A 55-year-old woman with locally advanced rectal cancer (T3N1M0) undergoes neoadjuvant long-course chemoradiotherapy. Restaging MRI at 8 weeks shows near-complete response with only a small residual mucosal irregularity (ymrTRG 2). The multidisciplinary team considers a watch-and-wait approach. What is the key surveillance component to detect early local regrowth?
- A Rigid proctoscopy and pelvic MRI every 3 to 6 months for the first 2 years ✓
- B Serial CEA measurements every 3 months
- C PET-CT every 6 months
- D Flexible sigmoidoscopy annually
Correct answer: A. Rigid proctoscopy and pelvic MRI every 3 to 6 months for the first 2 years
Explanation
In the watch-and-wait strategy after clinical complete response, local regrowth occurs in approximately 25 to 30 percent of cases, predominantly within the first 2 years. Surveillance requires rigid proctoscopy (or high-definition flexible endoscopy) combined with pelvic MRI every 3 to 6 months to detect early regrowth amenable to salvage surgery. CEA alone lacks sensitivity for local recurrence. PET-CT is not routine surveillance. Annual endoscopy is insufficient to catch early regrowth.
Reference: Diseases of the Colon and Rectum, 2020 (Habr-Gama criteria) ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.