Postoperative anastomotic leakage after colon cancer surgery may reduce long-term survival

Anastomotic leakage (AL) remains a major cause of postoperative morbidity and mortality after colon cancer surgery and has been discussed potentially impairing long-term survival. However, most available data originate from rectal cancer or mixed cohorts including colon and rectal cancer. Therefore, we investigated the association between AL and overall survival (OS) focusing only on colon cancer.

We identified all patients who underwent surgery for colon cancer at the University Hospital of Wuerzburg between 1 January 2019 and 31 December 2021 via the institutional tumor registry (Onkostar). Rectal cancer patients were not included in the present study. Clinical, surgical, pathologic, and follow-up data (last follow-up June 30, 2025) were extracted and complemented by hospital information systems. OS was defined as time from diagnosis to death or last contact. Multivariable Cox proportional hazards regression-with candidate variables including age, UICC stage, R-status, emergency presentation, diabetes, and immune status-was conducted using stepwise forward selection (entry p < 0.05, exit p > 0.10). Hazard ratios (HRs) with 95% confidence intervals (CIs) were reported and Kaplan-Meier curves plotted to visualize group differences.

The cohort comprised 166 patients; 15 (9%) developed AL. The overall mean survival was 59.6 months (95% CI 55.6-63.7). Baseline tumor localization, UICC stage, and R0 resection rates (98%) were similar between patients with and without AL. Rectal anastomoses exhibited a trend toward higher leak rates than non-rectal ones; other surgical and tumor-related parameters were comparable. In multivariable Cox regression analysis, AL was independently associated with decreased OS (HR 2.97; 95% CI 1.11-7.93; p = 0.030). After adjusting for age, UICC stage, R-status, emergency presentation, diabetes, and immune status, Kaplan-Meier curves confirmed shorter survival in patients experiencing AL.

AL is an independent factor negatively influencing OS of colon cancer. These findings highlight the value of perioperative strategies reducing AL incidence.