A 58-year-old man has a rectal cancer at 7 cm from the anal verge on rigid sigmoidoscopy. MRI pelvis shows T3N1 disease with circumferential resection margin (CRM) predicted to be 1 mm (threatened). According to current UK/NICE and ESMO guidelines, the most appropriate management sequence is:
- A Short-course radiotherapy (25 Gy in 5 fractions) followed by immediate surgery
- B Primary surgery (total mesorectal excision) followed by adjuvant chemotherapy
- C Long-course chemoradiotherapy (45-50 Gy with concurrent fluoropyrimidine) followed by total mesorectal excision at 8-12 weeks ✓
- D FOLFOX chemotherapy followed by reassessment
Correct answer: C. Long-course chemoradiotherapy (45-50 Gy with concurrent fluoropyrimidine) followed by total mesorectal excision at 8-12 weeks
Explanation
A locally advanced rectal cancer with threatened CRM (≤1 mm on MRI) requires downstaging neoadjuvant therapy. Long-course chemoradiotherapy (45-50 Gy over 5 weeks with concurrent capecitabine or 5-FU) is the preferred approach for threatened/involved CRM as it achieves tumour downstaging and CRM clearance. Surgery is delayed to 8-12 weeks post-CRT to allow maximum tumour response. Short-course radiotherapy (SCRT 5×5 Gy) is used for non-threatened CRM T3 tumours where immediate or delayed surgery is planned, but is less effective for downstaging threatened CRM.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.