Survival impact of surgical site infection in esophageal cancer surgery: A multicenter retrospective cohort study

Aim: This study was performed to evaluate the oncological impact of surgical site infection (SSI) and pneumonia on long-term outcomes after esophagectomy.Methods:The Japan Society for Surgical Infection conducted a multicenter retrospective cohort study involving 407 patients with curative stage I/II/III esophageal cancer at 11 centers from April 2013 to March 2015. We investigated the association of SSI and postoperative pneumonia with oncological outcomes in terms of relapse-free survival (RFS) and overall survival (OS).Results: Ninety (22.1%), 65 (16.0%), and 22 (5.4%) patients had SSI, pneumonia, and both SSI and pneumonia, respectively. The univariate analysis demonstrated that SSI and pneumonia were associated with worse RFS and OS. In the multivariate analysis, however, only SSI had a significant negative impact on RFS (HR, 1.63; 95% confidence interval, 1.12-2.36; P = 0.010) and OS (HR, 2.06; 95% confidence interval, 1.41-3.01; P < 0.001). The presence of both SSI and pneumonia and the presence of severe SSI had profound negative oncological impacts. Diabetes mellitus and an American Society of Anesthesiologists score of III were independent predictive factors for both SSI and pneumonia. The subgroup analysis showed that three-field lymph node dissection and neoadjuvant therapy canceled out the negative oncological impact of SSI on RFS.Conclusion: Our study demonstrated that SSI, rather than pneumonia, after esophagectomy was associated with impaired oncological outcomes. Further progress in the development of strategies for SSI prevention may improve the quality of care and oncological outcomes in patients undergoing curative esophagectomy.