A 62-year-old man has a T3N1M0 rectal adenocarcinoma located 7 cm from the anal verge. He receives long-course neoadjuvant chemoradiotherapy and on restaging MRI shows complete clinical response. According to the watch-and-wait approach, which finding mandates surgery rather than surveillance?
- A Regrowth of tumor (re-growth) within the watch-and-wait program ✓
- B Residual mucosal irregularity on rigid sigmoidoscopy
- C Persistent mild mucosal whitening on endoscopy
- D Absence of scar on MRI at 3 months
Correct answer: A. Regrowth of tumor (re-growth) within the watch-and-wait program
Explanation
The watch-and-wait strategy for rectal cancer after complete clinical response is validated by the International Watch and Wait Database (IWWD). The key indication to proceed to surgery is tumor regrowth, which occurs in approximately 25% of cases — typically within the first 2 years. Regrowth is identified by endoscopy or MRI surveillance and surgery at that point can still achieve cure. Residual mucosal irregularity or whitening alone is not sufficient to mandate surgery if there is no biopsy-proven viable tumor.
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.