Fabian CJ, Nye L, Powers KR, et al. - Via performing a pilot study with 6 months of the tissue selective estrogen complex bazedoxifene (20 mg) and conjugated estrogen (0.45 mg; Duavee), researchers sought to assess their feasibility and effects on risk biomarkers for postmenopausal breast cancer. Fully automated mammographic volumetric density (Volpara), benign breast tissue Ki-67 (MIB-1 immunochemistry), and serum levels of progesterone, IGF-1, and IGFBP3, bioavailable estradiol and testosterone, were the included risk biomarkers. Enrollment of 28 perimenopausal and postmenopausal women who were at increased risk for breast cancer was performed; they enrolled 13 in cohort A with baseline Ki-67 < 1% and 15 in cohort B with baseline Ki-67 of 1% to 4%. They observed significant changes in biomarkers, uncorrected for multiple comparisons, which comprised a decrease in mammographic fibroglandular volume; decreases in serum progesterone, bioavailable testosterone, and IGF-1, an increase in serum bioavailable estradiol, and for women from cohort B a reduction in Ki-67. In addition, they observed an improvement in median hot flash score from 15 at baseline to 0 at 6 months, and menopause-specific quality-of-life total, vasomotor, and sexual domain scores.