A phase I study of concurrent chemoradiotherapy using oral s-1 for head and neck cancer

S-1 is a novel oral anticancer agent containing a combination of two modulators and tegafur. We conducted a phase I study of concurrent chemoradiotherapy with S-1 for head and neck cancer.

S-1 was administered once daily, and radiotherapy was performed by 2 Gy/day, five days/week, for a total of 30 fractions. S-1 dosage was started at level 1 (55.3 mg/m(2)/day), and was increased to level 2 (66.7 mg/m(2)/day).

A total of 12 patients were registered. Concerning hematological toxicities, no grade ≥3 or more hematological toxicity was confirmed at any level. With regard to non-hematological toxicities, at level 2, three cases of grade 3 mucositis and two cases of grade 3 dermatitis were confirmed.

The results showed that the maximum tolerated dose was level 2 and that dose-limiting toxicity was mucositis. Having determined that the recommended dose is level 1, we have begun the phase II clinical study.