Fulvestrant 250mg versus Anastrozole 1 mg in the Treatment of Advanced Breast Cancer: a Meta-Analysis of Randomized Controlled Trials

Objective: Most patients with advanced breast cancer experience resistance to endocrine treatment andeventual disease progression. This meta-analysis was designed to compare the efficacy and tolerability offulvestrant 250mg with anastrozole 1mg in postmenopausal women with advanced breast cancer.
Methods:Electronic literature databases (Cochrane Library, Medline, and Embase) were searched for randomizedcontrolled trials (RCTs) published prior to August 2013. Only RCTs that compared fulvestrant 250mg toanastrozole 1mg in postmenopausal women with advanced breast cancer were selected. The main outcomeswere time to treatment failure (TTF), time to progression (TTP), duration of response (DOR), clinical benefitrate, 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 andanastrozole 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 betweenthe two groups for common adverse events.
Conclusion: Fulvestrant 250mg is as effective and well-toleratedas anastrozole 1mg treatment for advanced breast cancer in postmenopausal women whose disease progressedafter prior endocrine treatment. Thus, fulvestrant may serve as a reasonable alternative to anastrozole whenresistance is experienced in breast cancer cases.