Yamada 2015.

Methods	Randomised, open‐label, multicentre phase III study
Participants	685 patients were enrolled; 343 and 342 patients were randomly assigned to SOX or CS
Interventions	"In CS, S‐1 was given orally twice daily for the first 3 weeks of a 5‐week cycle. The dose was 80 mg/day for body surface area (BSA) <1.25 m2, 100 mg/day for BSA ≥1.25 to <1.5 m2, and 120 mg/day for BSA ≥1.5 m2. Cisplatin was administered at 60 mg/m2 as an i.v. infusion with adequate hydration on day 8 of each cycle [9]. In SOX, S‐1 was given as the same way for the first 2 weeks of a 3‐week cycle. Oxaliplatin at 100 mg/m2 was infused for 2 h i.v. on day 1 of each cycle"
Outcomes	The primary end points were noninferiority in progression‐free survival (PFS) and relative efficacy in overall survival (OS) for SOX using adjusted hazard ratios (HRs)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Minimisation method.
Allocation concealment (selection bias)	Low risk	The randomisation sequence was generated by an independent team from the trial sponsor and investigators
Incomplete outcome data (attrition bias) efficacy	Low risk	ITT
Incomplete outcome data (attrition bias) safety	Low risk	ITT
Selective reporting (reporting bias)	Low risk	PFS, OS, tumor responses, Adverse events
Other bias	Unclear risk	"During the study period, we did not test HER2 expression in tumors and could not know its exact influence on our results. The proportion of patients who received trastuzumab after the study treatment was small (<10%) and similar in both groups. Therefore, trastuzumab treatment would not seem to impact on comparing OS between both groups." "Patients who were alive and free of progression (i.e. second‐line treatment was started due to any cause) were regarded as censored cases at the date of the last assessment" "In February 2011, it appeared to be difficult to achieve the required number of events within the preplanned timetable, and the target number of patients was revised to 680 according to the predefined procedure in the protocol"
Blinded review of CT/MRI‐scans?	Low risk	"All images for PFS and tumor responses were reviewed by an independent review committee, according to the Response Evaluation Criteria In Solid Tumors (RECIST) version 1.0"