The goal of this pilot study is to demonstrate that obesity is associated with worse reactive hyperemic index, a marker of vascular function, in breast cancer survivors. For this, we propose to measure and compare reactive hyperemic index in breast cancer survivors with and without obesity.
Background
Cardiovascular disease (CVD) is the leading cause of death in women, accounting for 35% of female deaths. While in the past five decades, the 5-year breast cancer (BC)-specific mortality decreased from 25% to 9%, BC survivors are dying of CVD at unprecedented rates. Compared to women who have never had cancer, postmenopausal BC survivors have a 1.5- to 2-fold greater risk of CVD mortality. This is at least partly due to the fact that some BC treatments that are critical for survival confer a higher CVD risk, and also partly due to common CVD risk factors, such as obesity. In BC survivors, obesity increases CVD risk mortality by 2.5-fold. Estimates suggest that by 2050, >60% of US adult women will be living with obesity. With a rapidly growing number of BC survivors, projected to increase from four to five million over the next decade in the US, obesity represents a target to reduce their CVD risk.
Endothelial vascular dysfunction, referred here on as vascular function, is a preclinical marker of CVD and a strong predictor of CVD mortality. Obesity is independently associated with vascular dysfunction, a result of adipokine-mediated inflammation in obesity [6]. Vascular dysfunction is also reported with anticancer treatments in BC survivors. Aromatase inhibitors (AIs), a common therapy for postmenopausal BC, for example have been linked to vascular dysfunction, via decreased levels of estrogens that are critical for CV health in women. While obesity in BC survivors may synergistically impact vascular dysfunction, no studies to date have investigated this.