Treatments for NETs
Treatments for neuroendocrine cancers vary from person to person and may be one or more of the following:
“Watch & Wait”
This is done by regular monitoring through clinic review, bloods and scans to assess how well treatment is working or in periods between treatments (which may be months/years).
Surveillance is used to check your cancer and general health for any signs of change that may mean that a treatment might need to be considered. All treatments have possible side-effects, therefore, it is important to know when treatment may be helpful for you or not.
Surgery is usually the first choice of treatment when it is possible to remove the tumour completely. This is the case when the tumour is contained (or localised) in one area. If the tumour has already spread (or metastiasized) to other parts of the body, the pros and cons of surgery have to be considered carefully.
This is when the cancer has not spread outside the organ or area where it first started. If the tumour can be removed whole and intact with a surrounding margin of normal healthy tissue, then the surgery might be curative and no other treatment may be necessary. A follow-up plan will need to be put into place after surgery.
If a NET has already spread, or become too large to remove completely, then surgery may be considered in specific situations. Surgery may be performed if the NET is causing symptoms by pressing on other organs, or by releasing hormones. In this instance surgery aims to reduce the symptoms by removing (or ‘debulking’) a large chunk of the tumour, or bypassing the part of the disease that is causing the problems.
This can occur when an area of tumour is critically placed close to an important structure that might become blocked as the tumour grows, such as a blood vessel or the main bile duct, or the bowel. Even though this will not cure the disease, it can prevent immediate problems by removing tumours from key areas, before the vital structure has been damaged or blocked.
This involves heart valve replacement and may be required for patients with carcinoid heart disease.
Treatments targeting NETs throughout the body
Somatostatin analogues are synthetic versions of somatostatin, a naturally occurring hormone produced in the brain and digestive tract that acts like an ‘off’ switch for some of the normal processes in the gut. Injections of these analogues can stop the overproduction or secretion of hormones that cause symptoms such as flushing, wheezing and diarrhoea and therefore improve quality of life. Injections are also used to help slow tumour growth in some slower growing “well differentiated” NETs.
Chemotherapy regimens involve either intravenous drugs (this means given through a drip), or oral drugs or tablets and your oncologist will discuss the most appropriate option with you. The proliferative index of the tumour (the Ki-67 mentioned earlier) may help the oncologist decide the type of treatment you receive. Chemotherapy is not useful for slow growing NETs.
Fast growing NETs are often treated with intravenous chemotherapy as a first line treatment.
Chemotherapy may also be used to increase tumour cell sensitivity to radiation therapies.
Chemotherapies associated with NETs are Carboplatin & etoposide; Capecitabine & Temazolomide
Targeted Molecular Therapies
Can be given orally (in tablets) or intravenously (through a vein) to slow tumour growth or try to reduce tumour size. Drugs such as Sunitinib and Everolimus are used for Pancreatic NETs. Currently there is no public funding for these in New Zealand.
Interferon: This is a naturally occurring substance that is produced by the body’s immune system. Taking extra injections of interferon activates the body’s immune system and is used to treat some patients with NETs. In some patients it is given on its own, but more often it is given as a combination therapy with a somatostatin analogue. This is only used in specific situations because of the side effects that some people experience.
Peptide receptor radionuclide therapy
May also be called “Radioligand Therapy” – uses targeted radiation to treat NETs.
This treatment works in a similar way to an Gallium or Ga68 scan(add link to scan), except that a higher dose of radioactive tracer is attached to the octreotide. This high dose is enough to kill the tumour cell that the octreotide binds to.
To decide whether this therapy is suitable, you have to first have had the Ga68 PET scan. Intermediate and aggressive NET patients will also need a FDG PET scan. The results of these scans will indicate whether or not your NET has enough receptors present on tumour cells, and whether this sort of therapy would be an option.
In September 2020 PRRT launched in New Zealand for the first time, thanks to years of Unicorn Foundation NZ advocacy.
To help patients understand what this treatment involves, Unicorn Foundation NZ has worked with Auckland District Health Board to produce a patient guide.
Treatments that target liver metastases
For people with NETs that are mostly sitting in the liver, it makes sense to target the liver directly. The three main ways of doing this are surgery, embolization (blocking the blood supply to parts of the liver) or ablation (directly targeting individual tumour spots in the liver).
embolisation (HAE) &
In this procedure, a catheter is placed in a blood vessel in the groin (femoral artery), to gain access into the arterial system. A catheter is then threaded up to the hepatic artery that supplies blood to the liver and the branches supplying the tumour are able to be targeted. Tiny particles (or microspheres) are injected through the catheter into these arteries. The particles block the blood supply to the tumour, which can cause it to shrink or even die. This procedure is done by a specialist called an interventional radiologist. Patients are either sedated or under a general anaesthetic for treatment.
A hepatic artery chemoembolisation (HACE) is the same as HAE, but the microspheres are loaded with chemotherapy.
Selective internal radiation therapy (SIRT)
This treatment is similar to HAE, but the microspheres are loaded with radiation. The spheres once lodged into the tumour then cause localised radiation damage. To ensure that patients are suitable for SIRT they require a planning angiogram, where a test dose is delivered. Currently SIRT is not funded in the public sector in NZ.
Used when a patient has relatively few secondary tumours (metastases). A needle is inserted into the centre of each tumour, and thermal energy (heat) is then delivered into the tumour to kill the cells. It is very useful in treating small tumours that are not touching major blood vessels.
Other types of treatments for NETs
Is sometimes given after surgery, or as a primary treatment, to kill any cancer cells that might remain there. It may also be used for cancer that has spread beyond the primary site, in particular if disease has spread to the bones – here it is used to help control growth of any spread and alleviate bone pain. It is targeted at one specific area or site.
Clinical research and safe new treatment development is essential to provide best care for those with Neuroendocrine Cancer – we need to know that treatments not only work but work safely. There are several phases of trial therapy and each trial will have specific criteria in regards to patient suitability – this can be discussed with your clinical team. You do not have take part in a trial – participation is voluntary.
Managing symptoms, including pain, is an important part of total care – and therefore occurs throughout care, not just at ‘end-of-life’. Symptom control or ‘palliation’ refers to what is used to alleviate or reduce the impact your cancer, other health issues and /or treatments may be having on you and your physical and mental health. It can include anything from simple medication and / or a combination of some of the treatments mentioned above to counselling and practical support.
Did you know it takes on average 5 - 7 years for NETs to be correctly diagnosed in a patient?