Clinical Study Everolimus-Based Therapy versus Chemotherapy among Patients with HR+/HER2−Metastatic Breast Cancer: Comparative Effectiveness from a Chart Review Study

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objective. To compare the real-world effectiveness of everolimus-based therapy and chemotherapy in postmenopausal women with hormone-receptor-positive/human-epidermal-growth-factor-receptor-2-negative (HR+/HER2−) metastatic breast cancer (mBC). Methods. This retrospective chart review examined a nationwide sample of postmenopausal HR+/HER2 − mBC women in community-based oncology practices. Patients received everolimus-based therapy or chemotherapy for mBC between 07/01/2012 and 04/15/2013, after failure of a non-steroidal aromatase inhibitor. Overall survival (OS), progression-free survival (PFS), and time on treatment (TOT) were compared using Kaplan-Meier analysis and Cox proportional hazards models adjusting for line of therapy and baseline characteristics. Results. 234 and 137 patients received everolimus-based therapy and chemotherapy. Patients treated with everolimus-based therapy tended to have less aggressive mBC than patients treated with chemotherapy. Multivariate-adjusted Cox models showed that everolimus-based therapy was associated with significantly longer OS [hazard ratio (HR)