Matthew Ellis, MB, BChir, PhD, FRCP of Baylor College of Medicine, Houston, TX discusses the design and results of the Phase III FALCON randomized trial of fulvestrant versus anastrozole for hormone receptor-positive advanced breast cancer (NCT01602380). Prof. Ellis explains that the study was designed to address the question if there is an optimal first-line endocrine therapy for patients with hormone receptor-positive advanced breast cancer who had not been treated with a hormonal agent before. According to Prof. Ellis, the results are known with respect to progression-free survival (PFS), which was the primary endpoint of the study. Patients on fulvestrant stayed on the drug in response approximately three months longer than patients on anastrozole (approximately 16 months vs 13 months). The results were statistically significant but the questions is if they are clinically significant as Prof. Ellis points out. He explains that these kinds of differences have driven clinical practice before as in the case of tamoxifen and aromatase inhibitors. Further, there were no dramatic increases in toxicity with fulvestrant. Recorded at the 2016 annual meeting of the European Society of Medical Oncology (ESMO), held in Copenhagen, Denmark.