A 65-year-old man with rectal adenocarcinoma has MRI showing T3 tumour with clear mesorectal fascia margin (≥2 mm), N1 disease, at the level of 8 cm from the anal verge. Tumour is mobile on digital rectal examination. The MERCURY trial findings most directly support which management strategy?

• A Long-course neoadjuvant chemoradiotherapy followed by TME
• B Short-course preoperative radiotherapy (25 Gy/5 fractions) followed by immediate TME
• C Transanal local excision with adjuvant chemotherapy
• D Upfront total mesorectal excision without neoadjuvant chemoradiotherapy ✓

Explanation

The MERCURY (Magnetic Resonance Imaging and Rectal Cancer European Equivalence) study established that MRI-defined clear circumferential resection margin (CRM ≥1–2 mm) is a reliable predictor of histological CRM clearance. Patients with MRI-predicted clear CRM, mobile tumours, and resectable T3 rectal cancers above 5 cm can proceed to upfront TME without neoadjuvant therapy, reserving neoadjuvant chemoradiotherapy for MRI-predicted threatened/involved CRM. The MERCURY data do not support routine downstaging with radiation when the margin is predicted to be clear.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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