This protocol addresses localised, mismatch repair proficient / microsatellite stable (MMRp/MSS) rectal cancer situated in the lower or middle third of the rectum, where surgical resection is intended and prior neoadjuvant therapy did not achieve the required primary tumour response on MRI restaging.
Localised rectal cancer in the lower or middle third of the rectum, surgery intended, mismatch repair proficient / microsatellite stable. The surgical goal is a microscopically complete (R0) resection with a clear circumferential resection margin (tumour >1 mm from the CRM).
Prior neoadjuvant therapy — SCRT, CRT, or TNT (as appropriate to tumour stage and risk criteria) — was completed. This protocol is entered when MRI restaging after completion of neoadjuvant therapy does not demonstrate the required primary tumour response (downsizing) needed to proceed on the initial surgical plan.
The standard surgical procedure involves total mesorectal excision (TME). Depending on tumour characteristics and the degree of response to prior neoadjuvant treatment, a less extensive surgical alternative may be applicable for selected patients. The complete protocol specifies surgical selection criteria, margin requirements, and regional lymph node management.
DOI: 10.1016/j.annonc.2025.05.528
Management of localised rectal cancer located in the lower or middle third of the rectum when surgery is intended.
The standard surgical approach for locally advanced tumours in the middle or lower third of the rectum remains total proctectomy with TME, which has demonstrated a substantial benefit in decreasing local recurrence rates.
TME is the recommended surgical procedure [III, A].
LE should be considered as an alternative to TME for low-risk tumours (pT1 without unfavourable pathological features) [III, A].
LE is recommended as an alternative to TME after a good response to neoadjuvant CRT or SCRT in baseline cT2 or T3a N0 tumours [I, A].
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