Background: We retrospectively evaluated the clinical characteristics and outcome of patients with stage IIIB/IV non-small-cell lung cancer (NSCLC) enrolled in first-line chemotherapy trials conducted by our group with respect to receiving or not receiving subsequent treatment.
Patients and methods: Data were collected from 634 patients with stage IIIB/IV NSCLC treated with platinum and nonplatinum agent-based first-line regimens. Patient survival was calculated from the day of registration to first-line chemotherapy trials (OS1) as well as from the day of first-line treatment failure or the initiation of second-line chemotherapy (OS2) until death. The decision for administering second-line chemotherapy was, in all cases, at the discretion of the physician. Two hundred twenty-four patients (35.3%) received second-line chemotherapy (second-line group) in the context of second-line clinical trials run by the same group, and 410 (64.7%) received best supportive care (BSC group). There were significant differences between second-line and BSC groups in terms of age, histology, early discontinuation of first-line chemotherapy, and performance status after first-line treatment.
Results: Three (1.3%) complete and 25 (11.2%) partial responses to second-line chemotherapy were observed for an overall response rate of 12.5% (95% confidence interval, 8.2%-16.8%). The median OS1 was 13 months and 7 months (P < 0.001) and the OS2, 7 months and 3 months (P < 0.001) for the second-line and BSC groups, respectively. Multivariate analysis revealed that good performance status, disease stage IIIB, response to first-line treatment, and late termination of first-line chemotherapy were significantly associated with increased survival. The administration of second-line chemotherapy was also independently correlated with better outcome.
Conclusion: The second-line chemotherapy and BSC groups represent different populations of patients with NSCLC. Factors indicative of increased probability of survival could be used to identify the subgroup of patients most likely to benefit from second-line chemotherapy.