Colorectal cancer (staging)

Last revised by Yuranga Weerakkody on 09 Jan 2023

Colorectal carcinoma staging can be performed using two systems. The traditional Dukes staging system has largely been replaced by the TNM system but is nonetheless often used clinically.


Dukes (Astler-Coller modification)
  • stage A: confined to mucosa

  • stage B: through muscularis propria

  • stage C: local lymph node involvement

  • stage D: distant metastases

TNM staging (8th edition)
Primary tumour staging (T)
  • Tx: primary tumour cannot be assessed

  • T0: no evidence of primary tumour

  • Tis: carcinoma in situ

  • T1: into (but not through) submucosa

  • T2: into (but not through) muscularis propria

  • T3

    • through muscularis propria into subserosa, or

    • into non-peritonealised pericolic/perirectal tissues

  • T4a: penetration of the visceral peritoneal layer

  • T4b: penetration or adhesion to adjacent organs

Nodal status (N)
  • Nx: nodes cannot be assessed

  • N0: no evidence of nodal involvement

  • N1a: involvement of one regional node

  • N1b: involvement of 2-3 regional nodes

  • N1c: deposits involving serosa or non-peritonealised pericolic/perirectal tissues without regional nodal metastasis

  • N2a: involvement of 4-6 nodes

  • N2b: involvement of ≥7 nodes

Metastases (M)
  • Mx: presence of metastases cannot be assessed

  • M0: no evidence of metastases

  • M1a: distant metastases confined to one organ (e.g. liver, lung, ovary, non-regional node), without peritoneal metastases

  • M1b: distant metastases to more than one organ, but without peritoneal metastases

  • M1c: metastases to the peritoneum, with or without metastases in other organs

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Cases and figures

  • Case 1: T3N2M1
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  • Case 2: T4aN1bMX
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  • Case 3: T4N2M1
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  • Case 4: T2N1 rectal cancer
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  • Case 5: T4 with rectovesical fistula
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