Carboplatin versus two doses of cisplatin in combination with gemcitabine in the treatment of advanced non-small-cell lung cancer: Results from a British Thoracic Oncology Group randomised phase III trial

BACKGROUND Platinum-based combination chemotherapy is standard treatment for the majority of patients with advanced non-small-cell lung cancer (NSCLC). The trial investigates the importance of the choice of platinum agent and dose of cisplatin in relation to patient outcomes. METHODS The three-arm randomised phase III trial assigned patients with chemo-naive stage IIIB/IV NSCLC in a 1:1:1 ratio to receive gemcitabine 1250 mg/m(2) on days 1 and 8 of a 3-week cycle with cisplatin 80 mg/m(2) (GC80) or cisplatin 50 mg/m(2) (GC50) or carboplatin AUC6 (GCb6) for a maximum of four cycles. Primary outcome measure was survival time, aiming to test for a difference between treatment arms and also assess non-inferiority with pre-defined margin selected as hazard ratio (HR) of 1.2. Secondary outcome measures included response rate, adverse events and quality of life (QoL). FINDINGS The trial recruited 1363 patients. Survival time differed significantly across the three treatment arms (p = 0.046) with GC50 worst with median 8.2 months compared to 9.5 for GC80 and 10.0 for GCb6. HRs (adjusted) for GC50 compared to GC80 was 1.13 (95% confidence interval [CI] 0.99-1.29) and for GC50 compared to GCb6 was 1.23 (95% CI: 1.08-1.41). GCb6 was significantly non-inferior to GC80 (HR = 0.93, upper limit of one-sided 95% CI 1.04). Adjusting for QoL did not change the findings. Best objective response rates were 29% (GC80), 20% (GC50) and 27% (GCb6), p < 0.007. There were more dose reductions and treatment delays in the GCb6 arm and more adverse events (60% with at least one grade 3-4 compared to 43% GC80 and 30% GC50). INTERPRETATION In combination with gemcitabine, carboplatin at AUC6 is not inferior to cisplatin at 80 mg/m(2) in terms of survival. Carboplatin was associated with more adverse events and not with better quality of life. Cisplatin at the lower dose of 50 mg/m(2) has worse survival which is not compensated by better quality of life. CLINICALTRIALS. GOV IDENTIFIER NCT00112710. EUDRACT NUMBER 2004-003868-30. CANCER RESEARCH UK TRIAL IDENTIFIER CRUK/04/009.