Daily or monthly injections of somastostatin analogues are available to control some of the unpleasant symptoms caused by the tumours. Somatostatin analogues are synthetic versions of somatostatin, a naturally occurring hormone produced in the brain and digestive tract that inhibits the release of several other hormones and chemicals from our internal organs.
Injections of these analogues can stop the overproduction of hormones that cause symptoms such as flushing and diarrhoea.
Recent clinical studies have shown that somatostatin analogues can also be used to help stabilise (stop the growth for a period of time) some low grade NETs, and further studies are ongoing to see how well these drugs work on different types of NET.
Targeted Peptide Receptor Radionuclide Therapy PRRT
These treatments are sometimes referred to as ‘magic bullet’ therapies. The treatments are based on using different radiolabelled peptides which target receptors on the tumour surface. In PRRT for neuroendocrine tumours, the radionuclides commonly used are indium111, lutetium-177 and yttrium-90. The basis for which treatment is suitable for which patient is the diagnostic tracer imaging. To decide whether this therapy is suitable, you will be asked to take an Octreotide, PET or MIBG scan as described in the diagnosis section. The results of these scans will indicate whether or not you have the correct receptors present and whether this sort of therapy would be an option.
SIRT stands for Selective Internal Radiation Therapy. It is a new way of using radiotherapy to treat liver metastases which cannot be removed with surgery. The doctor inserts a thin tube called a catheter into the hepatic artery. This is the main artery which supplies blood to the liver. They then send tiny beads called microspheres down the catheter and these get stuck in the small blood vessels around the tumour. The microspheres contain a radioactive substance which give a dose of radiation to the tumour. The microspheres are also called SIR-spheres and the radioactive substance is called yttrium 90.
If the tumour has spread to the liver, you may be offered hepatic artery embolisation (HAE). In this procedure, a catheter is placed in the groin and then threaded up to the hepatic artery that supplies blood to the tumours in the liver. Tiny particles called embospheres (or microspheres) are injected through the catheter into the artery. These particles swell and block the blood supply to the tumour, which can cause the tumour to shrink or even die. This treatment can also be combined with systemic
treatments in some patients where the tumour has spread. It is a procedure that would be carried out by a specialist called an interventional radiologist. The patient would be sedated for the treatment. Sometimes this embolisation process is combined with chemotherapy (called HACE (Hepatic Artery Chemoembolisation) or TACE (Transcatheter Arterial Chemoembolisation) or radiotherapy (RMT or SIRT).
Radiofrequency Ablation (RFA)
This may be used when a patient has relatively few secondary tumours (metastases) in the liver. A needle is inserted into the centre of the tumour and a current is applied to generate heat which kills the tumour
This may be an option for NET patients especially those with pancreatic, bronchial or high grade NETs. Not all NETs respond equally to chemotherapy, therefore careful selection of patients is imperative so as to maximise the chance of response and avoid unnecessary toxicity. Many chemotherapy treatments involve intravenous drugs, however there are now also oral chemotherapy agents and your NET doctor will discuss the most appropriate option with you. The histology of the tumour i.e. how it looks down the microscope after biopsy or operation, may help determine the type of treatment you receive. Chemotherapy may sometimes be recommended after surgery (adjuvant therapy). You may be asked to be involved with clinical trials currently underway which are looking into the different combinations of chemotherapy agents that are most appropriate for different types of NET cancer.
Sutent is a medication that comes in capsule form. It is mainly used in patients with pancreatic neuroendocrine tumours. It works mainly by blocking a process called angiogenesis. Angiogenesis is the process of making new blood vessels. Tumours need a good blood supply to grow and Sutent helps stop that process. The drug comes under an umbrella group of drugs known as tyrosine kinase inhibitors
Affinitor is another medication for patients with pancreatic neuroendocrine tumours. It also comes in a capsule form and is a type of drug that interferes with the process of new cancer growth. The drug comes under an umbrella group of drugs known as mTOR inhibitors. Clinical trials are running to look at the effectiveness of this medication in other NET types either alone or in combination with other NET medications.
Clinical trials are medical research trials involving patients. They are carried out to try to find new and better treatments. Carrying out clinical trials is the only sure way to find out if a new approach to cancer care is better than the standard treatments currently available.can find out more about current NET trials at: www.netpatientfoundation.org/category/patient-resources/research/
No treatment or watchful waiting may be suitable for you if your NET is not currently causing you any symptoms or problems and the tumour(s) are stable. You may also have other health conditions that would make the NET treatment inadvisable.
The follow-up intervals are highly variable depending on the clinical situation, functionality (whether any syndrome is present), stage, grade and time since diagnosis. Intervals may vary, but generally follow-up should be tailored to individual needs and is usually every 3-6 months initially.