Colorectal cancer staging

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This article deals with colorectal cancer staging.


TNM staging is very widely used. There is also the Dukes' system, which in many respects is quite similar.[1]

TNM staging system

Tumour stage

Stage Criteria Notes
Tis in situ (intramucosal) ‡ high-grade dysplasia, "intramucosal colorectal carcinoma", and "colorectal adenocarcinoma in situ" are used interchangeably by many in the colon and rectum; high-grade dysplasia is the preferred term - see "intramucosal colorectal carcinoma"
T1 into submucosa (through mucularis mucosae), not into muscularis propria different than elsewhere in GI tract; in the small bowel tumour cells in the lamina propria is defined as T1; rationale for the T1 definition in CRC is that no lymphatics are present in the mucosa, ergo no risk of distant spread
T2 into muscularis propria
T3 into fat beyond musclaris propria
T4a invasion of the visceral peritoneum tumour within 1 mm is not T4a; however, it should prompt cutting deepers and taking more sections
T4b grows into something else

Nodal stage

Nodal stage as per AJCC 7th edition:[2]

Stage Criteria Notes
N0 no positive nodes
N1a 1 positive node
N1b 2-3 positive nodes
N1c tumour deposit(s) present with all lymph nodes negative lesion must be in the drainage bed of the tumour; lesions not in the drainage bed are M1b
N2a 4-6 positive nodes
N2b 7+ positive nodes


  • Memory device for N2 = 4+ positive LNs: the number four in chinese sounds like death.[3]
  • Tumour deposits are counted separately.
    • Tumour deposits are not considered lymph nodes.

Metastasis stage

Metastasis stage as per AJCC 7th edition:[2]

Stage Criteria Notes
M1a one organ only lung, liver, ovary or nonregional lymph node
M1b more than one organ or peritoneal involvement tumour deposits are in the drainage bed of the tumour - they are not classified as metastases

Overall stage

Simple version

Tumour/node grade for stage:[4]

  • Stage I - T1 or T2 N0 M0.
  • Stage II - T3 or T4 N0 M0.
  • Stage III - Tx N1 or N2 M0.
  • Stage IV - Tx Nx M1.

Complex version

Detailed tumour/node grade for stage:[5]

  • Stage I - T1 or T2.
  • Stage IIA - T3.
  • Stage IIB - T4.
  • Stage IIIA - T1 N1 or T2 N1.
  • Stage IIIB - T3 N1 or T4 N1.
  • Stage IIIC - Tx N2.
  • Stage IV - Tx Nx M1.


See also


  1. URL: Accessed on: 12 January 2016.
  2. 2.0 2.1 American Joint Committee on Cancer (2010). AJCC Cancer Staging Handbook: From the AJCC Cancer Staging Manual (7th ed.). New York: Springer. pp. 198. ISBN 978-0387884424.
  3. URL: Accessed on: 28 June 2011.
  4. Shiau, Carolyn; Toren, Andrew (2006). Toronto Notes 2006: Comprehensive Medical Reference (Review for MCCQE 1 and USMLE Step 2) (22nd edition (2006) ed.). Toronto Notes for Medical Students, Inc.. pp. GS27. ISBN 978-0968592861.
  6. Anwar, MA.; D'Souza, F.; Coulter, R.; Memon, B.; Khan, IM.; Memon, MA. (Aug 2006). "Outcome of acutely perforated colorectal cancers: experience of a single district general hospital.". Surg Oncol 15 (2): 91-6. doi:10.1016/j.suronc.2006.09.001. PMID 17049848.
  7. Ogawa, M.; Watanabe, M.; Eto, K.; Omachi, T.; Kosuge, M.; Hanyu, K.; Noaki, L.; Fujita, T. et al. (May 2009). "Clinicopathological features of perforated colorectal cancer.". Anticancer Res 29 (5): 1681-4. PMID 19443386.