Predictors of cardiotoxicity in breast cancer patients treated with doxorubicin/trastuzumab.

Abstract

e24125 Background: Cardiotoxicity is a well-documented adverse effect of chemotherapy in breast cancer (BC) patients treated with anthracyclines such as doxorubicin and targeted therapies like trastuzumab. The development of chemotherapy-induced cardiotoxicity (CIC) can lead to significant morbidity. Understanding the predictors of CIC can help identify high-risk patients and guide monitoring strategies to mitigate this risk. Methods: We analyzed data from the 2020 National Inpatient Sample (NIS) database, the largest inpatient care database in the United States. We included patients aged 18 and older with a BC diagnosis who underwent chemotherapy, identified using ICD-10 codes. The study population with CIC was also determined. Baseline demographic information, including age, sex, race, income level, and health insurance type, as well as the prevalence of comorbid conditions such as diabetes mellitus, hyperlipidemia, obesity, and substance use were collected. We compared the prevalence of these characteristics between patients who developed CIC and those who did not, using the Wald test. A logistic regression model was applied to identify baseline characteristics and comorbid conditions associated with CIC. Sampling weights were used to ensure nationally representative estimates, and a 2-sided P < 0.05 was considered statistically significant. Results: The study included 23,055 patients with BC, of whom 140 (0.6%) developed cardiotoxicity. The study population was mostly aged 18-64 years (67.9%), were female (99.1%), white (61.8%), and had Medicare insurance (44.1%). Among the comorbid conditions, hyperlipidemia was present in 24.0% of patients, with a higher prevalence in the cardiotoxicity group (39.3% vs 23.9%, p-value = 0.113). There were no significant differences in the prevalence of diabetes and obesity in both groups (10.7% vs 10.8%, p-value = 0.994 and 3.6% vs 9.9%, p-value = 0.089, respectively). The logistic regression analysis revealed that hyperlipidemia was a significant predictor of cardiotoxicity (Odds Ratio [OR] 2.55, p-value = 0.02), increasing the odds of developing CIC by more than twice. Other factors such as age, sex, race, income, and diabetes showed no significant associations with CIC. The results for diabetes, obesity, and substance use were also non-significant. Conclusions: In this cohort of BC patients treated with doxorubicin and trastuzumab, hyperlipidemia significantly increased the odds of CIC. Other baseline characteristics, and comorbidities such as diabetes, obesity, and substance use, did not show significant associations. These findings underscore the importance of managing hyperlipidemia in patients undergoing chemotherapy for BC, as well as the need for further studies with larger sample sizes to identify predictors to prevent CIC and improve patient outcomes in this population.