A 65-year-old man with a 4 cm rectal carcinoma 5 cm from the anal verge is staged T3 N1 M0 on MRI. The circumferential resection margin (CRM) on MRI is threatened (tumour within 1 mm of mesorectal fascia). According to current guidelines the optimal initial treatment is:
- A Immediate abdominoperineal resection
- B Short-course preoperative radiotherapy (25 Gy in 5 fractions) followed by immediate surgery
- C Long-course chemoradiotherapy (45–50 Gy with concurrent capecitabine) followed by surgery after 8–12 weeks ✓
- D Total mesorectal excision alone without neoadjuvant therapy
Correct answer: C. Long-course chemoradiotherapy (45–50 Gy with concurrent capecitabine) followed by surgery after 8–12 weeks
Explanation
When the CRM is threatened on MRI (tumour within 1 mm of mesorectal fascia), long-course chemoradiotherapy (LCRT: 45–50 Gy with concurrent fluoropyrimidine) is preferred over short-course RT because it provides tumour downstaging and sterilises the margin, improving R0 resection rates. Surgery is performed 8–12 weeks after completion of LCRT to allow maximum tumour response.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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