Anastrozole and Fulvestrant in Metastatic Breast Cancer

To the Editor: Mehta et al. (Aug. 2 issue) 1 report that the combination of anastrozole and fulvestrant was superior to anastrozole alone when administered as first-line endocrine therapy to North American women with hormone-receptor (HR)–positive metastatic breast cancer. This finding differs from that of the similarly designed Anastrozole Monotherapy versus Maximal Oestrogen Blockade with Anastrozole and Fulvestrant Combination Therapy (FACT) study, in which the same combination therapy was not superior to anastrozole alone in mainly non-American Scandinavian women. 2 There is no clear explanation for this difference, which hampers the implementation of the authors' observation. They quote several plausible reasons for . . .