Adjuvant oxaliplatin plus S-1 (SOX) with concurrent radiotherapy versus SOX alone for gastric cancer with D2 lymph node dissection and high risk factors: a randomized phase III trial

Abstract

Background: The role of adjuvant radiotherapy in patientswith radical ressected gastric cancer with D2 lymph node dissection is controversial. Patientswith high risk factors including late T stage (T4) and positive lymph nodes (N+) were likely tobebenefit from adjuvant concurrent chemoradiotherapy. This trial was designed to compare adjuvant chemoradiotherapy, oxaliplatin plus S-1(SOX) and concurrent radiotherapy, with SOX alone in gastric cancer patients withD2 lymph node dissection and high risk factors. Trial design: This study is amultiple center randomized phased III controlled trial undertaken by TheWestern Cooperative GastrointestinalOncology Group of China (WCGOG). Patients underwent R0 andD2 gastrectomy and pathologic diagnosed >=T4a or positive lymph node (N+) disease per AJCC 7th edition were enrolled in this study. Eligible patients were randomly assigned to receive adjuvant chemotherapy of SOXregimen and concurrent 3D-CRT/IMRT (50.4Gy/28f) or six cycles of SOX alone. Block randomizationwas done and stratified by disease stage. Primary endpoints are disease-free survival (DFS). Secondary endpoints are overall survival (OS), local control rate (LCR) and toxicity.