Potential Advantages of Robotic Total Gastrectomy in Advanced Middle-Upper Gastric Cancer

All patients provided informed consent for the use of their clinical data at admission or prior to surgery, in accordance with the Declaration of Helsinki. The study protocol was approved by the institutional review boards of all eight participating centers and reported in accordance with STROCSS guidelines.

This multicenter registry included patients diagnosed with middle and upper gastric cancer (GC), who underwent radical total gastrectomy with pathological staging of T2-4aN0-3bM0. Exclusion criteria included ASA class >3, residual GC, neoadjuvant chemotherapy, combined organ resection, indocyanine green (ICG) use, concurrent/past malignancies, and loss to follow-up. A total of 1,099 eligible patients were included in the final analysis, with 237 receiving robotic total gastrectomy (RTG) and 862 receiving laparoscopic total gastrectomy (LTG).

To ensure surgical quality, all centers followed standardized protocols. Surgeons had completed their institutional learning curve-defined as independently performing ≥50 laparoscopic gastrectomies with consistent outcomes-before enrolling patients. RTG was performed only by certified surgeons trained in the Da Vinci Robotic System. Surgical procedures adhered to Japanese Gastric Cancer Treatment Guidelines, and pathological staging followed the AJCC 8th edition criteria. Resected specimens were evaluated by experienced gastrointestinal pathologists using uniform histopathological protocols. R1 resection was defined as microscopic tumor presence at the surgical margin.

Patient selection for RTG or LTG was based on shared decision-making, considering tumor stage, comorbidities, surgical risk, cost, and patient preference. Informed consent included agreement to cover any additional costs associated with robotic surgery.

Propensity score matching (PSM) was used to control for baseline differences between groups. A 1:1 nearest-neighbor matching with a caliper of 0.2 was performed using the MatchIt package in R. Thirteen covariates-age, sex, BMI, ASA grade, comorbidities, tumor size/location, histology, pT/pN stage, lymphadenectomy extent, adjuvant chemotherapy, and year of surgery-were included. Matching balance was evaluated using standardized mean differences (SMDs), with <0.1 considered acceptable.