A randomized phase II trial of cisplatin plus gemcitabine versus carboplatin plus gemcitabine in patients with completely resected non-small cell lung cancer: Hokkaido Lung Cancer Clinical Study Group Trial (HOT0703).

PURPOSE: This study evaluated the efficacy and safety of platinum plus gemcitabine (P/G) combinations as postoperative adjuvant chemotherapies for non-small cell lung cancer. METHODS: Patients with postoperative stage IB-IIIA non-small cell lung cancer were randomly assigned to receive either cisplatin plus gemcitabine (GP arm) or carboplatin plus gemcitabine (GC arm) every 3 weeks for four cycles. The primary endpoint was 2-year disease-free survival (DFS). Secondary endpoints were safety, feasibility, overall survival (OS), and biomarker analyses. RESULTS: A total of 102 patients were randomized (stage IB, 22%; II, 36%; IIIA, 42%; histology: 74% adenocarcinoma). Of the 51 patients in each arm, 37 (73%) completed 4 cycles. During follow-up (median 5.8 years; range 0.1-9.7 years), estimated DFS and OS rates at 2 years were 59.6% and 86.3% with GP and 68.0% and 86.3% with GC, respectively. No significant difference in DFS was noted between arms (P = 0.163), although 3-, 4-, and 5-year DFS rates were higher with GC. Hematological toxic effects were comparable and non-hematological toxic effects were infrequent. DFS was significantly higher in the excision repair cross-complementation group 1 (ERCC1)-low group than in the ERCC1-high group for the GP arm (P = 0.045). CONCLUSION: Both P/G combination regimens were feasible and well-tolerated, and thus may represent valid options for postoperative adjuvant treatment of non-small cell lung cancer. Although no significant differences in DFS were evident between regimens, the present data favor the adoption of GC for further evaluation. CLINICAL TRIAL REGISTRATION: UMIN-CTR ( https://www.umin.ac.jp/ctr/ ) identifier: UMIN000000913.