staging of colorectal cancer using TNM classification
Last reviewed 01/2018
staging of colorectal cancer
Staging of newly diagnosed colorectal cancer includes the assessment of local spread and detection of the presence or absence of distant metastases (1). Offer
- contrast-enhanced CT of the chest, abdomen and pelvis; should be offered to all patients who are diagnosed with colorectal cancer to estimate the stage of the disease
- MRI to assess the risk of local recurrence to all patients with rectal cancer unless it is contraindicated
- endorectal ultrasound to patients with rectal cancer if MRI shows disease amenable to local excision or if MRI is contraindicated
Several staging systems for colorectal cancer have been described.
- TNM Staging System developed by the American Joint Commission on Cancer (AJCC) is the most widely used method (2):
- T - primary tumour.
- T0: no evidence of primary tumour
- Tis carcinoma in situ: intraepithelial or invasion of the lamina propria
- T1 the tumour is confined to the submucosa
- T2 the tumour has grown into (but not through) the muscularis propria
- T3 the tumour has grown into (but not through) the serosa
- T4 the tumour directly invades other organs or structures, and/or perforates
visceral peritoneum
- N - regional lymph nodes
- N0: no regional nodes involved.
- N1: 1-3 regional nodes involved.
- N2: 4 or more regional nodes involved
- M - distant Metastasis
- M0: no distant metastasis.
- M1: distant metastasis present (may be transcoelomic spread)
- stage grouping
- stage 0 - Tis N0 M0 (carcinoma in situ)
- stage 1 - T1 N0 M0, T2 N0 M0
- stage 2 - T3 T4 N0 M0
- stage 3 - Any T1-2, N1, M0, any T3-4, N1 M0, any T N2 M0
- stage 4 - any T, any N, M1
- Dukes’ staging equivalence to TNM classification-
- Dukes’ stage A = T1N0M0 or T2N0M0
- Dukes’ stage B = T3N0M0 or T4N0M0
- Dukes’ stage C = any T, N1, M0 or any T, N2, M0
- Dukes’ stage D = any T, any N, M1
Note:
- findings of digital rectal examinations should not be used as part of the staging assessment
Reference: