Phase II trial of chemoradiotherapy with S-1 plus cisplatin for unresectable locally advanced head and neck cancer (JCOG0706)

We conducted a phase II study to evaluate the efficacy and safety of chemoradiotherapy concurrent with S-1 plus cisplatin in patients with unresectable locally advanced squamous cell carcinoma of the head and neck. Chemotherapy consisted of S-1 twice daily on days 1–14 at 60 mg/m(2)/day and cisplatin at 20 mg/m(2)/day on days 8–11, repeated twice at a 5-week interval. Single daily radiation of 70 Gy in 35 fractions was given concurrently starting on day 1. For patients achieving an objective response after chemoradiotherapy, two additional cycles of chemotherapy were administered. Of the 45 enrolled patients, the percentage of clinical complete remission, the primary endpoint, was 64.4% (8 complete response, 21 good partial response) on central review. After a median follow-up of 3.52 years, 3-year local progression-free survival was 62.2%, with 3-year progression-free survival of 60.0%, 3-year overall survival of 64.4%, and 3-year time to treatment failure of 48.9%. Grade 3 or 4 toxicity included pharyngeal mucositis (46.7%), oral mucositis (44.4%), dysphagia (46.7%), anorexia (42.2%), radiation dermatitis (26.7%), neutropenia (26.7%), and febrile neutropenia (4.4%). No treatment-related deaths were observed. This combination showed promising efficacy with acceptable toxicities.