Abstract PO4-09-11: Predictors of Cardiotoxicity in Early Breast Cancer Patients Treated with Doxorubicin and/or Trastuzumab: Implications of Race/Ethnicity and Insurance Status
Authors: Jahangier Shahzaad , Qamar Rubina , Thohan Vinay , Singh Maharaj , Liao Yunqi , Weese James , Khandheria Bijoy , Kamke-Jordan Anna 
Published: May 2024

Abstract
Predictors of Cardiotoxicity in Early Breast Cancer Patients Treated with Doxorubicin and/or Trastuzumab: Implications of Race/Ethnicity and Insurance Status
Shahzaad K Jahangier, MD, Yunqi Liao, MS, Maharaj Singh, PhD, James Weese, MD, Bijoy Khandheria, MD, Anna Kamke-Jordan MS, Vinay Thohan, MD, Rubina Qamar, MD
Background: Approximately 4.1 million women in the United States are living with breast cancer1. Cardiac dysfunction is a significant adverse effect of commonly used breast cancer therapies like doxorubicin (D) and trastuzumab (T). The cardiotoxicity (CTox) associated with these agents manifests as a reduction in left ventricular ejection fraction (LVEF) with or without signs and symptoms of heart failure.
Purpose: The objective of this study is to identify high-risk populations susceptible to developing CTox, with a focus on identifying individuals who could potentially benefit from the early initiation of empiric cardioprotective therapies.
Methods: We investigated the relationship of race/ethnicity, insurance status, treatment regimen and comorbidities including hypertension (HTN), hyperlipidemia (HLD), diabetes mellitus (DM), tobacco use, BMI, age, and radiation therapy on the development of CTox from D and/or T. A total of 133 newly diagnosed stage I-III invasive breast cancer patients were enrolled in a prospective clinical trial (2013-2017) and received standard of care D and/or T based systemic therapy. Echocardiogram data was collected every 6 months for two years and then based on clinical need for a total of six years. CTox was defined as a &gt;10% drop in LVEF, and/or LVEF &lt; 50%.
Results: Our study included a population of 133 patients comprising Black (22%), White (77%), and Hispanic (1.5%) individuals. Among these patients, 32 developed CTox (Black 41%, White 19%, Hispanic 50%). Of all patients, 29% had State insurance while 71% had Private insurance. Prevalence rates for comorbidities were as follows: HTN (41%), HLD (32%), DM (13%), and tobacco use (36%). In a univariate logistic regression model, race/ethnicity, HTN, insurance status, and tobacco use were most strongly associated with Ctox. When controlling for tobacco use and HTN, race/ethnicity was not significantly associated with Ctox. However, direct comparisons of levels of race/ethnicity showed that Black patients were more likely to develop Ctox when compared to White patients (OR 2.60, 95% CI = 1.01-6.65, P = 0.045). HTN patients were also more likely to develop Ctox, when controlling for ethnicity and tobacco use (OR 2.62, 95% CI = 1.10-6.43, P = 0.031).
In a separate multivariate analysis, we examined insurance as a surrogate for socioeconomic status. Having State compared to Private insurance was associated with an increased risk of developing CTox when controlling for race/ethnicity and HTN (OR 3.73, 95% CI = 1.47-9.58, P = 0.006).
Furthermore, in all models, HLD, DM, BMI, age, and radiation field were not found to be significantly associated with increased CTox.
Conclusion: In our well characterized population of patients with stage I-III breast cancer, who were prospectively followed and received standard of care systemic therapy, we observed an association between insurance status with increased risk of CTox from treatment regimen.
1Lisa Gallicchio, PhD and others, Estimation of the Number of Individuals Living With Metastatic Cancer in the United States, JNCI: Journal of the National Cancer Institute, Volume 114, Issue 11, November 2022, Pages 1476–1483
Citation Format: Shahzaad Jahangier, Rubina Qamar, Vinay Thohan, Maharaj Singh, Yunqi Liao, James Weese, Bijoy Khandheria, Anna Kamke-Jordan. Predictors of Cardiotoxicity in Early Breast Cancer Patients Treated with Doxorubicin and/or Trastuzumab: Implications of Race/Ethnicity and Insurance Status [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-09-11.