Analysis of feasibility and toxicity of concurrent chemoradiotherapy with S-1 for locally advanced squamous cell carcinoma of the head and neck in elderly cases and/or cases with comorbidity

Purpose The aim of this study was to evaluate the feasibility and toxicity of concurrent chemoradiotherapy (CCRT) with S-1 in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN) in elderly cases and/or cases with comorbidity. Methods Fifty eligible patients with stage III (15 cases) or stage IV (35 cases) SCCHN were treated with CCRT. Thirteen cases had an advanced age of over 75 years and 37 cases had comorbidity. Definitive radiotherapy was delivered up to a total dose of 66–70.2 Gy. The patients received two courses of oral S-1 (40 or 50 mg twice a day [80 or 100 mg/day]) for 2 weeks followed by 1 week of rest while receiving CCRT. Results All the patients received the planned radiotherapy and at least one course of S-1. Grade 3 mucositis occurred in 20% of the patients (10/50). Grade 3 neutropenia occurred in 12% (6/50) and leukocytopenia occurred in 6% (3/50) of the cases. Pathologically, the complete response rates were 93% in stage III and 54% in stage IV. Conclusion Concurrent chemoradiotherapy with S-1 is a safe, well-tolerated and effective regimen for locally advanced SCCHN in elderly cases and/or cases with comorbidity.