Background: Laparoscopy-assisted distal gastrectomy (LADG) is increasingly being used as an alternative to open distal gastrectomy (ODG) for gastric cancer treatment. Retrospective studies have shown equivalent survival with the two procedures, but these studies are limited by selection bias because LADG is more technically difficult than ODG. We aimed to evaluate whether LADG was non-inferior to ODG in terms of long-term survival outcomes.
Methods: We did an open-label, multicentre, non-inferiority, phase 3 randomised controlled trial at 33 institutions in Japan. Patients aged 20-80 years with histologically confirmed gastric adenocarcinoma (T1N0, T1N1, or T2[MP]N0), clinical stage I, in the middle or lower third of the stomach, Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with a body-mass index of less than 30 kg/m2, were randomly assigned (1:1) to receive ODG or LADG. Randomisation was done by telephone, fax, or with a web-based system in the Japan Clinical Oncology Group Data Center; a minimisation method with a random component was used to adjust for institution and clinical stage (IA or IB). Only study-accredited surgeons performed ODG and LADG. The primary endpoint was relapse-free survival and was analysed according to the intention-to-treat principle. The non-inferiority margin (LADG vs ODG) was set at a hazard ratio (HR) of 1·54. The trial was registered with the UMIN Clinical Trials Registry, UMIN000003319.
Findings: Between March 15, 2010, and Nov 29, 2013, 921 patients were enrolled and randomly assigned to receive ODG (n=459) or LADG (n=462). 912 (99%) participants had the assigned surgery. 5-year relapse-free survival was 94·0% (95% CI 91·4-95·9) in the ODG group and 95·1% (92·7-96·8) in the LADG group. LADG was non-inferior to ODG for relapse-free survival (HR 0·84 [90% CI 0·56-1·27]), p=0·0075). The most common grade 3 or 4 adverse event was bowel obstruction, occurring in 11 (2%) of 455 patients in the ODG group and five (1%) of 457 patients in the LADG group. There were no treatment-related deaths.
Interpretation: This trial supports the non-inferiority of LADG compared with ODG for clinical stage I gastric cancer relapse-free survival, suggesting that LADG should be considered a standard treatment option when performed by experienced surgeons.
Funding: Japan National Cancer Center, Ministry of Health, Labour and Welfare of Japan, Japan Agency for Medical Research and Development.
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