Stage 3

Stage 3 bowel (colon and rectal) cancer has spread to nearby lymph nodes, but hasn't spread to distant body parts. It's divided into 3 groups - 3A, 3B and 3C.

Stage 3A

Stage 3A means one of the following:

  • the cancer is still in the inner or muscle layer of the bowel wall, and it has spread to between 1 to 3 nearby lymph nodes or to areas of tissue close to the lymph nodes
Diagram showing Stage 3A1 bowel cancer
  • the cancer is in the inner layer of the bowel wall and has spread to between 4 and 6 nearby lymph nodes
Diagram showing Stage 3A2 bowel cancer

Stage 3B

Stage 3B means one of the following:

  • the cancer has grown into the outer lining of the bowel wall or into the tissue layer covering the organs in the tummy (abdomen) and it has spread to between 1 and 3 nearby lymph nodes or to areas of fat close to the lymph nodes
Diagram showing Stage 3B1 bowel cancer
  • the cancer has grown into the muscle or outer lining of the bowel wall and between 4 to 6 nearby lymph nodes contain cancer
Diagram showing Stage 3B2 bowel cancer
  • the cancer is still in the inner or muscle layer of the bowel wall and it has spread to 7 or more nearby lymph nodes
Diagram showing Stage 3B3 bowel cancer

Stage 3C

Stage 3C means one of the following;

  • the cancer has grown through the outer lining of the bowel wall into the tissue layer covering the organs in the tummy (abdomen) and between 4 to 6 nearby lymph nodes contain cancer
Diagram showing Stage 3C1 bowel cancer
  • the cancer has grown into the outer lining of the bowel wall or into the tissue layer covering the organs in the abdomen and it has spread to 7 or more nearby lymph nodes
Diagram showing Stage 3C2 bowel cancer
  • the cancer has grown through the bowel wall into other nearby organs and it has spread to at least one nearby lymph node or to areas of fat close to the lymph nodes
Diagram showing Stage 3C3 bowel cancer

TNM staging

The TNM staging system stands for Tumour, Node, Metastasis.

  • T describes the size of the tumour
  • N describes whether there are any cancer cells in the lymph nodes
  • M describes whether the cancer has spread to a different part of the body

In TNM staging stage 3A is one of the following:

  • T1 – T2, N1- N1c, M0
  • T1, N2a, M0

In TNM staging, stage 3B is one of the following:

  • T3 – T4a, N1-N1c, M0
  • T2-T3, N2a, M0
  • T1-T2, N2b, M0

In the TNM staging, stage 3C  the same as one of the following;

  • T4a, N2a, M0
  • T 3- T4a, N2b, M0
  • T4b, N1-N2, M0

Treatment for stage 3 large bowel (colon) cancer

You have surgery to remove your cancer. Most people have chemotherapy after surgery. You might take chemotherapy as a tablet, or have it into your vein (intravenous).  

This might be as part of a clinical trial.

Treatment for stage 3 cancer of the back passage (rectal cancer)

The main treatments are:

  • surgery
  • radiotherapy
  • chemotherapy
  • chemotherapy combined with radiotherapy (chemoradiotherapy)

You might have:

  • surgery as your only treatment, or followed by chemoradiotherapy if the risk of your cancer coming back is higher than the surgeon previously thought
  • a short course of radiotherapy, followed by surgery
  • a course of chemoradiotherapy, followed by surgery

Further treatment

Your doctor might offer you chemotherapy after surgery if you have a high risk of your cancer coming back.

Other stages

Last reviewed: 
21 Jan 2022
Next review due: 
21 Jan 2025
  • Colorectal cancer
    The National Institute for Health and Care Excellence (NICE), 2020. Updated December 2021

  • Localised colon cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.
    G Argilés and others
    Annals of Oncology, 2020. Volume 31, Issue 10 Pages 1291-1305

  • Rectal cancer: ESMO clinical practical guidelines for diagnosis, treatment and follow up
    R Glynne-Jones and others
    Annals of Oncology, 2017. Volume 28, Pages 422-440

  • AJCC Cancer Staging Manual (8th Edition)
    American Joint Committee on Cancer, 2017

  • Association of Coloproctology of Great Britain & Ireland (ACPGBI): Guidelines for the Management of Cancer of the Colon, Rectum and Anus (2017). 
    Colorectal disease Volume 19, issue S1,  Pages 1-97

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