Rodriguez GC, et al. - Researchers sought to demonstrate progestin-activation of surrogate endpoint biomarkers related to cancer prevention in the genital tract of women at increased risk of ovarian cancer to gain additional preclinical evidence backing progestins as cancer chemopreventives. They examined 64 women who received risk-reducing bilateral salpingo-oophorectomy (BSO) and received the progestin levonorgestrel or placebo for 4-6 weeks before undergoing BSO. No significant alterations in apoptosis or expression of the TGF-β1, 2, or 3 isoforms, were noted with levonorgestrel, as seen in both the ovary and fallopian tube. A significant reduction in the proliferation index was seen with levonorgestrel treatment, as noted in the ovarian epithelium. Based on karyometric data, the possible clearing of genetically abnormal cells by progestins as well as their function as chemopreventive agents against ovarian and fallopian tube cancer was further supported.