Stage 3 bowel cancer

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 stages

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

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 is the same as one of the following:

  • T4a, N2a, M0

  • T3 - T4a, N2b, M0

  • T4b, N1 - N2, M0

Treatment for stage 3 large bowel (colon) cancer

You have surgery to remove your cancer.

Your surgeon might suggest chemotherapy Open a glossary item before or after surgery.

Chemotherapy before surgery can shrink the cancer to make it easier for to remove. Chemotherapy after surgery can lower the chance of your cancer coming back after surgery.

You might be offered your chemotherapy treatment as part of a clinical trial Open a glossary item.

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

  • a short course of radiotherapy, followed by surgery

  • a course of chemoradiotherapy, followed by surgery

  • a course of chemotherapy, followed by surgery

  • total neoadjuvant therapy (TNT) – this is chemoradiotherapy or radiotherapy and a course of chemotherapy all before surgery

Further treatment

Your doctor might offer you chemotherapy after surgery. This might be if tests on your cancer after surgery show there is a high risk of it coming back. You're more likely to have chemotherapy after surgery if you did not have it before surgery.

Other stages

  • 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

Last reviewed: 
09 Jan 2025
Next review due: 
09 Jan 2028

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