Decorative image

Stages

The stage of a large bowel or rectal neuroendocrine tumour (NET) 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 to diagnose a NET. These 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 large bowel and rectal NETs. Doctors usually use the TNM system.

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

Tumour (T)

Tumour describes the size of the cancer. It is divided into 4 main stages.

This is a simplified description of the T stages:

T1 
The tumour is no bigger than 2 cm. It has only grown into the inner lining of the bowel (the mucosa), or into the next layer (the submucosa). 

T2 
The tumour has grown into the muscle layer of the bowel wall. Or the tumour is bigger than 2 cm. 

T3 
The tumour has grown through the muscle layer and into the first part of the outer lining of the bowel wall.

T4 
The tumour has grown through the outer lining of the bowel wall. Or into a nearby organ or structure.

Diagram showing T-stages of bowel neuroendocrine tumours

Node (N)

The N stage describes whether the cancer has spread to the lymph nodes.

N0

N0 means there are no lymph nodes containing NET cells.

N1

N1 means there are NET cells in the nearby lymph nodes. 

Diagram showing N1 stage for NET of the pancreas

Metastasis (M)

The M stage describes whether the tumour has spread to a different part of the body.

M0

M0 means the cancer has not spread to other areas of the body.

M1

M1 means the cancer has spread to other areas of the body, such as the liver.

Diagram showing M1 stage for NET of the pancreas

Treatment

The stage of a NET helps your doctor decide which treatment you need. Treatment also depends on how much the NET cells look like normal bowel cells (grade).

Last reviewed: 
23 Jan 2019
  • Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs)
    J Ramage and others
    Gut, 2012. Vol 61, Pages 6-32

  • AJCC Cancer Staging Manual (8th edition)
    Mahul B. Amin and others
    Springer, 2017

  • ENETS consensus guidelines for the management of patients with digestive neuroendocrine neoplasms: colorectal neuroendocrine neoplasms
    M Caplin and others
    Neuroendocrinology, 2012. Vol. 95, Pages 88-97 

  • Neuroendocrine gastro-entero-pancreatic tumors: ESMO clinical practice guidelines for diagnosis, treatment and follow up
    K Oberg and others
    Annals of Oncology, 2012. Vol 23, Supplement 7, Pages 124-130
     

Information and help