Surgery remains the primary curative treatment for gastric cancer, with laparoscopic gastrectomy (LG) established as a standard minimally invasive approach. While LG offers faster recovery than open surgery, it remains technically demanding because surgeons must operate within a confined space using rigid instruments that can amplify hand tremors. Robotic gastrectomy (RG) was developed to overcome these limitations by providing greater precision, enhanced dexterity, and improved visualization. Although RG has become increasingly common, whether it delivers meaningful clinical benefits over conventional laparoscopic surgery in routine practice has remained uncertain.
In Japan, RG was approved for national insurance coverage in 2018, followed by regulatory changes that expanded access to robotic surgery and increased the number of surgeons qualified to perform the procedure. Five years later, researchers sought to determine whether these advances had translated into better outcomes for patients undergoing gastric cancer surgery. Their findings were published on May 29, 2026, in the journal Gastric Cancer .
The study was led by Professor Susumu Shibasaki from the Department of Surgery, Fujita Health University–Okazaki Medical Center, Japan, together with Dr. Koichi Suda from Fujita Health University, Dr. Hideki Endo from the University of Tokyo, Dr. Ken Shirabe from Gunma University, and colleagues. The study was conducted with the support of the Japanese Gastric Cancer Association.
To answer this question, the researchers analyzed data from Japan's National Clinical Database, identifying patients who underwent minimally invasive distal gastrectomy (DG) or total gastrectomy (TG) between January 2023 and December 2024. Using propensity score matching to account for differences between patients, they compared 9,743 matched pairs of robotic and laparoscopic DG cases, as well as 1,617 matched pairs of robotic and laparoscopic TG cases. "RG has become broadly integrated into routine clinical practice across Japan. Under these contemporary conditions, it remains essential to clarify whether RG offers tangible clinical advantages over LG," says Prof. Shibasaki.
The analysis showed that robotic procedures consistently required more operating time than laparoscopic surgery. On average, robotic DG took approximately 50 minutes longer than laparoscopic surgery, while robotic TG required nearly 70 additional minutes.
Despite the longer procedures, robotic surgery demonstrated several important clinical advantages. For both DG and TG, robotic surgery resulted in 33–40% less blood loss, a 50–65% lower likelihood of conversion to open surgery, and shorter postoperative hospital stays than laparoscopic surgery. Among patients undergoing DG, robotic surgery also reduced serious postoperative complications and intra-abdominal infections compared with laparoscopic surgery.
"Although the absolute magnitudes of these differences were small, the consistent benefits across multiple perioperative outcomes indicate that RG may achieve a level of minimal invasiveness beyond LG, which itself is a highly refined minimally invasive approach," says Prof. Shibasaki, adding that these benefits could be seen even in a large and diverse nationwide cohort.
The findings also suggest that RG has continued to improve since its introduction into routine care. Compared with an earlier nationwide study conducted before national insurance coverage was approved in 2018, the current analysis found better outcomes following robotic surgery. The researchers believe these improvements reflect ongoing advances in robotic technology, greater surgical experience, and expanded training opportunities over the past several years.
The benefits, however, were not identical across all procedures. While robotic DG significantly reduced major postoperative complications, robotic TG did not show a significant improvement in this primary outcome compared with laparoscopic surgery. According to the researchers, TG remains a more technically demanding procedure, and surgeons perform it less frequently, limiting opportunities to gain experience with robotic techniques.
Looking ahead, the researchers believe continued technological innovation and broader adoption of robotic surgery will further improve outcomes for patients with gastric cancer. "Over the next 5–10 years, these findings are expected to accelerate the widespread adoption of robotic surgery. As a result, more patients will have access to safer, higher quality surgical care, leading to better recovery, fewer complications, and improved overall outcomes," he concludes.
