Mattea Reinisch, MD; Sabine Seiler, MD; Tanja Hauzenberger, MD; et al.
This randomized, multicenter clinical trial assesses changes in estradiol levels in male patients with hormone receptor–positive breast cancer after treatment with aromatase inhibitor plus gonadotropin-releasing hormone analogue, with gonadotropin-releasing hormone analogue plus tamoxifen, or with tamoxifen alone.