Effect of bariatric surgery on breast tissue and biomarkers in obese women at increased risk for breast cancer.

Abstract

TPS1592 Background: Obesity represents a challenging epidemic associated with increased risk of several malignancies, including breast cancer in post-menopausal women. Proposed mechanisms for the association between obesity and breast cancer risk include increased insulin resistance, elevated levels of circulating estrogens, and chronic inflammation. Intentional weight loss from bariatric surgery has been associated with decreased risk of breast cancer. While rapid improvements in serologic markers of metabolism and inflammation are seen following bariatric surgery, short- and long- term changes in breast tissue remain less clear. This study investigates the effect of bariatric surgery on breast density and biomarkers of increased risk in breast tissue. Methods: This pilot, single institution, observational study (NCT02681120) is recruiting pre- and post-menopausal women with BMI ≥30 from a University bariatric surgery clinic using the Hughes risk application as a screening tool. Eligible patients must have a lifetime risk for breast cancer of ≥20%. Participants are evaluated by imaging, breast biopsy, and blood samples at baseline, 14 days post-operatively to determine the effects of rapid metabolic changes, and 1 year post-operatively to determine the effects of significant weight loss. The impact of bariatric surgery on known imaging parameters of breast cancer risk is assessed by background parenchymal enhancement on MRI and breast density on mammogram. Breast tissue is evaluated for changes in immune infiltrates, aromatase expression, and the presence of crown-like structures, a marker of inflammation seen in the breast tissue of obese women. Tissue samples at each time point are also compared to samples from lean women in the Susan G. Komen Tissue Bank at the IU Simon Cancer Center. Blood is collected for correlative studies evaluating markers of inflammation, insulin resistance, metabolism, and hormone synthesis. Enrollment is currently ongoing with a planned accrual of 40 patients, and data collection is estimated to complete by the end of 2018. Clinical trial information: NCT02681120.