Randomized phase III trial of laparoscopy-assisted versus open distal gastrectomy with nodal dissection for clinical stage IA/IB gastric cancer (JCOG0912).

Abstract

4020 Background: The number of patients undergoing laparoscopy-assisted distal gastrectomy (LADG) has been increasing worldwide. Several retrospective studies have demonstrated equivalent survival after LADG compared to open distal gastrectomy (ODG). However, no confirmatory randomized controlled trials has been published in a peer review journal to evaluate the efficacy of LADG compared with ODG, ensuring strict surgical skill and quality control of surgery. We conducted phase III study to confirm that LADG is not inferior to ODG in efficacy. Methods: Eligibility criteria included histologically proven adenocarcinoma in the middle or lower third of the stomach; clinical stage I tumor (T1N0, T1N1, T2(MP)N0). Patients were preoperatively randomized to ODG or LADG. LADG was performed by accredited surgeon. The extent of nodal dissection was decided according to Japanese gastric cancer treatment guidelines. The primary endpoint is relapse-free survival (RFS) and the secondary endpoints are overall survival (OS), short-term clinical outcomes, and postoperative quality of life. Planned sample size was 920 patients in total, which was determined with at least 80% power, a one-sided alpha of 5%, and a non-inferiority margin for a hazard ratio of 1.54. Before the 1st interim analysis, the primary endpoint was amended from OS to RFS in 2015 because the surrogacy of RFS for OS was demonstrated and the predicted number of events for OS was smaller than expected. Results: A total of 921 patients were randomized (ODG 459, LADG 462) between Mar. 2010 and Nov. 2013. Among 921 patients, 912 patients (99%) underwent assigned surgery. Conversion to ODG was needed for 16 patients (3.5%) in LADG arm mainly due to advanced disease. 5-year RFS was 94.0% (95% CI: 91.4-95.9%) in ODG and 95.1% (92.7-96.8%) in LADG. LADG was non-inferior to ODG for RFS. (HR: 0.84 [90% CI: 0.56-1.27 ( < 1.54)], p for non-inferiority = 0.008). 5-year OS was 95.2% (92.7-96.8) in ODG and 97.0% (94.9-98.2) in LADG (HR: 0.83 [95% CI: 0.49-1.40]). Conclusions: The non-inferiority of LADG to ODG in RFS was confirmed. LADG has been established as one of the standard treatments for clinical stage I gastric cancer. Clinical trial information: UMIN000003319.