Phase II study of concurrent chemoradiotherapy with S-1 in patients with stage II (T2N0M0) squamous cell carcinoma of the Pharynx or Larynx.

Objective: The goals of treatment for head and neck cancer are cure and organ-function preservation. For organ preservation, primary treatment via radiotherapy alone is thought to be insufficient for Stage II squamous cell carcinoma of the larynx, oropharynx or hypopharynx. The objective of the present study was to investigate the efficacy and safety of concurrent chemoradiotherapy with S-1 for patients with Stage II squamous cell carcinoma of the pharynx or larynx for primary organ preservation.

Methods: Previously untreated patients with Stage II squamous cell carcinoma of the larynx, oropharynx or hypopharynx received three courses of S-1 (40 or 50 mg twice a day; 2 weeks of administration followed by 1 week of rest every 3 weeks) during conventional radiotherapy (a single daily fraction of 1.8 Gy) to a total dose of 70.2 Gy. The primary endpoint was the local control rate at 3 years.

Results: From August 2009 to October 2012, 37 patients were evaluated for the study. The overall response rate was 100%. The 3-year local control rate was 89.0% (95% confidence interval, 78.9-99.2%), and the 3-year overall survival rate was 97.2% (95% confidence interval, 91.8-100%). Mucositis and dermatitis in the radiation field were the most common acute adverse events observed. The rates of Grade 3 mucositis and dermatitis were 27 and 35%, respectively. No patients experienced Grade 4 acute adverse events. The treatment completion rate was 89.2%.

Conclusion: Concurrent chemoradiotherapy with S-1 was safe and effective in improving local control for Stage II squamous cell carcinoma of the pharynx or larynx.