Prognostic factors of minimally invasive surgery for gastric cancer: Does robotic gastrectomy bring oncological benefit?

BACKGROUND: Gastric cancer is the third leading cause of cancer-related death worldwide and surgical resection remains the sole curative treatment for gastric cancer. Minimally invasive gastrectomy including laparoscopic and robotic approaches has been increasingly used in a few decades. Thus far, only a few reports have investigated the oncological outcomes following minimally invasive gastrectomy. AIM: To determine the 5-year survival following minimally invasive gastrectomy for gastric cancer and identify prognostic predictors. METHODS: This retrospective cohort study identified 939 patients who underwent gastrectomy for gastric cancer during the study period. After excluding 125 patients with non-curative surgery (n = 77), other synchronous cancer (n = 2), remnant gastric cancer (n = 25), insufficient physical function (n = 13), and open gastrectomy (n = 8), a total of 814 consecutive patients with primary gastric cancer who underwent minimally invasive R0 gastrectomy at our institution between 2009 and 2014 were retrospectively examined. Accordingly, 5-year overall and recurrence-free survival were analyzed using the Kaplan–Meier method with the log-rank test and Cox regression analyses, while factors associated with survival were determined using multivariate analysis. RESULTS: Our analysis showed that age > 65 years, American Society of Anesthesiologists (ASA) physical status 3, total or proximal gastrectomy, and pathological T4 and N positive status were independent predictors of both 5-year overall and recurrence-free survival. Accordingly, the included patients had a 5-year overall and recurrence-free survival of 80.3% and 78.2%, respectively. Among the 814 patients, 157 (19.3%) underwent robotic gastrectomy, while 308 (37.2%) were diagnosed with pathological stage II or III disease. Notably, our findings showed that robotic gastrectomy was an independent positive predictor for recurrence-free survival in patients with pathological stage II/III [hazard ratio: 0.56 (0.33-0.96), P = 0.035]. Comparison of recurrence-free survival between the robotic and laparoscopic approach using propensity score matching analysis verified that the robotic group had less morbidity (P = 0.005). CONCLUSION: Age, ASA status, gastrectomy type, and pathological T and N status were prognostic factors of minimally invasive gastrectomy, with the robot approach possibly improving long-term outcomes of advanced gastric cancer.