When the consultant identifies a bowel cancer they will give a formal diagnosis. The key part of this is the staging. This describes the extent to which the cancer has developed.
The staging appears as a series of letters and numbers, eg pT3 N1a M0 V1 R0
It is important to understand your diagnosis. The links listed below will help you. No one site gives you all of the information, but between them you can learn about the TNM staging system and its nuances. The Radiopaedia pages are especially useful for understanding the prefixes and suffixes.
Note: The diagnosis will often contain additional information from histology or pathology describing the genetic aspects of a tumour and your genome. Please go to our Biomarkers page for more information about these.
- Anal Cancer Staging – Bowel Cancer UK
- Biomarkers – What they mean – BCSGUK
- Bowel Cancer Staging – Bowel Cancer UK
- Bowel Cancer Staging – Cancer Research UK
- Colorectal Cancer Staging – American Cancer Society – detailed staging descriptions
- Colorectal Cancer Staging and Treatment – US Government. Excellent graphics showing what the staging means.
- Colon Cancer staging – Radiopaedia. Detailed TNM descriptions
- Rectal Cancer staging – Radiopaedia. – Details TNM descriptions
- TNM Staging – Radiopaedia. Details of the small letter prefixes and suffixes
- Understanding a Colorectal Diagnosis by Stage – Colorectal Cancer Alliance – USA
- R = Residual Tumour Classification – see below
- Detailed Explanation of Cancer Staging – Download PDF
Residual Tumour Classification
| R0 > 1 mm | No residual tumor, minimal distance between tumor and resection margin; margin ≥1 mm† |
| R1 ≤ 1 mm | No residual tumor, minimal distance between tumor and resection margin; margin ≤1 mm† |
| R1-dir | Microscopic residual tumor, tumor directly at the resection margin (tumor transected)† |
| R2a | Local macroscopic residual tumor† |
| R2b | Distant macroscopic residual tumor† |
| R2c | Macroscopic residual tumor in both sites† |
A uniform residual tumor (R) classification – Scientific Paper