The Impact of Minimally Invasive Gastrectomy on Survival in the USA.

Background: Minimally invasive surgical approaches for gastric adenocarcinoma are increasing in prevalence. Although recent studies suggest such approaches are associated with improvements in short-term outcomes, long-term outcomes have not been well studied. This study aimed to evaluate the impact of minimally invasive gastrectomy on long-term survival.
Methods: The National Cancer Database (NCDB) was used to identify patients who underwent gastrectomy for adenocarcinoma between 2010 and 2015. Patient characteristics were stratified by open and minimally invasive approaches and compared using chi-square and t tests. Unadjusted survival functions were estimated using Kaplan-Meier methodology. Multivariable modeling of risks factors for survival was analyzed with Cox proportional hazard models. Covariate imbalance was controlled using propensity score matching.
Results: The study included 17,449 patients who underwent gastrectomy. Cox proportional hazard modeling demonstrated that minimally invasive surgery improved survival (hazard ratio = 0.86, P < 0.0001). Predictors of worsened survival included community facility type, comorbidities, tumor size, extent of gastrectomy, clinical T and N staging (P < 0.0060 for all). After propensity score matching, minimally invasive surgery had a significantly improved survival at 5 years compared to an open approach, 51.9% versus 47.7% (P < 0.0001). Survival was not significantly different between propensity score-matched patients who received laparoscopic and robotic approaches (P = 0.2611).
Conclusions: Minimally invasive approaches for gastric carcinoma are associated with improved long-term survival. There was no significant difference in survival when comparing laparoscopic to robotic gastrectomy. The mechanisms that drive these improvements deserve further investigation.