Randomized controlled phase III trial to investigate superiority of robot-assisted gastrectomy over laparoscopic gastrectomy for clinical stage T1-2N0-2 gastric cancer patients: Japan Clinical Oncology Group study JCOG1907 (MONA LISA study).
Authors: Rie Makuuchi, Mitsumi Terada, Junki Mizusawa, Masanori Tokunaga, Kei Hosoda, Toshiyasu Ojima, Takeshi Omori, Kazuhisa Ehara, Masaya Watanabe, Akinori Takagane, Yasunori Nishida, Yoshitomo Yanagimoto, Narikazu Boku, Takaki Yoshikawa, Masanori Terashima
Journal: Journal of Clinical Oncology (2021)

TPS254 Background: Postoperative complications reportedly affect oncological outcomes in various cancers according to the timing of adjuvant chemotherapy and by influencing the immune function. Particularly, postoperative intra-abdominal infectious complications, including intra-abdominal abscess, pancreatic fistula, and anastomotic leakage, have been identified as prognostic factors for gastric cancer. Given the negative impact of such complications on patient survival, considering the short- and long-term outcomes, it is important to develop surgical procedures with fewer complications. In Japan, laparoscopic gastrectomy is a standard treatment modality for early gastric cancer. Randomized controlled trials have shown that laparoscopic gastrectomy is relatively less invasive and has similar postoperative complications and non-inferior patient survival rates when compared with open gastrectomy. However, several challenges associated with the procedure need to be overcome, such as the limited movement of the forceps. Robot-assisted gastrectomy allows surgeons to perform more meticulous surgical interventions with articulated devices; therefore, reducing the possibility of postoperative complications, as demonstrated by a few prospective studies performed in Japan. However, a non-randomized controlled trial conducted in Korea reported that there were no benefits of robot-assisted gastrectomy in terms of postoperative complications. Furthermore, no randomized controlled trials have directly compared robot-assisted and laparoscopic gastrectomy to provide solid evidence regarding the merits of the former. Methods: To confirm the superiority of robot-assisted gastrectomy over laparoscopic gastrectomy for patients with cT1-2N0-2M0 gastric cancer, we designed JCOG1907 (UMIN000039825) as a multicenter randomized phase III trial. In the standard arm, we performed laparoscopic gastrectomy with lymphadenectomy, while in the experimental arm, we performed robot-assisted gastrectomy with lymphadenectomy. The primary endpoint is the incidence of postoperative intra-abdominal infectious complications of Clavien–Dindo classification grade ≥II. Major secondary endpoints are relapse-free survival, overall survival, overall postoperative complications, and short-term clinical outcomes after gastrectomy. The planned sample size is 1040 participants, with a one-sided alpha of 5% and a power of 70%, with an expected 3% decrease in postoperative intra-abdominal infectious complications (6% vs. 3%). Over the period of 5 years, patients will be enrolled from 35 Japanese institutions. Enrollment has started in March 2020, and as of August 2020, 30 patients have already been enrolled. Clinical trial information: UMIN000039825.