Impact of treatment guidelines and pivotal clinical trial results on a surgeon's decision regarding treatment for gastric cancer: a retrospective cohort study using the National Clinical Database

PurposesThe present study evaluated the impact of clinical guidelines for gastric cancer surgery on surgeons' choice of procedure in real-world practice. We focused on the 2014 guideline revision recommending laparoscopic surgery and the evidence concerning splenectomy for prophylactic lymphadenectomy reported in 2015 using the National Clinical Database, which is the most comprehensive database in Japan.MethodsWe investigated the monthly percentages of laparoscopic distal gastrectomies performed for stage I gastric cancer (LDG%) and splenectomies performed during total gastrectomy for advanced cancer (TGS%) between 2014 and 2017. We evaluated the descriptive statistics of the time-series changes in the LDG%, TGS%, and annual trends of outcomes.ResultsIn total, 124,787 patients were enrolled. The mean LDG% and TGS% were 69.8% and 9.2%, respectively. The LDG% and TGS% were 66.4% and 16.7%, respectively, in January 2014 and 73.1% and 5.9%, respectively, in December 2017. LDG% consistently increased, and TGS% showed a consistent downward trend throughout the observation period. There was no significant change in this trend after the publication of the guideline recommendations or clinical trial results.ConclusionNo significant changes in surgical procedures were observed after publication of the guidelines or results of clinical trials.