Phase IIA Trial of Acolbifene (20 mg) vs Low Dose Tamoxifen (5 mg) in Pre-menopausal Women at High Risk for Development of Breast Cancer
National Cancer Institute (NCI)
Summary
This phase IIA trial compares the effect of acolbifene versus low dose tamoxifen in preventing breast cancer in premenopausal women at high risk for developing breast cancer. The usual approach for patients at increased risk for breast cancer is to undergo yearly breast magnetic resonance imaging or ultrasound in addition to yearly mammogram. Premenopausal women at very high lifetime risk for breast cancer (greater than 50%) can consider preventive removal (mastectomy) of both breasts. Premenopausal women age 35 or older with a prior diagnosis of atypical hyperplasia, lobular carcinoma in situ, or an estimated 10-year risk of greater than or equal to 3% or estimated 10-year risk of greater than or equal to 2-5 times that of the average woman (depending on age) may be advised to consider five years of standard dose tamoxifen. Standard dose tamoxifen is four times the dose used in this study. Estrogen can cause the development and growth of breast cancer cells. Acolbifene and tamoxifen blocks the use of estrogen by breast cells. This study may help researchers measure the effects of acolbifene and low dose tamoxifen on markers of breast cancer risk in mammogram imaging, breast tissue, and in blood samples.
Description
PRIMARY OBJECTIVE: I. To determine if there is a difference in change in expression of the endocrine resistance gene anterior gradient 2 (AGR2) in benign breast tissue of premenopausal women at increased risk for breast cancer randomized to acolbifene 20 mg versus (vs) tamoxifen 5 mg orally daily for 6 months. SECONDARY OBJECTIVES: I. To determine if there is significant within-arm effect of 6 months of acolbifene 20 mg or tamoxifen 5 mg as assessed on the Estrogen Response Gene Index (ERGI) in benign breast tissue. II. To determine if there is significant within-arm effect of 6 months of…