into a vein or a muscle or taken by mouth to kill cancer cells. These drugs enter the bloodstream and reach all areas of the body, making this treatment useful for some types of cancers that have spread to other organs.
Unfortunately, not many neuroendocrine tumors respond to chemotherapy. Because of this, chemotherapy generally is used only for tumors that have spread to other organs, are causing severe symptoms, and have not responded to other medicines. Tumors may be treated with more than one drug, although it’s not clear that this is any more effective than using a single drug. New chemotherapy drugs and combinations of drugs are being studied.
Interferons are natural substances that normally activate the body’s immune system. They also slow the growth of tumor cells. Interferon-alfa is sometimes helpful in shrinking or slowing the growth of metastatic neuroendocrine cancers and improving symptoms of carcinoid syndrome. Its usefulness is sometimes limited by its flu-like side effects, which may be severe. The drug is given by injection.
Intra-arterial therapy and chemoembolization.
Normally, chemotherapy drugs enter the bloodstream and can travel throughout the body. When carcinoid cancer has spread to the liver, it is sometimes treated by directly injecting the chemotherapy drug into the hepatic artery, which supplies blood to parts of the liver. This exposes the liver tumors to high doses of the drug but limits exposing the rest of the body. Sometimes the chemotherapy drug is injected together with a material that plugs up the artery (an approach called chemoembolization). When the arteries leading to them are blocked, the tumors become starved for nutrients and oxygen and many die off.
At first, even tiny meals may make you feel uncomfortably full. You will need to eat very small amounts very often at first. Then, gradually increase the amounts and then the time between meals. At first, you may find you need to eat every hour or so in order to get enough nutrition.
There is no restriction on the type of food you eat after a pancreas surgery and you should be able to eat all that you did before surgery. Fizzy drinks can make you feel full – it is probably best not to drink with meals at all, as any liquid will fill you up.
Try keeping a food diary if you are having problems you think are related to your diet. Take a small notebook and draw a line down the centre of each page. Write down what you eat and when on the left of the page. Write down any symptoms you get and when on the other side of the page. After a few days, you may be able to spot which foods cause which symptoms.
Some people need to take tablets to help digest fat and proteins, and some people develop diabetes, which may require treatment.
Several newer types of drugs, known as targeted therapies, are now being studied for use against neuroendocrine tumors and cancers. These drugs are designed to attack some specific aspect of cancer cells. Bevacizumab (Avastin®), for example, attacks a tumor’s blood supply. It is already being used against some types of cancer and is being studied for these tumors. Other targeted therapies block the molecules that increase the growth of cancer cells. Some of these (such as erlotinib, temsirolimus, sorafenib) are used in other types of cancer and are now being tested against carcinoids.
Radionuclide scans, such as the Octreoscan, can be helpful in finding neuroendocrine cancers because they use substances that are attracted to neuroendocrine cells. These substances are attached to slightly radioactive elements so that they can be detected with special cameras. Using higher doses of Octreotide delivers more radiation to the tumor cells and is used in very few centres to treat neuroendocrine tumors and cancers. Doctors are now using octreotide labelled with a radioactive form of the element Lutetium called the Lutetium octreotide therapy or PRRT (peptide receptor radiotherapy). When injected into the body, the octreotide homes in on the tumor cells, where the radiation given off by the Lutetium could kill the tumor cells. So far, results have been promising, but this treatment is not easily available at all centres.