Acceptability and feasibility of S-1 plus cisplatin adjuvant chemotherapy for completely resected non-small cell lung cancer: an open-label, single arm, multicenter, phase 2 trial

BACKGROUND: Although platinum-based chemotherapy is accepted as adjuvant chemotherapy for resectable advanced non-small cell lung cancer (NSCLC), its completion rate is low due to severe adverse events. S-1 plus cisplatin is associated with relatively low toxicity and an unimpaired quality of life, and has been used for unresectable advanced lung cancer. We investigated the acceptability and feasibility of combination therapy with S-1 plus cisplatin as postoperative adjuvant chemotherapy following complete resection of pathological stage II-IIIA NSCLC. METHODS: Enrolled patients received oral S-1 at a dose depending on their body weight twice daily for 21 days with intravenous cisplatin 60 mg/m(2) on day 8, with 1 cycle comprising 5 weeks and 4 cycles. Patients received standard precautions against adverse events and received standard treatment when adverse events occurred. The primary endpoint was completion rate; secondary endpoints included safety, status of drug administration, disease-free survival (DFS), and overall survival (OS). RESULTS: A total of 19 patients [14 men, 5 women; mean age, 59.1 years; mean body surface area, 1.688 m(2); 17 with an Eastern Cooperative Oncology Group performance status (PS) of 0 and 2 with a PS of 1; 7 (36.8%) with stage II disease and 12 (63.2%) with stage IIIA disease] were enrolled. The rate of completion of 4 cycles was 68.4%. Grade 3 adverse events that occurred in ≥10% of patients included neutropenia (21.1%), nausea (21.1%), and anorexia (15.8%). No grade 4 adverse events, febrile neutropenia, or treatment-related deaths occurred. The mean relative dose intensity (RDI) was 79% for S-1 and 80% for cisplatin. The 2-year DFS rate was 42.1%, and 2-year OS rate was 83.3%. CONCLUSIONS: This study demonstrated the acceptability and feasibility of using S-1 plus cisplatin as adjuvant chemotherapy. TRIAL REGISTRATION: This study was registered on the UMIN clinical study registration site (protocol ID: UMIN000016191) on December 1, 2015.