Grades and stages of neuroendocrine cancer
The tests and scans you have give information about the stage and grade of your cancer.
A specialist doctor (
) looks at the cancer cells under a microscope. This tells them how quickly or slowly the cancer cells are growing. This is the grade. The stage of a neuroendocrine cancer tells you about its size and whether it has spread.
Neuroendocrine cancers are a group of cancers that develop in cells of the . You might also hear the term neuroendocrine neoplasm (NEN). This means the same as neuroendocrine cancer.
There are 2 key groups of neuroendocrine cancer:
neuroendocrine tumours (NETs ) neuroendocrine carcinomas (NECs )
NETs and NECs are very different. So it is important to know which one you have. Talk to your doctor or specialist nurse if you are not sure.
Grading and differentiation
Differentiation
This refers to how different the neuroendocrine cancer cells look. This is in comparison to healthy neuroendocrine cells:
- Well differentiated cancers look abnormal. But they still have some similarities to normal neuroendocrine cells.
- Poorly differentiated cancers look very abnormal. They are not like normal neuroendocrine cells at all.
Neuroendocrine tumours (NETs) are well differentiated (WD) cancers.
Neuroendocrine carcinoma (NECs) are poorly differentiated (PD) cancers.
Grading
This is about cell division and growth rate. To describe this, you might hear the terms mitotic rate or Ki67 score or percentage (%). The higher the mitotic rate or Ki67%, the faster the growth.
There are 3 grades of neuroendocrine tumours (NETs) – grade 1, 2 and 3a:
- Grade 1 cancers grow slowly. They are low grade.
- Grade 2 grow at a moderate pace (between 1 and 3). They are intermediate grade.
- Grade 3a grow rapidly. They are high grade.
All neuroendocrine carcinomas (NECs) are grade 3b.
Ki–67 index test
The Ki-67 or mitotic index are ways of describing how many cells are dividing. A specialist doctor (pathologist) counts the number of cancer cells that have started to divide into 2 new cells (mitoses) under a microscope. And a special stain measures the Ki-67 value.
Your doctor might tell you the number of cells that are dividing (number of mitoses), or you may see this on your pathology report. This helps your doctor decide which treatment you need.
Ki-67 index of