[Long-term oncological safety of robotic total gastrectomy for locally advanced proximal gastric cancer: a 5-year noninferiority comparison based on the FUGES-014 study].

Objective: To report the 5-year survival outcomes and recurrence patterns of robotic total gastrectomy (RTG) for locally advanced proximal gastric cancer in order to provide more valuable long-term follow-up results for clinical practice. Methods: This was a prospective, single-arm, open-label clinical trial (FUGES-014; Clinical-Trials.gov, NCT03524287). Patients with locally advanced proximal gastric cancer who underwent RTG at Fujian Medical University Union Hospital from March 5, 2018, to February 10, 2020, were included in the analysis. To evaluate the long-term efficacy of RTG in the most objective manner possible, we performed a propensity score-matched (1∶2) comparative analysis with historical control patients who had undergone laparoscopic total gastrectomy (LTG) from the FUGES-002 study (ClinicalTrials.gov, NCT02333721) in which the 5-year disease-free survival (DFS), 5-year overall survival (OS), and recurrence patterns were compared between the two groups. Results: Prior to matching, there were 48 cases in the RTG group and 263 cases in the LTG group; patients in the LTG group had more advanced cT and pT stages (P=0.044 and 0.006, respectively) compared to the RTG group. After matching, there were 48 cases in the RTG group and 96 cases in the LTG group; however, no statistically significant differences were observed in the baseline clinical characteristics between the two groups (all P>0.05). Both groups had a median follow-up of 72 months. The 5-year DFS rates were 75.0% (95%CI: 63.7%- 88.3%) in the RTG group and 61.4% (95%CI: 52.5%-72.0%) in the LTG group (P=0.116). Similarly, the 5-year OS rates were 79.2% (95%CI: 68.5%-91.5%) and 64.6% (95%CI: 55.7%-74.9%) in the RTG and LTG groups, respectively (P=0.100). Within 5 years after surgery, tumor recurrence occurred in 10 patients (20.8%) in the RTG group and 33 patients (34.4%) in the LTG group (P=0.124), and peritoneal recurrence was the predominant pattern in both groups (8.3%[4/48] vs. 10.4%[10/96]; risk difference: -0.02,P=0.554). Gastric cancer-related death was the predominant cause of death in both groups (16.7% [8/48] vs. 31.2% [30/96]; risk difference: -0.15, P=0.064). Among patients stratified by different pathological stages, no statistically significant differences were found in DFS, OS, or recurrence rates between the RTG and LTG groups (all P>0.05). Conclusions: We find the long-term oncological outcomes of RTG for locally advanced proximal gastric cancer to be noninferior to those of LTG. RTG should therefore be considered as a valid option for standardized minimally invasive surgery for locally advanced proximal gastric cancer.