Prognostic impact of postoperative intra-abdominal infections after elective colorectal cancer resection on survival and local recurrence: a propensity score-matched analysis.

PURPOSE: Several authors have reported an association between anastomotic leak and/or intra-abdominal abscess and oncological survival and recurrence. However, no reports have investigated whether combining anastomotic leak/intra-abdominal abscess and positive drainage culture influences long-term oncological outcomes. Therefore, we defined these complications as postoperative intra-abdominal infections. The present study aimed to evaluate the prognostic impact of postoperative intra-abdominal infections on long-term oncological outcomes after curative stage I-III colorectal cancer surgery. METHODS: We performed a retrospective analysis of 755 consecutive patients with stage I-III colorectal cancer undergoing curative surgery between 2010 and 2015 by performing a propensity score-matched analysis to reduce selection bias. RESULTS: Of the 755 patients, 62 were matched for postoperative intra-abdominal infections analyses. The median follow-up was 48 months. Compared with the non-infections group, the postoperative intra-abdominal infections group had a significantly shorter local recurrence-free survival (P = 0.01 prior to matching, and P = 0.05 after matching). No significant difference was found between the groups in terms of overall, cancer-specific free, recurrence-free, or distant recurrence-free survival. However, multivariate analyses identified postoperative intra-abdominal infections as an independent prognostic factor for local recurrence-free survival (P = 0.04 prior to matching, and P = 0.03 after matching). CONCLUSIONS: In this matched-pair analysis comparing stage I-III colorectal cancer patients with and without postoperative intra-abdominal infections, postoperative intra-abdominal infections were associated with poor local recurrence-free survival, but not overall, cancer-specific free, recurrence-free, or distant recurrence-free survival.