Outcomes of Response-Based Watch-and-Wait and Surgical Management After Total Neoadjuvant Therapy for Rectal Cancer: A Systematic Review and Meta-analysis.

BackgroundTotal neoadjuvant therapy (TNT) increases clinical complete response rates in locally advanced rectal cancer (RC), allowing response-based management strategies such as watch-and-wait (WW) as an alternative to total mesorectal excision (TME). Outcomes associated with WW after TNT remain incompletely defined. This study aimed to compare oncologic and organ-preservation outcomes between WW and surgical management following TNT.MethodsA systematic search was conducted in PubMed, Scopus, and Cochrane Central up to April 2025. Observational studies comparing WW and TME following TNT were included. Pooled odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed with I2 statistics. Secondary outcomes included tumor regrowth, salvage surgery, and permanent stoma. Risk of bias was evaluated using ROBINS-I.ResultsSix studies comprising 793 patients were analyzed. WW showed no significant difference compared with TME regarding local recurrence (OR 1.36, 95% CI 0.07-26.17; I2 = 80%), distant metastases (OR 0.62, 95% CI 0.29-1.33; I2 = 49%), 5-year disease-free survival (HR 0.97, 95% CI 0.71-1.31; I2 = 51.7%), or overall survival (HR 1.03, 95% CI 0.81-1.30; I2 = 27.9%). Permanent stoma rates were lower with WW (OR 0.12, 95% CI 0.01-1.23; I2 = 71%), becoming significant after sensitivity analysis (OR 0.04, 95% CI 0.01-0.19).ConclusionWW after TNT offers oncologic outcomes comparable to TME, with high organ preservation and reduced surgical morbidity in highly selected patients.