What are neuroendocrine tumours?
What are neuroendocrine tumours?
Neuroendocrine tumours – also called NETs – are a type of tumour (or abnormal mass of cells) that can form in the cells of the neuroendocrine system.1
The neuroendocrine system is a network of glands and nerve cells found throughout the body. These glands and cells make hormones and release them into the bloodstream, helping to control normal bodily functions, such as digesting food.1
The type of cells found in the neuroendocrine system are called neuroendocrine cells. While these cells can be found throughout the body, they mainly occur in the gastrointestinal tract (including the large and small bowels), the pancreas, and the lungs.1
In 2022 NETs were the 7th most diagnosed cancer in Australia, with an estimated 5400 Australians diagnosed with a NET.*2 Most new NETs are found in people aged over 40 years.1
*Data from Australian Institute of Health and Welfare, October 2022
NETs are usually described by where in the body the abnormal cells come from. The most common locations where NETs develop are the digestive tract and the lungs.1,3
NETs can also be described in the following ways:1,3
- How fast the tumour is growing – ranging from low grade (slow growing) to high grade (fast growing)
- Whether extra hormones are being produced – functional tumours produce extra hormones that can cause certain symptoms in the body; non-functional tumours don’t produce extra hormones
Different types of NETs include:1,3
- Gastrointestinal NETs – these can start in different areas of the large bowel or small bowel, and represent about 54% of all NETs
- Pancreatic NETs – start in the endocrine cells of the pancreas, and account for about 7% of all NETs; most are non-functional
- Lung NETs – develop in the lungs and represent about 25% of all NETs
- Merkel cell carcinoma – a fast-growing NET that involves the Merkel cells present in the top layer of the skin
- Neuroblastoma – usually starts in the adrenal glands (located on top of each kidney) and affects immature or developing nerve cells in children; more common in children under 5 years of age
The exact cause of most NETs is not known. Some risk factors for developing NETs may include:1,3
- Genetic factors – NETs are associated with some rare inherited diseases
- Pre-existing conditions – peptic ulcers may increase risk for NETs in the digestive tract; diabetes may increase risk for developing pancreatic NETs
- Age – most NETs affect people aged over 40 years
- Sex – NETs appear to be slightly more common in men than in women, and slightly higher again in black African men
Most NETs grow slowly over years, but some can grow quickly and spread to other parts of the body. During the early stages, NETs may not cause symptoms, or they may only cause general nonspecific symptoms that can commonly occur with other illnesses, such as tiredness or loss of appetite.1,3
The types of symptoms caused by NETs will be different depending on the location of the NET and whether the NET is producing hormones.1,3
Type of NET
Merkel cell carcinoma
*These are not all the possible symptoms of NETs, and not all patients with NETs will experience all the symptoms listed.
Your doctor will discuss your specific symptoms with you. Different tests are used to diagnose NETs depending on those symptoms and where in the body the tumours are thought to be.1,3
Tests used to assess for NETs include:1,3
- Blood tests – usually include a full blood count to count the number of different types of blood cells and tests for different tumour markers
- Urine tests – to measure levels of a chemical called serotonin that can be produced by NETs
- Endoscopy – uses a camera inserted down the throat into the stomach or into the anus and large bowel to view the gut; this test is performed under sedation to avoid discomfort
- Bronchoscopy – uses a thin tube with a light and lens inserted through the mouth or nose to view the lungs; this test is performed under sedation to avoid discomfort
- Computed tomography (CT scan) – takes three-dimensional pictures of several organs at the same time; used to help doctors plan surgery, if required
- Magnetic resonance imaging (MRI scan) – records detailed cross-sectional pictures (“slices”) of the inside of the body; used to show the extent of any tumours
- Positron emission tomography (PET scan) – produces three-dimensional colour images that show where any cancers are in the body
- Biopsy – removes a small sample of tissue from the affected area for closer examination; biopsies are performed using local or general anaesthetic
- Echocardiogram – uses an ultrasound to examine heart valves than can sometimes be affected by NETs
Treatment options for NETs
Neuroendocrine tumours are associated with very different presentations and symptoms, so treatment options are varied and need to be tailored to each individual patient.
The treatment plan that your doctors recommend will depend on the type, location, and size of the NETs, and how advanced the cancer has become, as well as your overall health and personal preferences. You may have more than one type of treatment, which may be given in different orders or combinations depending on your situation. 1,3
Treatments that may be used for NETs include:1,3
- Surgery – removes tumours and some surrounding healthy tissue
- Hormone therapy – uses a specific hormone to help slow tumour growth and the overproduction of hormones
- Chemotherapy – uses medications to kill cancer cells or reduce their growth and spread
- Radiation therapy – uses radiation to destroy cancer cells in the affected area
- Targeted therapies – uses medications designed to target specific features of cancer cells to stop their growth and spread
- Theranostics – uses a PET scan to identify targets for selective drug delivery
Your treatment team at GenesisCare
Your treatment with GenesisCare
Patients who are receiving treatment for NETs are usually cared for by a multidisciplinary team of healthcare professionals. Depending on the type and location of NETs, your treatment team may include surgical oncologists, medical oncologists, and radiation oncologists, as well as doctors who specialise in disorders of the digestive tract (gastroenterologist), endocrine system (endocrinologist), or respiratory system (respiratory physician).1
A NET diagnosis can be life changing, and you may feel many different emotions. You may experience disbelief, sadness, anger, and loneliness.1 At GenesisCare, we aim to deliver a personalised care experience provided by a team of compassionate healthcare professionals. Your care team aim to know your name as quickly as possible, and to understand who you are as a person.
Your multidisciplinary care team will include oncologists and nurses, and they are here to support you before, during, and after your NET treatment. As part of your care, we may offer you access to a range of Allied Health support services, and depending on your location these may include a psychologist, exercise physiologist, physiotherapist, and dietitian – all tailored to support your need.1 A member of your treatment team will discuss the most suitable options with you.
Other NET information, resources, and support services are available to assist you during your cancer journey. These include:
Cancer Council Australia
Tel: 13 11 20
Neuroendocrine Cancer Australia (previously the Unicorn Foundation)
Tel: 1300 287 363
Carcinoid Cancer Foundation
Tel: 0419 871 975
Australasian Gastrointestinal Trials Group
Tel: 1300 666 769
This website is provided for information purposes only. Nothing on this website is intended to be used as medical advice, or to diagnose, treat, cure, or prevent any disease. It should not be used as a substitute for your own health professional's advice.
Any medical procedure or treatment involving the use of radiation carries risks, including skin irritation and associated pain. Before proceeding with treatment, you should discuss the risks and benefits of the treatment with an appropriately qualified health practitioner. Individual treatment outcomes and experiences will vary.
- Cancer Council. Understanding neuroendocrine tumours. Cancer Information Fact Sheet. 2021. Available: https://www.cancer.org.au/cancer-information/types-of-cancer/rare-cancers/neuroendocrine-tumours (accessed July 2023).
- Cancer Australia. Neuroendocrine tumours. Available from: https://www.canceraustralia.gov.au/cancer-types/neuroendocrine-tumours/statistics (accessed July 2023).
- Australasian Gastrointestinal Trials Group. Neuroendocrine tumours. Available: https://gicancer.org.au/cancer/neuroendocrine-tumours/ (accessed July 2023).