San Antonio Breast Cancer Symposium – December 6-10, 2016 Aromatase inhibitors and endothelial function: is there an association with early cardiovascular disease? Anne Blaes, M.D., M.S., Heather Beckwith, M.D., Robert Hebbel, M.D., Anna Solovey, Ph.D., David Potter, M.D., Ph.D., Douglas Yee, M.D., Rachel Vogel, Ph.D., Russell Luepker, M.D., M.S., Daniel Duprez, M.D., Ph.D. Aromatase inhibitors and endothelial function: is there an association with early cardiovascular disease? This presentation is the intellectual property of the author/presenter. Contact blaes004@umn.edu for permission to reprint and/or distribute.

No disclosures This presentation is the intellectual property of the author/presenter. Contact blaes004@umn.edu for permission to reprint and/or distribute.

San Antonio Breast Cancer Symposium, December 6-10, 2016 Background Adjuvant aromatase inhibitor (AI) therapy reduces breast cancer-related mortality in women with operable estrogen receptor (ER)-positive disease Given these women live longer due to excellent therapies, it is imperative we have an understanding of the long term complications from these prescribed therapies, weighing the potential benefit of AIs with the associated risks The incidence of cardiac events in the adjuvant trials such as MA-17, MA- 17R, ATAC and IES ranges from 3-17%, though this data is not collected consistently across the trials More recently, particularly in aging populations and in those with preexisting cardiac risk factors, patients were more likely to die of cardiovascular disease as opposed to breast cancer This presentation is the intellectual property of the author/presenter. Contact blaes004@umn.edu for permission to reprint and/or distribute.

San Antonio Breast Cancer Symposium, December 6-10, 2016 Cardiac risk factors Multifactorial etiology with a variety of widespread risk factors: obesity, sedentary lifestyle, diabetes, tobacco use, hypertension, hyperlipidemia Variety of mathematical models and risk scores to predict cardiovascular risk: Framingham risk score, Systematic coronary risk evaluation score Endothelial dysfunction using Endo-PAT has been associated with an increased risk of cardiac adverse events, independent of Framingham risk score. Those with Endothelial dysfunction by EndoPAT (RHI < 1.67) at the time of initial enrollment in a cohort study and considered low risk by Framingham data, and followed for ten years: 39% major cardiac events as compared to 25% with normal endothelial function (p=0.024) This presentation is the intellectual property of the author/presenter. Contact blaes004@umn.edu for permission to reprint and/or distribute.

San Antonio Breast Cancer Symposium, December 6-10, 2016 Methods Hypothesis: Women prescribed aromatase inhibitors will have decreased endothelial function when measured by EndoPAT Cross-sectional study at the University of Minnesota in 2014-2015 25 healthy postmenopausal women (controls); final analysis on 20 women due to exogenous estrogen use in 5 subjects 36 postmenopausal women with locally advanced, curative intent breast cancer and prescribed an aromatase inhibitor (breast cancer survivors) Subjects with a history of tobacco use, hypertension or hyperlipidemia were excluded Consented subjects underwent biomarker analysis and pulse wave analysis using the HDI/Pulse Wave CR-2000 Cardiovascular Profiling System and pulse contour analysis using the Endo-PAT2000 system. Large artery elasticity Small artery elasticity EndoPAT ratio This presentation is the intellectual property of the author/presenter. Contact blaes004@umn.edu for permission to reprint and/or distribute.

Baseline Characteristics The vast majority of our subjects were Caucasian (>90%) with no personal history of heart disease (>90%). Breast cancer cases had a mean age of 61 years, a BMI of 27 and a mean SBP of 128.6 mmHg Controls were slightly younger at 59 years with a BMI of 26 and mean SBP 116 mmHg. The vast majority of cases had stage 1,2 cancer. About half received chemotherapy 2/3 received radiation. Most cases were on anastrazole or letrozole. 7/36 cases has received prior tamoxifen use.

San Antonio Breast Cancer Symposium – December 6-10, 2016 Endothelial function   Breast Cancer Survivors Control Measure  N Median (Range) p-value LAE (ml/mmHg x 10) 36 12.9 (5.4,22.2) 20 14.6 (9.4,24.6) 0.12 SAE (ml/mmHg x 10) 5.2 (1.8,15.6) 7.0 (2.4,15.7) 0.07 EndoPat Ratio 0.8 (0.2, 2.6) 2.7 (1.3,3.8) <0.0001 LAE p=0.12 SAE p=0.07 EndoPat Ratio p<0.0001 In looking at endothelial function ,there was a trend towards a reduced endothelial function examining LAE and SAE. In examining the EndoPat ratio, cases had a statistically significant reduced ratio at 0.8 while controls measured 2.7, meeting statistical significance with a pvalue of < 0.0001. When adjusting for systolic blood pressure, this difference was still seen with a p value < 0.0001 Breast Cancer Controls Breast Cancer Controls Breast Cancer Controls *When adjusting for SBP, differences in endoPAT ratio persisted with p < 0.0001

Biomarkers: Hemostatic markers such as plasminogen activator inhibitor 1, tissue type plasminogen activator and ddimer were all increased in cases. In looking at endothelial markers, there was no difference in circulating endothelial cells. There was an increase in surface VCAM and P-selectin in cases as compared to controls, though this did not meet statistical significance. We then looked at the association between vascular function and cancer treatment characteristics. We did not see any differences when looking at use of chemotherapy, radiation or side of breast cancer treatment. Use of anastrazole appeared associated with a significant reduction in LAE as compared to exemestane and letrozole (p=0.03) There was no association between length of time on an AI and endoPAT ratio

San Antonio Breast Cancer Symposium – December 6-10, 2016 Conclusion Postmenopausal women with breast cancer on AIs have reductions in endothelial function, a predictor of adverse cardiovascular disease (acute coronary syndrome, chest pain, myocardial infarction, cardiac death) independent of the duration of AI use compared to normal healthy postmenopausal women With the growing trend that longer duration of endocrine therapy is needed, further work is needed to confirm these findings. Other studies have suggested the future cardiovascular risk may be even greater in women with a previous diagnosis of CV disease; further work is needed in this area Prospective breast cancer trials need better biomarkers to predict cardiovascular risk on chronic AI therapy This presentation is the intellectual property of the author/presenter. Contact blaes004@umn.edu for permission to reprint and/or distribute.