Colorectal cancer staging
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.
TNM staging system
|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 as per AJCC 7th edition:
|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.
- Tumour deposits are counted separately.
- Tumour deposits are not considered lymph nodes.
Metastasis stage as per AJCC 7th edition:
|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|
Tumour/node grade for stage:
- 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.
Detailed tumour/node grade for stage:
- 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.
- Tumour perforation in colorectal cancer is poor prognosticator; however, it does not affect the (overall) stage. It been suggested that perforated colorectal carcinoma be considered stage IV.
- URL: http://www.cancerresearchuk.org/about-cancer/type/bowel-cancer/treatment/dukes-stages-of-bowel-cancer. Accessed on: 12 January 2016.
- 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.
- URL: http://en.wikipedia.org/wiki/Numbers_in_Chinese_culture#Four. Accessed on: 28 June 2011.
- 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.
- 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.
- 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.