Neuroendocrine Tumors

About Neuroendocrine Tumours

Neuroendocrine tumours (NET) are fairly rare tumours that develop from specialized cells of the body’s neuroendocrine system. These cells have traits of both hormone-producing endocrine cells and nerve cells. (Neuro = nerve tissue, (Endocrine = hormonal system). These types of cells are found throughout the body’s organs and help control many of the body’s functions. Therefore, these tumours can arise in many different organ systems, for example, the pancreas, adrenal glands, gastrointestinal system (including stomach, large and small bowel), lung,  thyroid gland and even from the skin. 

Due to the multiple different types of neuroendocrine tumours, the presentation, symptoms and course of the disease are variable and dependent on many factors. These include, but are not limited to:  

  • where the tumour originates from,
  • if the tumour excretes hormones or other biochemical substances (if the  tumour is functional or non-functional)
  • how fast the tumour grows

The WHO (world health organisation) has developed a grading system based on how fast the tumour is expected to grow (how fast cell turnover happens). This grading can only be done by evaluating a tissue sample under the microscope and determining how fast the cells are undergoing change. There is referred to as the Ki-67. If a Ki-67 is not done the mitotic rate is also used at times. 

Grade 1: <2% (well-differentiated neuroendocrine tumour)

Grade 2: 2- 20 % (well-differentiated neuroendocrine tumour)

Grade 3: (neuro-endocrine carcinoma)

Well-differentiated (20 – 50%)

Poorly differentiated (>50%)

This classification is important because it will also determine what therapy would be best for the treatment of your type of cancer. 

You can also click on this link to learn more about the different Stages and Grades.

What is a tumour?

A tumour begins when the DNA of healthy cells is damaged, causing the cells to change and grow out of control, forming a mass. A tumour can be cancerous (malignant) or non-cancerous (benign). 

A cancerous tumour can grow and spread to other parts of the body if it is not found early and treated. This is called metastases. 

A non-cancerous tumour can grow and cause local symptoms (eg pain or pressure on the surrounding tissues), but it does not spread to other parts of the body, and it usually does not have any systematic effects. When the benign tumour is removed the symptoms usually resolve. 

Neuroendocrine tumours are malignant tumours

For specific information on the different types of tumours please go to the international resources link and click on the type of cancer you would like more detail.