Grades, types and stages of pancreatic neuroendocrine cancer
Pancreatic neuroendocrine cancers are rare cancers. They start in the 
of the .
Your healthcare team might call them pancreatic neuroendocrine neoplasms, or pancreatic NENs. This means the same thing as pancreatic neuroendocrine cancer. There are 2 key groups of pancreatic neuroendocrine cancer:
- pancreatic
neuroendocrine tumours (NETs ) - pancreatic
neuroendocrine carcinomas (NECs )
A specialist doctor () looks at the cancer cells under a microscope. This tells them:
- whether you have a NET or a NEC
- how fast the cancer cells are growing - this is the grade
The tests and scans you have give information about the of your cancer.
Grading and differentiation
The pathologist looks at a sample of neuroendocrine cancer cells under a microscope.
They look at:
- how abnormal the cancer cells look – doctors call this differentiation
- how quickly or slowly they are dividing and growing – this is grading
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.
Your doctor uses the differentiation to diagnose you with one of the following:
- pancreatic neuroendocrine tumour (pancreatic NET) – these are well differentiated cancers
- pancreatic neuroendocrine carcinoma (pancreatic NEC) – these are poorly differentiated cancers
Grading
Grading refers to cell division and growth rate. To describe this, you might hear the terms mitotic rate or Ki67%. The higher the mitotic rate or Ki67 %, the faster the growth.
The Ki-67 or mitotic index are ways of describing how many cells are dividing. A pathologist counts the number of neuroendocrine 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.
There are 3 grades of pancreatic neuroendocrine tumours (NETs) – grade 1, 2 and 3:
- Grade 1 cancers grow slowly. They are low grade. They have a Ki-67 index of 2% or lower. This means that fewer than 2 in every 100 cells (2%) are dividing.
- Grade 2 cancers grow at a moderate pace (between grade 1 and 3). They are intermediate grade. They have a Ki-67 index between 3% and 20%. This means that between 3 and 20 cells in every 100 cells (3% and 20%) are dividing.
- Grade 3 cancers grow rapidly. They are high grade. They have a Ki-67 index higher than 20% This means that more than 20 in every 100 cells (20%) are dividing.
All pancreatic neuroendocrine carcinomas (NECs) are grade 3.
Types of pancreatic neuroendocrine tumour (NET)
There are 2 groups of pancreatic NETs: Functioning NETs and non functioning NETs.
Non functioning NETs don’t make or release abnormal levels of . So they don't cause hormonal symptoms.
Functioning NETs make and release abnormal levels of hormones. And they cause symptoms. Doctors name each type of functioning NET after the type of hormone that it makes:
- Glucagonomas come from cells that make glucagon.
- Gastrinomas come from cells that make gastrin.
- Insulinomas come from cells that make insulin.
- Somatostatinomas come from cells that make somatostatin.
- VIPomas come from cells that make vasoactive intestinal peptide (VIP).
Types of pancreatic neuroendocrine carcinoma (NEC)
Pancreatic neuroendocrine cancers (NECs) are poorly differentiated cancers. This means the cancer cells look very different to normal neuroendocrine cells. They are fast growing and have often spread to other parts of the body at diagnosis.
They are less common than pancreatic NETs. Around 10 out of 100 (around 10%) neuroendocrine cancers are NECs. There are different types of pancreatic NEC:
- small cell pancreatic NEC
- large cell pancreatic NEC
You can also get neuroendocrine cancer cells mixed in a tumour with a different type of cancer. Doctors call this MiNEN or mixed cell carcinoma.
Unfortunately, pancreatic NECs are harder to treat than NETs. So the outlook () for pancreatic NEC is worse than for pancreatic NETs.
Staging pancreatic neuroendocrine cancer
The stage of a cancer tells you about its size and whether it has spread. Knowing the stage can help your doctor decide which treatment you need.
You have tests and scans which give some information about the stage of the cancer. Sometimes it’s not possible to be certain about the stage until after surgery.
There are different ways to stage pancreatic neuroendocrine cancer. Doctors usually use the TNM system or number system.
TNM stands for tumour, node and metastasis:
- T describes the size of the tumour and how far it has grown through the bowel wall
- N describes whether there are any cancer cells in the lymph nodes
- M describes whether the tumour has spread to a different part of the body
Or your doctor might tell you the number stage of your neuroendocrine cancer. Number staging systems use the TNM system to divide cancers into stages. Most types of cancer have 4 stages, numbered from 1 to 4.
Below we have a simplified description of TNM and number staging for pancreatic neuroendocrine cancers. The information on this page is about staging pancreatic NETs. For pancreatic neuroendocrine carcinoma (NEC), doctors use a different staging system. They use the same staging system as for the more common type of pancreatic cancer.
T describes the size of the tumour (area of the cancer). There are 4 stages:
T1 stage
T1 means the tumour is less than 2 cm and contained within the pancreas.
T2 stage
T2 means the tumour is between 2 cm and 4 cm and contained within the pancreas.
T3 stage
T3 means the tumour is more than 4 cm and it is contained within the pancreas. Or it has grown into the small bowel (duodenum) or the bile duct.
T4 stage
T4 means the NET has grown outside the pancreas into nearby tissues, organs or structures such as:
-
one of the blood vessels
-
stomach
-
spleen
-
bowel
-
adrenal gland
The N stage describes whether the cancer has spread to the lymph nodes. There are 2 stages:
N0 stage
N0 means there are no lymph nodes containing NET cells.
N1 stage
N1 means there are NET cells in the nearby lymph nodes.
The M stage describes whether the cancer has spread to a different part of the body. There are 2 stages:
M0 stage
M0 means the cancer has not spread to other areas of the body.
M1 stage
M1 means the cancer has spread to other areas of the body, such as the liver.
Your doctor might tell you the number stage of your pancreatic NET. This system divides pancreatic NETs into 4 main groups, depending on the size of the tumour and whether it has spread. Below is a simplified version.
Stage 1 is the earliest stage. It means the NET is no bigger than 2 cm and contained within the pancreas. In the TNM staging, this is the same as T1, N0, M0.
Stage 2 means one of the following. The NET:
- is contained within the pancreas and is between 2 cm and 4 cm.
- is bigger than 4 cm
- has grown into the small bowel (duodenum) or bile duct
In the TNM staging, this is the same as T2 or T3, N0, M0.
Stage 3 means one of the following. The NET has grown outside the pancreas into:
- nearby organs or blood vessels
- nearby lymph nodes
In the TNM staging, this is the same as T4, N0, M0 or any T, N1 M0
Stage 4 means the cancer has spread to other parts of the body such as the liver. In the TNM staging, this is the same as any T, any N, M1. Doctors might call this advanced or metastatic cancer.
Treatment for pancreatic neuroendocrine cancer
The stage of the cancer helps your doctor decide which treatment you need. Treatment also depends on:
-
the type of pancreatic neuroendocrine cancer you have
-
where the cancer is
-
your general health and fitness
