Grades of Neuroendocrine (NET) Cancers

Grades of Neuroendocrine (NET) Cancers

Your doctor might classify your NET as a grade according to the World Health Organization (WHO) grading system. Grading describes how tumour cells look under a microscope. It shows how abnormal the cells are and can give an idea of how quickly the tumour may develop. The grade is determined by both the mitotic count and Ki-67, which are markers of how fast the tumour cells grow and divide. 

Identifying the grade of your NET helps you and your doctor create an appropriate treatment plan.

• Grade 1 (low-grade tumor): These cells divide at a low rate and therefore grow slowly.
• Grade 2 (intermediate-grade tumor): These cells divide at an intermediate rate.
• Grade 3 (high-grade tumor): These cells divide at a fast rate and therefore grow quickly.

NETs are also usually divided into three groups:

• Well differentiated – the cells look like normal cells and are usually slow-growing.
• Moderately differentiated – the cells look more abnormal.
• Poorly differentiated – the cells look very abnormal. They are likely to grow more quickly and spread.

How are grades different to stages?

The grade focuses on how the tumour cells look under a microscope, as well as how they’re dividing and at what rate. 

The stage of a NET describes its size and whether it has spread beyond its original site.

Your NET may fall under one of these stages:

• Localised: Be contained in a particular area of the body
• Regional: Have spread to nearby tissues or lymph nodes
• Metastatic: Have spread throughout the body​

Both grades and stages tell your care team more about your NET cancer and which treatment may be most effective. ​