Neuroendocrine tumour (NET) treatment

Here we look at the common treatment options for neuroendocrine tumours (NETs).

Learn more about:

• Making treatment decisions
• Your health care team
• Treatment options
• Surgery
• Somatostatin analogues (SSAs)
• Surgery for non-functional pancreatic NETs
• Theranostics – peptide receptor radionuclide therapy (PRRT)
• Chemotherapy
• Targeted therapy
• Treatment for liver tumours
• External beam radiation therapy
• Joining a clinical trial

Making treatment decisions

It can be difficult to know which treatment is best for you. It is important that you speak with a NET specialist team before making decisions. Ask them to give you a clear plan of your treatment options, including information about side effects. Some people prefer to seek several opinions before feeling confident to go ahead with treatment. If you are confused or want to check anything, ask your specialist questions. This will make sure you have all the information you need to make decisions that you are comfortable with.

You may have to attend many appointments. It’s a good idea to take someone with you. They will be able to listen, ask questions and remember what the doctor says. It may help to take a list of questions with you, take notes or ask the doctor if you can record the discussion (many mobile phones have a recording function or you can use the CAN.recall app).

Your health care team

You will be cared for by a multi-disciplinary team of health professionals during your treatment for NETs. These may include a:

• surgeon
• medical oncologist (to prescribe and coordinate a course of systemic therapy which includes chemotherapy)
• radiation oncologist (to prescribe and coordinate a course of radiation therapy)
• nuclear medicine specialist
• gastroenterologist
• endocrinologist
• lung physician
• nurse and allied health professionals such as a dietitian
• social worker
• psychologist or counsellor
• physiotherapist
• occupational therapist.

For neuroblastoma, the team will include childhood cancer specialists, including a paediatric oncologist.

Treatment options

Discussion with your doctor will help you decide on the best treatment for your tumour depending on:

• the type of NET you have, including if it is functional (hormone producing) and the symptoms you have
• where it is in your body
• the grade of the tumour, if known
• whether or not the NET has spread (stage of disease)
• your age, fitness and general health
• your preferences.

The main treatment options for NETs include surgery, chemotherapy, targeted therapy, theranostics – peptide receptor radionuclide therapy (PRRT) and drug therapy (to control any symptoms caused by extra hormones). Merkel cell carcinoma may also be treated using radiotherapy. Treatments can be given alone, in combination or one after the other.

This is called multi-modality treatment. If the NET is slow-growing and not causing any symptoms you may not need immediate treatment.

Surgery

Surgery is the main treatment for most types of NETs, especially for people with early-stage disease who are in otherwise good health. Surgery usually involves removing the cancer and some healthy tissue around the cancer to ensure the tumour is completely removed. It is important to have your surgery in a specialist centre with surgical and anaesthetic experience with NETs.

The type of operation depends on the size of the tumour and where it is located. For Merkel cell carcinoma the surgery may also involve removing the lymph nodes close to the tumour.

Surgery for early-stage NETs is often given with the aim of cure, although there can also be benefits from removing areas of tumour, even if the cancer has spread (e.g. to reduce the risk of bowel obstruction in small bowel NETs). However, there are risks and potential complications involved in surgery. Your surgeon will discuss the type of operation you may need and the benefits and impacts of surgery.

For more on this, see our general section on Surgery.

Somatostatin analogues (SSAs)

The body produces a hormone called somatostatin, which controls how organs release several other hormones. SSAs are medicines that are similar to somatostatin. SSAs can slow down or prevent tumour growth, as well as slow down the release of hormones from NETs. They may be used to help control symptoms associated with carcinoid syndrome such as facial flushing and diarrhoea.

The main SSAs used in Australia are octreotide LAR and lanreotide. These are generally given as monthly injections, but may be given more often if required.

Surgery for non-functional pancreatic NETs

Early-stage

As with more common types of pancreatic cancer, surgeries include:

Advanced

Surgery can be used to treat blockages caused by the tumour and to reduce the size of the tumour.

More information on these surgeries is available in our information on surgery to remove pancreatic cancer and inserting a stent, and from NeuroEndocrine Cancer Australia.

Theranostics – peptide receptor radionuclide therapy (PRRT)

PRRT, a form of radiation treatment, may be offered to some people with NETs. You will have PET scans first to assess if you are suitable for this treatment. The PET scans will show whether your tumours take up the radiation. This treatment uses a radioactive compound bound together with a small molecule that attaches strongly to NET cells. This allows high doses of radiation to be delivered to specific sites of tumours wherever they have spread throughout the body.

The most common form of PRRT is 177 Lu-Dota-octreotate (LuTate) therapy. PRRT is available only in certain specialised treatment centres in each state (generally in metropolitan areas). You will usually see a nuclear medicine specialist and a medical oncologist.

You may have a dose of chemotherapy in tablet form before PRRT as a combined treatment. PRRT is injected into your vein via a cannula, with a session lasting around four hours. Most people have four sessions about 8–12 weeks apart. Re-treatment with PRRT is possible in selected cases. A video on PRRT is available at NeuroEndocrine Cancer Australia.

Chemotherapy

Chemotherapy (sometimes just called “chemo”) is the use of drugs to kill or slow the growth of cancer cells. You may have one chemotherapy drug, or a combination of drugs. This is because different drugs can destroy or shrink cancer cells in different ways. Your treatment will depend on the grade and type of tumour you have. Chemotherapy is more often given to treat high-grade NETs. Your medical oncologist will discuss your options with you.

Chemotherapy is given through a drip into a vein (intravenously) or as a tablet that is swallowed. Chemotherapy is commonly given in treatment cycles which may be daily, weekly or monthly. For example, one cycle may last three weeks where you have the drug over a few hours, followed by a rest period before starting another cycle. The length of the cycle and number of cycles depends on the chemotherapy drugs being given.

For more on this, see our general section on Chemotherapy.

Targeted therapy

Targeted therapy uses drugs that work in a different way to chemotherapy drugs. While chemotherapy drugs affect all rapidly dividing cells and kill cancer cells, targeted therapy drugs attack specific molecules within cells and work by blocking cell growth. People with advanced pancreatic NETs may be offered targeted therapies such as sunitinib (Sutent) and everolimus (Afinitor) to slow the growth of the tumour. Everolimus may also be used to treat advanced gastro-intestinal, pancreatic and lung NETs. These drugs are in capsules that you swallow.

For more on this, see our general section on Targeted therapy.

Treatment for liver tumours

NETs, particularly gastro-intestinal and pancreatic, often spread to the liver. The tumours in the liver are called metastases.

Treatments to control these liver lesions may include:

Radiofrequency ablation (RFA) and microwave ablation – Using an ultrasound or CT scan, a needle is inserted through the abdomen into the liver tumour. The needle sends out radio waves or microwaves that produce heat and destroy the cancer cells.

Transarterial chemoembolisation (TACE) – In this procedure, a catheter is inserted into the hepatic artery, which supplies blood to the liver. A chemotherapy drug together with tiny particles (called microspheres) is released into the artery, which blocks the flow of blood into the tumour. This may cause the tumour to shrink. The procedure is performed by an interventional radiologist. Sometimes the injection may involve using microspheres alone without the chemotherapy component, called transarterial embolization (TAE).

Selective internal radiation therapy (SIRT) – Also known as radioembolisation, this is done by an interventional radiologist. The radiologist inserts a catheter into the liver’s main artery and then delivers tiny radioactive beads (SIR-spheres) to the liver through the catheter. The beads give a direct dose of radiation to the tumour.

PRRT can also be used to treat liver lesions in selected cases.

External beam radiation therapy

Radiation therapy (also known as radiotherapy) uses high energy rays to destroy cancer cells, where the radiation comes from a machine outside the body. NETs may be treated with external beam radiation therapy in selected cases, depending on the location of tumours and your symptoms.

It may be used:

• if the cancer can’t be removed with surgery
• if the cancer has spread to other parts of the body
• after surgery, to destroy any remaining cancer cells and stop the cancer coming back (such as for Merkel cell carcinoma).

Radiation therapy can shrink the cancer down to a smaller size. This may help to relieve symptoms such as pain. Sometimes chemotherapy is given as well as radiation therapy, for example to treat lung NETs.

Radiation therapy does not hurt and is usually given in small doses over a period of time to minimise side effects.

For more on this, see our general section on Radiation therapy.

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