Eileen Dimond

Pilot Study of Daily Exemestane in Women with Endometrial Intraepithelial Neoplasia or Low-Grade Endometrial Cancer

Abstract Purpose: To evaluate exemestane, an aromatase inhibitor, as a preventive intervention for endometrial cancer. Experimental Design: This is a multicenter, single-arm, “window of opportunity” pilot study of exemestane (25 mg daily for 21–42 days) in postmenopausal individuals undergoing hysterectomy for endometrial intraepithelial neoplasia (EIN) or low-grade endometrial cancer. The primary objective is to determine the change in proliferation, measured by Ki-67 expression, in pre- and posttreatment endometrial tissue specimens. Secondary outcomes include measurement of circulating serum estradiol and progesterone levels, pathologic response, tissue biomarkers, safety, and adverse effects. Results: Forty participants were accrued to the study. The mean body mass index was 40.3 (range, 22.8–60.5, SD = 9.8). Preoperative diagnoses included EIN (n = 11, 27.5%), grade 1 endometrial cancer (n = 26, 65%), and grade 2 endometrial cancer (n = 3, 7.5%). Median Ki-67 score decreased from 40.7% [IQR (33.9, 50.3)] at baseline to 18.1% [IQR (8.8, 31.8)] at surgery, representing a median absolute change from baseline of 20.4% [IQR (−29.9, −6.7), P < 0.001]. In a matched historic control cohort, participants also had a decrease in Ki-67 score with a median absolute change from baseline of −6.7% [IQR (−12.7, −1.3), P< 0.001]. However, the decrease in Ki-67 was greater in the study participants than the historic controls, with a median difference between the groups of −13.4% [IQR (−23.3, 6.9), P ≤ 0.01]. Both tissue estrogen receptor and progesterone receptor expression declined significantly with exemestane treatment (P < 0.001). However, serum estradiol levels did not change between baseline and after treatment (P = 0.16). Conclusions: In this pilot study, exemestane demonstrated antiproliferative effects in EIN and low-grade endometrial cancer. This agent warrants further evaluation for the prevention of endometrial cancer.

Lessons from the Failure to Complete a Trial of Denosumab in Women With a Pathogenic BRCA1/2 Variant Scheduling Risk-Reducing Salpingo-Oophorectomy

Abstract Female carriers of pathogenic/likely pathogenic (P/LP) BRCA1/2 variants are at increased risk of developing breast and ovarian cancer. Currently, the only effective strategy for ovarian cancer risk reduction is risk-reducing bilateral salpingo-oophorectomy (RR-BSO), which carries adverse effects related to early menopause. There is ongoing investigation of inhibition of the RANK ligand (RANKL) with denosumab as a means of chemoprevention for breast cancer in carriers of BRCA1 P/LP variants. Through the NCI Division of Cancer Prevention (DCP) Early Phase Clinical Trials Prevention Consortia, a presurgical pilot study of denosumab was developed in premenopausal carriers of P/LP BRCA1/2 variants scheduled for RR-BSO with the goal of collecting valuable data on the biologic effects of denosumab on gynecologic tissue. The study was terminated early due to the inability to accrue participants. Challenges which impacted the conduct of this study included a study design with highly selective eligibility criteria and requirements and the COVID-19 pandemic. It is critical to reflect on these issues to enhance the successful completion of future prevention studies in individuals with hereditary cancer syndromes.