OBJECTIVES : Metastatic breast cancer (mBCa) is the most common cancer, accounting for about 21.2 per 100,000 women per year. Everolimus when added to endocrine therapy showed antitumor activity in patients suffering from mBCa. The objective of the study is to evaluate the efficacy and safety of everolimus in the treatment of patients with mBCa.

METHODS : Literature searches were conducted in MEDLINE and the Cochrane Library. In addition, references of included studies and clinicaltrials.gov were searched for relevant studies. No language or date restrictions were imposed. Study quality of included trials were assessed using the Cochrane Risk of Bias Tool. Two authors independently selected papers, extracted and assessed quality. All randomized controlled trials (RCTs) examining the efficacy and safety of everolimus in mBCa patients were included. The primary outcomes assessed were overall survival (OS) and progression free survival (PFS). Secondary outcomes included response rate (RR), complete response (CR), partial response (PR), stable disease (SD), clinical benefit (CB), and overall discontinuation.

RESULTS : A total of 18 RCTs involving a total of 11252 patients were included in this meta-analysis. The everolimus group showed significantly improved OS (HR=0.85, 95% CI 0.71 to 1.007) and PFS (HR=0.42, 95% CI 0.31 to 0.57, central assessment; HR=0.52, 95% CI 0.41 to 0.67, local assessment) when compared to control group. However, no significant difference was observed in responses including RR, CR, PR, and CB, and SD between two groups. The overall discontinuation rate was higher in placebo compared to everolimus (RR=0.90, 95% CI 0.88 to 0.91).

CONCLUSIONS : Everolimus showed significant improvement in OS and PFS in patients with mBCa when compared to controlIn addition, everolimus was associated with lower overall discontinuation compared to control.