Abstract C124: Breast density and metabolic risk factors: Cross-sectional analysis of the baseline data from a phase II breast cancer prevention trial
Authors: Trujillo Jesse , Tapia Edgar , Villa-Guillen Diana , Chalasani Pavani , Thomson Cynthia , Altbach Maria , Galons Jean-Phillipe , Martinez Jessica , Roe Denise , Algotar Amit , Chow H.H. Sherry 
Published: August 2020

Breast density is an established breast cancer risk factor. Metabolic disturbances and high adiposity also increase breast cancer burden, but their relationships with breast density are not clearly defined, possibly due to the limitation of mammography density measurements in obese women. We are presently conducting a phase II double-blind, randomized, placebo-controlled clinical trial to study the effect of metformin on obesity-associated breast cancer risk in overweight and obese premenopausal women with metabolic disturbances. One hundred and fifty-one participants with a large waist (≥88 cm or ≥80 cm for Asian Americans and individuals with PCOS) and one other component of metabolic syndrome (elevated triglyceride, reduced HDL-C, elevated blood pressure, or elevated fasting glucose) were accrued and randomized (1:1) to receive metformin 850 mg BID or placebo for 12 months. The primary study endpoint is change in breast density. Secondary endpoints are changes in serum insulin, insulin-like growth factor axis, adipokines, waist circumference and body weight. Thirty-six percent of the accrued participants are Hispanics. The average body mass index, waist circumference and waist-to-hip ratio of the accrued participants are 37.8 ± 6.8 kg/m2, 110.8 ± 12.4 cm and 0.90 ± 0.07, respectively. We expect to complete our clinical trial in December 2018. We performed cross-sectional analyses of the baseline data to determine the associations between metabolic disturbances and breast density parameters acquired by fat-water MRI on noncompressed breasts. This is especially relevant in our study cohort because the compressed breast thickness is greater in obese women, which results in decreased image contrast on mammogram. Potential differences by ethnicity were explored. We showed that percent density and absolute density were not related to anthropometric measurements of adiposity for the overall cohort, with similar results by ethnicity. Having elevated fasting glucose in women with a large waist was related to a lower percent density and absolute density for the overall cohort, and the association was only observed in Hispanics. Our work is the first to compare breast density assessed by fat-water MRI by ethnicity. Further research is required to confirm our findings. Due to the rising rates of obesity in the United States, we strongly believe that this trial will have an important impact in public health, especially in minority population.

Citation Format: Jesse Trujillo, Edgar Tapia, Diana Villa-Guillen, Pavani Chalasani, Cynthia Thomson, Maria Altbach, Jean-Phillipe Galons, Jessica Martinez, Denise Roe, Amit Algotar, H.H. Sherry Chow. Breast density and metabolic risk factors: Cross-sectional analysis of the baseline data from a phase II breast cancer prevention trial [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C124.