Colorectal cancer staging
This article deals with colorectal cancer staging.
General
TNM staging is very widely used.
TNM staging system
- "Colorectal adenocarcinoma in situ" and "high-grade dysplasia" is used interchangeably by many in the colon and rectum.
- Splitting hairs - adenocarcinoma in situ is invasion into the lamina propria, high-grade dysplasia does not have lamina propria invasion. Ergo, the difference amounts to seeing a desmoplastic stroma (adenocarcinoma) or not seeing one (dysplasia).
Tumour stage
- Tis - in situ (intramucosal).
- T1 - into submucosa (through mucularis mucosae).
- This is different than elsewhere, e.g. in the small bowel tumour cells in the lamina propria is defined as T1. The 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.
- T4 - into something else.
Nodes stage
- N0 - no positive nodes.
- N1 - 1-3 positive nodes.
- N2 - 4+ positive nodes.
- N2a - 4-6 positive nodes.
- N2b - 7+ positive nodes.
Notes:
- Memory device for N2 = 4+ +ve LNs: the number four in chinese sounds like death.[1]
Overall stage
Simple version
Tumour/node grade for stage:[2]
- 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:[3]
- 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
References
- ↑ 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.
- ↑ http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_How_is_colon_and_rectum_cancer_staged.asp