Long-term efficacy and toxicity of concurrent chemoradiotherapy with nedaplatin and S-1 for head and neck squamous cell carcinoma Publication date: Available online 5 June 2019 Source: Auris Nasus Larynx Author(s): Hiroshi Okuda, Masami Ohnishi, Hiroki Takahashi, Chiaki Takagi, Natsuki Takada, Toshimitsu Ohashi Abstract Objective The present study aimed to retrospectively analyze the long-term efficacy and toxicity of concurrent chemoradiotherapy with nedaplatin and S-1 for head and neck squamous cell carcinoma. Methods The study enrolled 53 patients (23 with stage II disease, 13 with stage III disease, and 17 with stage IV disease). S-1 was administered orally twice a day for 14 days, followed by a two-week rest period. Nedaplatin was intravenously administered on day 4. Where possible, two courses of chemotherapy were performed. Radiotherapy was started with the administration of S-1. We analyzed the clinical response, survival rate, acute adverse events, and late swallowing toxicity. Results The complete response rates for the primary tumor and neck lymph node metastases were 94.3% and 79.3%, respectively. The five-year overall survival rate was 79.5%, the five-year disease-specific survival rate was 84.8%, and the five-year relapse-free survival rate was 73.7%. The main acute adverse events were leukopenia, neutropenia, mucositis, and dermatitis. No patient had severe nephrotoxicity. Late swallowing toxicity was observed in 13 patients. Conclusions The low toxicity, and low nephrotoxicity of chemoradiotherapy with nedaplatin and S-1 have a positive impact on long-term survival. The combination of nedaplatin and S-1 can be used instead of cisplatin and 5-fluorouracil as a safer regimen, especially in patients with some complications and those requiring treatment in an outpatient setting.