Near-complete clinical response after neoadjuvant therapy in rectal cancer: Decision-making between organ preservation and surgery

Table 1 Key findings suggestive of favorable or unfavorable near-complete clinical response and their management implications

Finding	Interpretation (risk of residual tumor)	Suggested clinical implication
Endoscopic nCR1
Small nodularity	Variable risk; may still evolve to cCR (favorable nCR pattern)	Supports repeat reassessment at 6-12-week intervals, with close surveillance limited to the first 6 months
Irregular mucosa	Intermediate risk; may represent either ongoing tumor regression or residual disease (unfavorable nCR pattern)	Consider early surgical intervention or intensified evaluation
Superficial ulceration	Increased likelihood of residual tumor (unfavorable nCR pattern)	Consider early surgical intervention or intensified evaluation
MRI nCR2
Absence of EMVI	Favorable biologic response pattern (favorable nCR pattern)	Supports repeat reassessment at 6-12-week intervals, with close surveillance limited to the first 6 months
Low rectal tumor location	Associated with an increased probability of complete response (favorable nCR pattern)	Supports repeat reassessment at 6-12-week intervals, with close surveillance limited to the first 6 months

¹Endoscopic features associated with favorable or unfavorable near-complete clinical response, adapted from Williams et al[18].

²Magnetic resonance imaging-based predictors of complete response, including tumor location and extramural vascular invasion status, adapted from Yilmaz et al[22].

nCR: Near-complete clinical response; cCR: Clinical complete response; MRI: Magnetic resonance imaging; EMVI: Extramural venous invasion.