Objective: Most patients with advanced breast cancer experience resistance to endocrine treatment and eventual disease progression. This meta-analysis was designed to compare the efficacy and tolerability of fulvestrant 250 mg with anastrozole 1mg in postmenopausal women with advanced breast cancer.
Methods: Electronic literature databases (Cochrane Library, Medline, and Embase) were searched for randomized controlled trials (RCTs) published prior to August 2013. Only RCTs that compared fulvestrant 250 mg to anastrozole 1mg in postmenopausal women with advanced breast cancer were selected. The main outcomes were time to treatment failure (TTF), time to progression (TTP), duration of response (DOR), clinical benefit rate, and tolerability.
Results: Four RCTs covering 1,226 patients (fulvestrant, n=621; anastrozole, n=605) were included in the meta-analysis. Fulvestrant increased the DOR compared to anastrozole (HR =1.31, 95% confidence interval [CI] 1.13-1.51). There was no statistically significant difference between fulvestrant and anastrozole in terms of TTF (HR=1.02, 95%CI 0.89-1.17), complete response (RR=1.79, 95%CI, 0.93-3.43), and partial response (RR=0.91, 95%CI 0.69-1.21). As for safety, there was no statistical significance between the two groups for common adverse events.
Conclusion: Fulvestrant 250 mg is as effective and well-tolerated as anastrozole 1mg treatment for advanced breast cancer in postmenopausal women whose disease progressed after prior endocrine treatment. Thus, fulvestrant may serve as a reasonable alternative to anastrozole when resistance is experienced in breast cancer cases.