Consecutive daily low-dose S-1 adjuvant chemotherapy after radical treatment for squamous cell carcinoma in head and neck cancer.

CONCLUSION: Consecutive daily low-dose S-1 therapy was less toxic and its efficacy was not inferior to the conventional administration schedule. Consecutive daily low-dose S-1 chemotherapy appears to be a treatment option for patients in whom it is difficult to continue the conventional administration schedule of S-1 due to adverse events. OBJECTIVE: To evaluate the safety and efficacy of consecutive daily low-dose S-1 therapy in an adjuvant setting. METHODS: This study investigated 52 patients with absence of local residual tumor, lymph node metastasis or distant metastasis after radical treatment for advanced head and neck squamous cell carcinoma. After receiving informed consent from patients, half of the usual dose of S-1 was administered daily for 2 years. The safety, feasibility, and efficacy of this approach were evaluated. RESULTS: Hematologic toxicity was seen in 51 of 52 patients (98.1%), but grade 3 hematologic toxicity was found in only 2 patients (3.8%). Nonhematologic toxicity was observed in 15 patients (28.8%) and all were grade 1. Forty-three patients (82.7%) were able to complete the chemotherapy for 2 years without dose reduction. The 3-year disease-free survival rate and 3-year survival rate were 82.6% and 94.0%, respectively.