Randomized feasibility study of S-1 for adjuvant chemotherapy in completely resected Stage IA non-small-cell lung cancer: Results of the Setouchi Lung Cancer Group Study 0701

Objective: The aim of this multicenter study was to determine the appropriate administration schedule for S-1, an oral fluoropyrimidine, for adjuvant chemotherapy in patients with completely resected pathological-Stage IA (tumor diameter, 2-3 cm) non-small-cell lung cancer.Methods: Patients were randomly assigned to receive adjuvant chemotherapy consisting of either the 4-week oral administration of S-1 (80-120 mg/body/day) followed by a 2-week rest (Group A), or the 2-week oral administration of S-1 (80-120 mg/body/day) followed by a 1-week rest (Group B). The duration of adjuvant chemotherapy was 1 year in both arms. The primary endpoint was compliance, namely drug discontinuation-free survival, which was calculated using the Kaplan-Meier method with log-rank test.Results: Eighty patients were enrolled in this study, and 76 patients actually received S-1 treatment. The drug discontinuation-free survival rates at 1 year were 49.1% in Group A and 52.7% in Group B (P = 0.373). The means of the relative dose intensities were 55.3% in Group A and 64.6% in Group B (P = 0.237). There were no treatment-related deaths. Patients with grade 3/4 toxicities were significantly more frequent in Group A (40.5%) than in Group B (15.4%, P = 0.021). The 2-year relapse-free survival rates were 97.5% in Group A and 92.5% in Group B, and the 2-year overall survival rates were 100% in both groups.Conclusions: The feasibility showed no significant difference between the two groups among patients with completely resected Stage IA (tumor diameter, 2-3 cm) non-small-cell lung cancer.