GNRH1 and breast cancer: A total of 261 relatively healthy postmenopausal women (non-BrCa), 88 postmenopausal women with breast cancer receiving tamoxifen therapy (BrCa), and 59 women with breast cancer receiving both tamoxifen and a GnRH analog injection (BrCa-Gn) who fulfilled the entry criteria were enrolled in this study.