A 45-year-old man presents with rectal bleeding and a mass at the anal margin. Biopsy shows squamous cell carcinoma. What is the standard first-line treatment for squamous cell carcinoma of the anal canal?

• A Abdominoperineal resection (APR) with end colostomy
• B Wide local excision with 1 cm margins
• C Cisplatin-based chemotherapy alone
• D Nigro protocol: concurrent chemoradiotherapy with 5-FU and mitomycin C ✓

Explanation

Squamous cell carcinoma of the anal canal is treated with the Nigro protocol (definitive chemoradiotherapy): radiotherapy 45-54 Gy combined with concurrent 5-fluorouracil and mitomycin C (or cisplatin). This organ-preserving regimen achieves complete response in over 80% of cases, avoiding permanent colostomy. APR is reserved for persistent or recurrent disease after chemoradiotherapy. Wide local excision is acceptable only for T1 perianal margin tumours not involving the sphincter complex.

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.