Concurrent chemoradiotherapy with S-1 as first-line treatment for patients with oropharyngeal cancer

Purpose: s-1 is an oral fluoropyrimidine. the purpose of this study was to review the clinical outcomes of s-1 with concurrent radiotherapy for patients with oropharyngeal cancer. materials and methods: between 2002 and 2007,38 patients with oropharyngeal cancer treated concurrently with s-1 and definitive radiotherapy were reviewed. the clinical stage was stage i in 4 patients,stage ii in 7,stage iii in 7,and stage iv in 20. s-1 was administered orally twice daily for 4 consecutive weeks followed by a 2-week drug withdrawal. the initial dose of s-1 was 65 mg/m2/day. all patients were treated using three-dimensional conformal radiotherapy with a median total dose of 65.1 gy (range,60.0-71.0 gy). clinical outcomes and major acute toxicities were analyzed based on medical records and clinical follow-up. results: with a median follow-up time of 33 months,the 3-year estimates of local-regional control,distant metastases-free survival,disease-free survival,and overall survival for all patients were 75%,80%,65%,and 80%,respectively. the 3-year estimates of local-regional control according to stage were 100% for stages i and ii,86% for stage iii,and 56% for stage iv. the rate of ≥ grade 3 acute mucositis was 32%,and the rate of ≥ grade 3 hematological toxicities was 8%. no other severe toxicities were observed. conclusions: concurrent chemoradiotherapy with s-1 was found to be effective,especially for early disease. the treatment-related toxicities were acceptable,and the incidence of myelotoxicity was low. further study must be carried out to compare with other chemotherapy regimens.