Predictors and impact of second-line chemotherapy for advanced non-small cell lung cancer in the United States: real-world considerations for maintenance therapy.

Introduction: : Recent clinical trials incorporating maintenance chemotherapy into the initial treatment of advanced non-small cell lung cancer (NSCLC) have highlighted the benefits of exposing patients to second-line therapies. We, therefore, determined the predictors and impact of second-line chemotherapy administration in a contemporary, diverse NSCLC population.
Methods: : We performed a retrospective analysis of consecutive patients diagnosed with stage IV NSCLC from 2000 to 2007 at clinical facilities associated with the University of Texas Southwestern Medical Center. Demographic, disease, treatment, and outcome data were obtained from hospital tumor registries. The association between these variables was assessed using univariate analysis and multivariate logistic regression.
Results: : A total of 406 patients in this cohort received first-line chemotherapy and were included in the analysis. Mean age was 59 years, 28% were women, and 59% were white. Among these patients, 197 (49%) received second-line chemotherapy. Among those patients who had not progressed after four to six cycles of first-line chemotherapy, 67% received second-line chemotherapy. Receipt of second-line chemotherapy was significantly associated with patient insurance type (p = 0.007), number of cycles of first-line chemotherapy (p < 0.001), and receipt of prechemotherapy palliative radiation therapy (p = 0.005) but was not associated with patient age, gender, race, histology, or year of diagnosis. In a multivariate model, second-line chemotherapy administration remained associated with insurance type (p = 0.003), number of cycles of first-line chemotherapy (p < 0.001), and receipt of prechemotherapy palliative radiation therapy (p = 0.008). The number of cycles of first-line chemotherapy and administration of second-line chemotherapy were associated with overall survival in both univariate and multivariate analyses.
Conclusions: : In this unselected, contemporary, and diverse cohort of patients with advanced NSCLC, 67% of individuals whose disease had not progressed after four to six cycles of first-line chemotherapy eventually received second-line chemotherapy. Markers of socioeconomic status, symptom burden, and response to and tolerance of first-line chemotherapy were associated with receipt of second-line chemotherapy. These factors may assist in the selection of patients most likely to benefit from maintenance chemotherapy.