Delaying surgery after neoadjuvant chemoradiotherapy for rectal cancer may reduce postoperative morbidity without compromising prognosis

Background: This retrospective study investigated whether the interval between neoadjuvant chemoradiotherapy and surgery for rectal cancer influences postoperative morbidity or prognosis. Methods: Data from 189 patients receiving neoadjuvant 5-fluorouracil-based chemoradiotherapy were examined. Associations between interval length and clinicopathological characteristics were analysed. Results: The median interval was 73 (range 6-215) days. Operations performed were abdominoperineal resection (60.3 per cent), anterior resection (37.6 per cent) and Hartmann's procedure (2.1 per cent). Forty-six patients (24.3 per cent) received postoperative chemotherapy. Interval was not significantly associated with pathological tumour (P = 0.648) or node (P = 0.964) category after chemoradiotherapy, or pathological complete response (P = 0.499). Logistic regression showed that shorter intervals (by I week) independently predicted anastomotic leakage (odds ratio (OR) 0.97 (95 per cent confidence interval (c.i.) 0.94 to 1.00)) and perineal wound complications (OR 0.97 (0.95 to 0.99)). Interval was not related to local recurrence (hazard ratio (HR) 1.01 (95 per cent c.i. 1.00 to 1.02)), metastasis (HR 1.00 (0.99 to 1.01)) or death (HR 1.00 (0.99 to 1.01)). Only circumferential resection margin and nodal involvement were independent predictors of survival. Conclusion: Delaying surgery beyond 8 weeks after neoadjuvant chemoradiotherapy may reduce postoperative morbidity, without compromising prognosis.