Neuroendocrine Tumour

Neuroendocrine tumours are rare cancers that develop in specialized cells throughout the body, most commonly affecting the digestive system, lungs, and pancreas. While these tumours can be challenging to diagnose and manage, advances in treatment are helping more people live for years with this condition.

Table of contents

• What are neuroendocrine tumours?
• Types of neuroendocrine tumours
• How common are neuroendocrine tumours?
• Symptoms of neuroendocrine tumours
• Causes and risk factors
• How neuroendocrine tumours are diagnosed
• Treatment options
• Living with neuroendocrine tumours

What are neuroendocrine tumours?

Neuroendocrine tumours are cancers that start in neuroendocrine cells, which are specialized cells found throughout the body. These cells have traits similar to both nerve cells, which send and receive signals from the brain, and endocrine cells, which make hormones that control various body functions^[1].

These tumours can develop anywhere in the body, but they most commonly occur in the digestive system, lungs, and pancreas. Most neuroendocrine tumours are malignant, meaning they are cancerous^[2].

Neuroendocrine tumours vary greatly in how they behave. Some grow slowly over many years, while others grow more quickly. Understanding the specific characteristics of each tumour helps doctors determine the most effective treatment approach^[1].

Types of neuroendocrine tumours

There are several ways to classify neuroendocrine tumours. One important distinction is based on whether they produce hormones^[2]:

• Functional neuroendocrine tumours release hormones that can cause symptoms related to excess hormone levels in the body
• Non-functional neuroendocrine tumours don’t release hormones or don’t release enough to cause symptoms, though they can still cause problems if they affect an organ

Neuroendocrine tumours are also classified based on where they develop in the body^[2]:

• Gastrointestinal neuroendocrine tumours are the most common type. They usually start in the intestines, rectum, or appendix. These tumours used to be called carcinoid tumours
• Lung neuroendocrine tumours start in the lungs or the tubes that carry air from the windpipe to the lungs. These are the second most common type
• Pancreatic neuroendocrine tumours start in the pancreas and are the third most common type

Less commonly, neuroendocrine tumours can develop in the thyroid gland, parathyroid glands, pituitary gland, adrenal glands, or thymus^[2].

How common are neuroendocrine tumours?

Neuroendocrine tumours are rare, affecting about 6 in every 100,000 people worldwide. However, more people are being diagnosed with these tumours in recent years, likely because diagnostic tests have improved and can identify them more quickly^[2].

Although anyone can develop a neuroendocrine tumour, they are rare in children, teenagers, and young adults. Most people diagnosed with these tumours are between the ages of 50 and 60^[2].

Symptoms of neuroendocrine tumours

Often, neuroendocrine tumours don’t cause symptoms until the tumour begins to affect an organ. When symptoms do appear, they vary depending on where the tumour is located^[2].

Common symptoms may include^[2]:

• Fatigue
• Stomach pain
• Diarrhea
• Nausea and vomiting
• Shortness of breath
• Coughing, sometimes with blood

It’s important to remember that having these symptoms doesn’t always mean you have cancer. Many other conditions can cause similar symptoms. However, if you’re experiencing symptoms that don’t improve, it’s important to talk to a healthcare provider^[2].

Some neuroendocrine tumours produce large amounts of hormones, which can cause a group of symptoms called carcinoid syndrome. This may include flushing of the skin and severe diarrhea^[1].

Causes and risk factors

Neuroendocrine tumours form when neuroendocrine cells begin to divide and multiply uncontrollably. Over time, these cells become tumours that can affect the organs where they are located. Researchers don’t know exactly what triggers this abnormal cell growth^[2].

Researchers have linked neuroendocrine tumours to rare inherited conditions that involve changes in certain genes. Your risk of developing a neuroendocrine tumour increases if you have one of these conditions, particularly Multiple Endocrine Neoplasia Type 1 (MEN1), which is the most common cancer syndrome associated with neuroendocrine tumours^[2].

How neuroendocrine tumours are diagnosed

Diagnosing a neuroendocrine tumour often starts with a physical examination. A healthcare professional may check your body for signs of cancer, such as swollen lymph nodes or signs that a tumour is producing excess hormones^[10].

Several tests may be used to diagnose neuroendocrine tumours^[10]:

• Blood and urine tests can look for signs of excess hormones that some neuroendocrine tumours produce
• Imaging tests create pictures of the inside of the body to show the tumour’s location and size. These may include ultrasound, CT scans, MRI scans, or special PET scans that can detect neuroendocrine tumour cells
• Biopsy involves removing a sample of tissue for testing in a laboratory. Tests can show whether cancer cells are present and provide information about the type of tumour

Treatment options

Treatment for neuroendocrine tumours depends on several factors, including the type of tumour, its location, whether it produces excess hormones, how aggressive it is, and whether it has spread to other parts of the body^[1].

Common treatment options include^[13][15]:

• Surgery is the main treatment for neuroendocrine tumours when possible. It may be performed to remove the tumour completely or to reduce its size and relieve symptoms
• Somatostatin analogues are medicines that reduce and control high hormone levels in functional tumours. These are often given as monthly injections and are usually the first treatment for most slow or intermediate-growing neuroendocrine tumours
• Chemotherapy uses anti-cancer drugs to destroy cancer cells. It’s commonly used for fast-growing neuroendocrine tumours or when tumours have spread to other parts of the body
• Targeted therapy uses drugs that target specific characteristics of cancer cells to help control tumour growth
• Peptide receptor radionuclide therapy (PRRT) is a specialized treatment that uses a radioactive substance attached to a hormone-like molecule. This targets and destroys neuroendocrine tumour cells throughout the body
• Radiotherapy uses radiation to destroy cancer cells
• Liver-directed therapies are special treatments used when neuroendocrine tumours have spread to the liver

For some slow-growing neuroendocrine tumours, treatment may not be needed right away. Instead, doctors monitor the cancer with regular tests and begin treatment only when necessary^[13].

Living with neuroendocrine tumours

Living with a neuroendocrine tumour can be challenging, as many of these cancers are chronic conditions that require ongoing management. However, with proper treatment and support, many people live for years with neuroendocrine tumours^[2].

Diet and nutrition play an important role in managing symptoms and maintaining overall health. Certain foods or eating habits may trigger symptoms, particularly in people with functional tumours. Some tips that may help include^[20]:

• Eating smaller, more frequent meals
• Avoiding fatty, greasy, or highly spicy foods
• Choosing whole, natural foods over processed ones high in salt
• Avoiding alcohol, aged cheeses, chocolate, and fermented foods if you have carcinoid syndrome

Staying physically active through regular exercise, such as walking, can help maintain strength and energy during treatment. It’s also important to avoid smoking if you smoke^[21].

Managing the emotional challenges of living with cancer is just as important as physical care. Many people find it helpful to join support groups for people with neuroendocrine tumours, talk to a counselor, or practice stress-reduction techniques like meditation^[19].

Regular follow-up appointments with your healthcare team are essential for monitoring your condition and adjusting treatment as needed^[13].