A pilot study of adjuvant chemotherapy with carboplatin and oral S-1 for patients with completely resected stage II to IIIA non-small cell lung cancer.

Background: Adjuvant chemotherapy with platinum-based regimens for completely resected early-stage non-small cell lung cancer (NSCLC) provides overall survival benefit in several clinical trials.

Objectives: We conducted this prospective study to evaluate the efficacy and safety of adjuvant chemotherapy with carboplatin and S-1 for patients with completely resected stage II to IIIA NSCLC.

Methods: Patients with completely resected stage IIA to IIIA NSCLC were treated with four cycles of carboplatin with area under the concentration time curve of 5 mg/mL/min on day 1 plus S-1 at 80-120 mg/bodyweight per day for two weeks, followed by one-week rest as adjuvant chemotherapy. The primary endpoint was the completion rate of three cycles of the treatment. The secondary endpoints were safety and two-year survival rate.

Results: A total of 19 patients were enrolled, until the study was terminated prematurely because of fatal pulmonary embolism in two patients. The median number of treatment cycles was three (range: 1-4). The completion rate of three cycles was 78.9% (95% confidence interval [CI]: 56.6-91.4%). Two-year disease-free survival rate was 57.8%. Grade 3 or 4 hematological toxicities included neutropenia (26.2%), anemia (5.2%), and thrombocytopenia (15.7%). Grade 3 or 4 nonhematological toxicities were anorexia (10.5%) and nausea (10.5%). Febrile neutropenia developed in 5.2%. In two patients (10.5%), grade five pulmonary embolism was observed, and the causal relationship with treatment could not be denied.

Conclusions: Carboplatin and oral S-1 had modest survival benefit, but this regimen was not tolerable in an adjuvant setting because fatal pulmonary embolism occurred in two patients. Key points: Carboplatin and oral S-1 had modest survival benefit but this regimen was not tolerable. Fatal pulmonary embolism occurred in this regimen.