OS and PFS were assessed as time to event from initiation of line of therapy (first-line or second-line). HR values reported are adjusted HRs calculated using multivariate Cox regression models (variables in the final adjusted multivariate analysis in the first-line chemotherapy group included age at start of line 1, race, gender, smoking history, ECOG status ≤60 days before start of line 1, and stage at initial diagnosis for OS and PFS [panels A and C]; for the second-line chemotherapy group, race, smoking history, and ECOG status ≤60 days before start of line 2 were included for OS and PFS [panels B and D]). CI: confidence interval; ECOG: Eastern Cooperative Oncology Group; HR: hazard ratio; mOS: median overall survival; mPFS: median progression-free survival; OS: overall survival; PFS: progression-free survival.