Examining cardiac toxicity in HER2-positive breast cancer patients using trastuzumab and its influencing factors at Iran Hospital

Trastuzumab is primarily utilized in the treatment of patients with human epidermal growth factor receptor 2 (HER2) positive breast cancer. This study aimed to investigate the incidence of cardiac toxicity associated with trastuzumab in HER2-positive breast cancer patients at Iran Hospital in 2023, as well as the factors influencing this toxicity. In this cross-sectional study, 200 patients diagnosed with HER2-positive breast cancer and receiving trastuzumab were included. The criteria for heart failure in this study were defined as an ejection fraction (EF) of less than 50% or a decrease of greater than 10% in EF. Descriptive statistics, the chi-square statistical test, Fisher's exact test, and logistic regression analyses were employed to assess the variables. A <i>p</i>-value of less than 0.05 was deemed statistically significant. The mean age of the participants was 51.5 ± 2.5 years. The odds ratio (OR) for the variable of anthracyclines was 1.3 (95% CI: 1.2-1.4); for opium use, the OR was 2.7 (95% CI: 0.9-8.5); for diabetes, the OR was 2.7 (95% CI: 1.2-5.9); for ischemic heart disease, the OR was 3.5 (95% CI: 1.6-7.7); and for hypertension, the OR was 4.8 (95% CI: 2.1-10.7). The OR for obesity was 1.45 (95% CI: 1.01-2.18), and the OR for age was 1.10 (95% CI: 1.01-1.12). No statistically significant association was found between opium use and cardiotoxicity (<i>p</i> = 0.07). This research contributes to the identification of factors that may predict responses to anthracyclines and the potential for cardiotoxicities. Ultimately, this information could inform the development of more personalized treatment strategies.