Relationship between Clavien-Dindo classification and long-term survival outcomes after curative resection for gastric cancer: A propensity score-matched analysis

Background: The impact of postoperative complications (POCs) on the long-term survival outcomes after curative resection for gastric cancer has seldom been reported. The purpose of this study was to evaluate the relationship between the severity of POCs and long-term survival outcomes after curative resection for gastric cancer. Methods: The study analyzed 3091 patients who underwent curative resection for gastric cancer in a single center between June 2009 and June 2015. Patients were divided into two groups based on the occurrence or absence of postoperative complications which were recorded using the Clavien-Dindo classification. Long-term survival outcomes were compared between groups after propensity score matching (PSM). Results: A total of 3091 patients were included in the entire cohort. After PSM, no significant difference in baseline data was observed between the complications (C) group (n = 375) and no complications (NC) group (n = 375). With a median follow-up of 51 months, POCs were associated with decreased 5-year overall survival (OS) (51.7% vs. 67.5%, P < 0.001), disease-free survival (DFS) (49.9% vs. 65.6%, P < 0.001), and disease-specific survival (DSS) (53.9% vs. 68.8%, P < 0.001). Increasing Clavien-Dindo grades from II to IV was significantly associated with a corresponding decrease in OS (60, 48.3, 34%, P = 0.010), DFS (58.3, 46.3, 32.1%, P < 0.001) and DSS (62.9, 50.3, 34%, P < 0.001). Multivariate analysis confirmed POCs was an independent prognostic factor for decreased OS, DFS, and DSS (all P < 0.05). Conclusions: POCs had a negative impact on long-term survival outcomes after curative resection for gastric cancer. The negative effects were also increased with higher Clavien-Din do grades.