Currently available treatment options

Treatment can reduce the number and size of NETs as well as some of the symptoms caused by them. Your doctor will discuss the best treatment options for you based on the type and stage of the NET, as well as your medical history.

Cancer and its treatments can cause side effects in some patients. You may tolerate your treatment well, but knowing what is expected, and when to let your doctor know if you experience anything unexpected, is essential. Your care team can help you manage side effects and help you feel more comfortable. Your care team might make changes to your treatment, prescribe specific medications or provide advice on adjusting your diet and general lifestyle.  

Below is information on some of the available therapeutic options and common side effects of each specific treatment. Remember that these are all just potential side effects, and the experience of each patient can be different.

Surgical management

Patients with NETs often have surgery to remove the tumors, especially at early stages^1,2. The goal of surgery depends on the type of NET, its location in the body and size, as well as whether it has spread from the primary site.

• Curative surgery: if an early-stage tumor can be removed entirely and intact with a perimeter of clear, healthy tissue, the surgery can potentially cure the cancer, and no other treatment may be required.

• Palliative surgery: if the tumor has spread or is too large to remove altogether, surgery to reduce the tumor size may help relieve symptoms and improve quality of life if the tumor affects other organs or produces excessive amounts of hormones. Palliative surgery may be offered in combination with different types of treatments that might be more effective once the tumor size is reduced.

General side effects of surgery

Many factors determine how well you will recover from surgery: your general health, the type and complexity of the surgery, possible complications during surgery and so on. Your doctor/care team should explain the potential side effects of any procedure you might need. Common side effects of surgery include pain where the surgery took place, bleeding or fluid leaking from the wound, swelling and bruising, infection, and fatigue.

Medical management

• Somatostatin analogs (SSAs),
  SSAs are variants of naturally occurring somatostatin, a hormone produced in the brain and digestive tract which regulates the release of several other hormones and chemicals from internal organs. Injections of SSAs can stop the overproduction of hormones (like serotonin) that cause symptoms such as facial flushing and diarrhea. There is evidence that SSAs can also slow down the growth rate of some NETs of the digestive tract³. SSAs are given either daily (short-acting) or monthly (long-acting) as an injection.

General side effects of SSAs

The side effects of SSAs can be relatively mild, are usually temporary, and can be resolved. They may include loss of appetite, nausea, feeling bloated, stomach pain, fatigue, diarrhea (rare), soreness at the injection site, and changes in heart rate. You might also have altered (raised or lowered) blood sugar levels. If you have diabetes, you may need to check your blood sugar levels more often, and you might need to increase or decrease your medication. Your doctor can help you manage any changes in your medication dose/schedule.

While uncommon, receiving SSAs over many months may cause gallstones, so you might have an ultrasound scan of your gallbladder before you start treatment and then every 6 to 12 months during treatment.

• Chemotherapy may be an option for some types of NET and may sometimes be recommended after surgery for high-grade NETs. Chemotherapy works either by stopping or slowing the growth of cancer cells, which grow and divide quickly.

  Chemotherapy is usually given intravenously (IV) in a hospital setting but does not normally require you to stay overnight. There are also oral chemotherapy agents that your doctor may consider. You and your doctor should discuss the best option(s) for you.

General side effects of chemotherapy

There are many chemotherapy agents, and every patient reacts to them differently. Your doctor should discuss potential side effects with you. Some common ones include fatigue (this can carry on for several months after your treatment ends), nausea, hair loss, increased risk of infection, weight loss, diarrhea and constipation, dry skin and skin rashes, and numbness or tingling in the hands and feet.

• Targeted molecular therapies specifically attack cancer cells with minimal damage to healthy cells. They can have different mechanisms of action and affect how cancer cells grow, divide and/or spread. For example, tyrosine kinase inhibitors may be used in pancreatic NETs to block a process known as angiogenesis (in which the tumors create new blood vessels to maintain a good blood supply to support their growth).

General side effects of targeted molecular therapies

Each individual targeted molecular therapy has different side effects. Some possible general side effects may include mouth ulcers, diarrhea, constipation, fatigue, nausea, loss of appetite and weight loss.

Nuclear medicine

Targeted radiopharmaceutical therapy (RPT), sometimes referred to as peptide receptor radionuclide therapy (PRRT) or radioligand therapy (RLT), is used to treat NETs when other types of treatment, such as surgery and chemotherapy, are not suitable or are ineffective (due to the size, location or number of tumors). As the name suggests, targeted RPT combines a radioactive component with a targeting molecule that is strongly attracted to somatostain receptors (which are found on the surface of most NETs). When RPT is considered, a diagnostic scan is performed to confirm the presences of somatostatin receptors.

RPTs are given as an IV injection. Once in the bloodstream, the targeting molecules locate and bind to the tumor cells and the radioactive component releases a small amount of radiation next to or into the tumor. The radiation damages the cancer cells and prevents the tumor from growing.

General side effects of RPT

Side effects of RPT include: pain after treatment, nausea, vomiting, diarrhea, increased liver enzymes (for example, bilirubin), fatigue, some hair loss (not baldness), increased risk of infection, risk of carcinoid syndrome flare and minor changes in blood production.

Less common side effects include bone marrow or kidney toxicity. To protect your kidneys, you may receive an infusion of amino acids.⁴

Liver-directed therapies

You may be offered different types of interventional radiology procedures if your tumor has spread to the liver. These minimally invasive procedures are performed by radiologists under local anesthetic and/or sedation.

• Hepatic arterial embolization (HAE): with the help of x-ray imaging, a radiologist will use an artery in the groin area to direct a catheter into the main blood vessel of the liver (the hepatic artery) and into the artery that supplies blood to the NET(s) in the liver. Tiny particles called microspheres are then injected through the catheter to block the blood supply to the tumors. This prevents the tumors from getting the oxygen and nutrients they need to grow and can cause them to shrink or even die out.

General side effects of HAE

Potential side effects of HAE include discomfort or pain in the right side of your abdomen and right shoulder, bruising or bleeding at the treatment site, fever (antibiotics may be given before and after the procedure to reduce the risk of infection), flu-like symptoms, nausea and vomiting. Very rarely, embolization can cause the liver and kidneys to stop working, so you will have regular blood tests to monitor these organs.

• Radiofrequency ablation (RFA): using ultrasound or CT guidance, a needle is inserted through the abdominal wall into the tumor, where an electrical current (radiofrequency energy) is delivered – producing high temperatures that destroy the cancer cells.

General side effects of RFA

Potential side effects of RFA include discomfort or pain at the treatment site, bruising or bleeding where the treatment took place, blood clotting in the vessels nearest the area of treatment, fever (antibiotics may be given before and after the procedure to reduce the risk of infection), flu-like symptoms, abscess, inflammation of surrounding tissue (such as pancreatitis if you have had RFA to treat a pNET). Additionally, ablation procedures in the lungs can cause a lung collapse. Your doctor should review any potential side effects with you prior to any procedure.