Impact of postoperative intra-abdominal infectious complications on survival outcomes in patients with gastric cancer who underwent laparoscopic surgery

Background Postoperative intra-abdominal infection is known to adversely affect survival outcomes in patients with gastric cancer; however, previous reports have investigated this complication only in open surgery. This adverse effect is expected to be weakened by less invasive surgery, such as a laparoscopic approach, by way of maintaining immune function. Methods This study included 1223 patients with gastric cancer who underwent open ( n = 439) or laparoscopic ( n = 784) curative surgery between 2010 and 2015. For each approach, patients were divided into two groups based on presence or absence of postoperative intra-abdominal infection of Clavien–Dindo grade II or higher (C-group and NC-group, respectively). Survival outcomes were compared in propensity-matched cohorts to evaluate the impact of the complication. Results The incidences of Clavien–Dindo ≥ grade II postoperative intra-abdominal infectious complications were 9.7% (43/439) in open surgery and 9.8% (70/714) in laparoscopic surgery. After propensity score matching, 86 patients in open surgery and 138 in laparoscopic surgery were extracted for analysis. The 5-year overall survival rate in the open C-group ( n = 43) was worse than that in the open NC-group ( n = 43) but with no significant difference (70.9% vs. 82.8%, log-rank P = 0.18). The 5-year overall survival rates were equivalent between the laparoscopic C-group ( n = 69) and the laparoscopic NC-group ( n = 69) (90.5% vs. 90.4%, log-rank P = 0.99). Conclusion In general, postoperative intra-abdominal infection adversely affects survival outcomes; however, its impact may be weakened by less invasive surgery. Further evaluation using larger datasets is necessary before reaching definitive conclusions.