A prospective phase II trial of S-1 and cisplatin-based chemoradiotherapy for locoregionally advanced esophageal cancer

Abstract

S-1 is a novel oral fluoropyrimidine anticancer agent designed to enhance clinical efficacy, reduce gastrointestinal toxicity, and enhance radiotherapy effectiveness. A phase II trial was conducted to evaluate the efficacy and safety of preoperative chemoradiation with S-1 and cisplatin in locoregionally advanced esophageal cancer. Eligible patients had stage IIA-IVA esophageal cancer. Patients received two cycles of S-1 (days 1-14 and days 22-35) and cisplatin (days 1 and 22) with concurrent radiotherapy (50.4 Gy total; 1.8 Gy/fraction). Esophagectomy was performed between weeks 12 and 18 as determined by the specialist multidisciplinary team. Sixty patients were enrolled in this study between March 2008 and August 2011, and 59 were eligible. The clinical stage was ≥T3 in 28 patients (47 %) and N1 in 43 patients (72 %), with squamous cell carcinoma histology in 58 patients (97 %). Fifty-four patients (90 %) completed the planned chemoradiation. After chemoradiation, the clinical tumor response rate was 64.4 %. The primary toxicities included neutropenia (24 %) and esophagitis (8.5 %). Three treatment-related deaths were noted. Twenty-five patients (42 %) underwent esophagectomy following chemoradiation, and 15 achieved complete pathologic regression. The estimated overall survival and progression-free survival rates after 2 years were 65 and 48 %, respectively. Concurrent chemoradiation with S-1 and cisplatin exhibited encouraging results with complete pathologic regression. The survival data were promising compared with the historical data of 5FU/cisplatin and should be confirmed in a randomized phase III trial. Toxicities were significant but clinically manageable.