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.