The Association Between Anastomotic Leak and 5-Year Oncologic Outcomes in Patients Undergoing Colorectal Cancer Resection: A Retrospective Cohort Study

Background: Anastomotic leak (AL) is a serious complication following colorectal cancer (CRC) resection. Its influence on long-term oncologic outcomes, including recurrence and survival, remains controversial. Methods: This retrospective cohort study aimed to evaluate the prevalence of AL following CRC resection with anastomosis for stage 1–3 CRC. Clinical, operative, oncologic, and follow-up data were collected. AL was diagnosed within 30 days postoperatively. Primary outcomes included recurrence and mortality. Results: A total of 204 patients were included, of whom 25 (12.3%) developed AL. CRC recurrence occurred in 28.0% of patients with AL compared with 24.6% without AL (p = 0.712). Median time to recurrence was shorter in patients with AL (7 vs. 15 months, p = 0.064). One-year mortality was higher in patients with AL (20.0% vs. 3.9%, p = 0.008), and time to mortality was shorter (7 vs. 35 months, p = 0.048). However, AL was not independently associated with mortality or poor outcome on multivariable analysis. Conclusions: AL following CRC resection was associated with earlier mortality and a trend toward earlier recurrence, although no independent association with long-term oncologic outcomes was demonstrated. A larger prospective study with standardized leak definitions would better clarify the relationships between AL and CRC outcomes.