Maintenance chemotherapy could prolong overall and/or progression-free survival in advanced NSCLC. S-1 is an oral anticancer agent comprised of tegafur, 5-chloro-2,4-dihydroxypyridine and potassium oxonate. The TORG 0809 study was conducted to evaluate the feasibility and efficacy of maintenance chemotherapy of S-1 following DOC + CDDP in patients with curatively resected stage II and IIIA NSCLC.Methods
Patients received three cycles of DOC (60 mg/m2 d1) plus CDDP (80 mg/m2 d1), q3-4w, and subsequently S-1 at 40 mg/m2 twice a day for 14 consecutive days, q3w, for more than 6 months (max 1 year). The primary end point was determination of feasibility, which was defined as the proportion of patients who had completed maintenance for 8 cycles of S-1 or more. If the lower confidence interval (CI) of this proportion was 50% or more, the feasibility of the treatment was considered confirmed. The sample size was set to be 125.Results
Between June 2009 and November 2010, 131 patients were enrolled, of whom 129 patients were eligible and assessable. The median age was 63 (23–74 years); PS 0: 107, 1: 22; p-stage IIA: 19, IIB: 30, IIIA: 80; adenocarcinoma: 99, non-adenocarcinoma: 30. Of 129 patients, 109 patients (84.5%) completed three cycles of DOC + CDDP. One hundred and six patients initiated the maintenance S-1 and 66 patients (51.2%, 95% CI: 42.5–59.8) completed eight cycles or more S-1 treatment; this percentage was less than our previously defined criterion for treatment feasibility, since 32 patients terminated maintenance S-1 at three cycles or less. Grade 3/4 toxic effects during the maintenance S-1 included anemia (7.3%), neutropenia (3.7%), anorexia (3.7%), dyspnea (1.8%), infection with neutropenia of grade 0 to 2 (1.8%). Febrile neutropenia was not observed.Conclusions
The toxicity level was acceptable, although the results did not meet our criterion for feasibility.