Impact of Postoperative Infectious Complications on Long-Term Survival After Curative Resection for Colorectal Cancer: A Multicenter Study in the Minimally Invasive Era.

Abstract

Aim: Previous studies have reported that postoperative infectious complications (PICs) worsen long-term outcomes after colorectal cancer surgery; however, most were conducted before widespread adoption of minimally invasive surgery. We evaluated the association between PICs and long-term oncological outcomes after curative colorectal cancer resection.

Methods: This multicenter, retrospective cohort study enrolled patients who underwent curative resection for colorectal adenocarcinoma between 2017 and 2021 at 19 hospitals in Japan. PICs were defined as Clavien-Dindo grade≥II infectious complications within 30 days after surgery. Multivariable Cox regression and propensity score matching (1:4) were used to evaluate associations with overall survival (OS) and relapse-free survival (RFS).

Results: Among 5377 patients, 90.6% underwent laparoscopic or robot-assisted surgery, and PICs occurred in 500 (9.3%). In multivariable Cox proportional hazards analysis, PICs were independently associated with worse OS (HR 1.32, 95% CI 1.01-1.72; p = 0.040) and RFS (HR 1.26, 95% CI 1.04-1.54; p = 0.020). After propensity score matching (500 vs. 1931 patients), PICs remained significantly associated with poorer OS and RFS. Patients with PICs had a higher rate of distant recurrence (5-year rate, 19.1% vs. 15.2%; HR 1.33, 95% CI 1.02-1.72; p = 0.03), whereas locoregional recurrence did not differ significantly.

Conclusion: PICs are associated with impaired long-term survival after curative colorectal cancer surgery, even in the modern minimally invasive era. Preventing postoperative infections is important to improve perioperative recovery and long-term oncological outcomes.