Stages of pancreatic NETs

The stage of a pancreatic neuroendocrine tumour (NET) tells you its size and whether it has spread. Doctors use the same staging systems for all types of pancreatic NETs.

The tests and scans you have when diagnosing a NET give information about the stage.

There are different ways to stage pancreatic NETs. Doctors can use the TNM system or a number system. This helps your doctor decide which treatment you need.

TNM stage

In the UK, doctors usually use a staging system called TNM. TNM stands for tumour, node and metastasis:

T describes the size of the tumour
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

The TNM staging described here was created by the European Neuroendocrine Tumor Society (ENETS).

Tumour (T)

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.

Diagram showing a T1 NET of the pancreas

T2 stage

T2 means the tumour is between 2 cm and 4 cm and contained within the pancreas.

Diagram showing a T2 NET of the pancreas

T3 stage

T3 means the tumour is more than 4 cm. It is contained within the pancreas or has grown into the small bowel (duodenum) or the bile duct.

Diagram showing a T3 NET of the pancreas

T4 stage

T4 means the tumour has grown outside the pancreas into:

one of the blood vessels
stomach
spleen
bowel
adrenal gland

Diagram showing a T4 NET of the pancreas

Node (N)

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.

Metastasis (M)

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.

Number stage

Your doctor might tell you the number stage of the NET. This system divides pancreatic NETs into 4 main groups, depending on the size of the cancer and whether it has spread.

Stage 1

This is the earliest stage. It means the tumour is less than 2 cm and contained within the pancreas. In the TNM staging, this is the same as T1, N0, M0.

Stage 2

Stage 2 is divided into 2A and 2B.

Stage 2A means the tumour is contained within the pancreas and is between 2 cm and 4 cm. In the TNM staging, this is the same as T2, N0, M0.

Stage 2B means the tumour is bigger than 4 cm. It is contained within the pancreas or has grown into the small bowel (duodenum) or bile duct. In the TNM staging, this is the same as T3, N0, M0.

Stage 3

Stage 3 is divided into 3A and 3B.

Stage 3A means the tumour has grown outside the pancreas into the blood vessels, stomach or bowel. But it hasn’t grown into the lymph nodes. In the TNM staging, this is the same as T4, N0, M0.

Stage 3B means the tumour has grown outside the pancreas and into the lymph nodes. It hasn’t spread to other areas of the body. In the TNM staging, this is the same as Any T, N1, M0.

Stage 4

Stage 4 means the tumour 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.

Treatment

The stage of the NET helps your doctor decide which treatment you need. Treatment also depends on:

the type of pancreatic NET you have
where the cancer is
other health conditions you may have