Multi-institutional phase II trial of S-1 in patients with oral squamous cell carcinoma

The aim of this study was to investigate the efficacy and safety of an oral fluoropyrimidine anticancer agent, S-1, in patients with oral squamous cell carcinoma. Patients with pathologically confirmed squamous cell carcinoma and at least one measurable lesion were enrolled. Oral administration of S-1 (40 mg/m2 twice daily) for 28 days was followed by a 14-day rest period. A total of 41 consecutive eligible patients were enrolled in the study between October 2002 and August 2004. The sites of the primary tumor were the gingiva (n=18), the tongue (n=12), the palate (n=5), the oral floor (n=4), the buccal mucosa (n=1), and the labial mucosa (n=1). A median of two cycles of treatment (range, 1-5) was administered. A complete response was achieved in nine patients and a partial response in eight patients, for an overall response rate of 41.5% (95% confidence interval, 26.4-56.5%). The 3-year survival rate was 76.4% (95% confidence interval, 62.8-90.0%). Although grade 3 anemia and anorexia occurred in two patients each (4.9%), and grade 3 neutropenia, thrombocytopenia, nausea, vomiting, stomatitis, and diarrhea in one patient each (2.4%), no grade 4 toxicities were observed. S-1 exhibits definite antitumor activity in patients with oral squamous cell carcinoma and is well tolerated.