Abstract / Summary
Abstract Background To compare postoperative survival after preoperative chemoradiotherapy versus upfront surgery in patients with early-onset clinical stage II–III rectal cancer who underwent surgical resection in East and Southeast Asia. Methods This retrospective study included patients aged 18–49 years diagnosed during 2013–2023 who underwent resection at 11 East and Southeast Asian institutions. Propensity-score weighting targeted patients receiving preoperative chemoradiotherapy. Disease-free and overall survival from surgery were evaluated using weighted Kaplan–Meier estimates and facility-stratified Cox models with robust variance estimation. Results The cohort comprised 415 patients: 270 underwent upfront surgery and 145 received preoperative chemoradiotherapy. Median follow-up was 4.17 years. Disease-free survival was analyzed in 410 patients with 125 events, and overall survival in 411 patients with 37 deaths. Preoperative chemoradiotherapy was not significantly associated with disease-free survival (hazard ratio 1.55, 95% confidence interval 0.95–2.52; P = 0.081) or overall survival (hazard ratio 1.36, 95% confidence interval 0.61–3.01; P = 0.454). Weighted 5-year disease-free survival was 66.4% after upfront surgery and 58.6% after preoperative chemoradiotherapy; corresponding overall survival was 89.8% and 84.9%. Locoregional recurrence was recorded in nine and eight patients, respectively. Conclusion Preoperative chemoradiotherapy was not significantly associated with improved postoperative survival among these resected patients; the findings do not establish equivalence. Treatment selection should incorporate pretreatment local tumor risk, and future studies should evaluate treatment completion and functional outcomes.