Risk factors for developing cardiotoxicity of trastuzumab in breast cancer patients: An observational single-centre study.

BACKGROUND: Trastuzumab is a recombinant humanized monoclonal antibody used to treat human epidermal growth factor receptor 2 positive breast cancer, with recognized associated cardiotoxicity. In this retrospective observational study, we investigated associated cardiotoxicity on clinical outcomes using trastuzumab in women referred to our clinic. MATERIALS AND METHODS: The study was made up of 111 women with human epidermal growth factor receptor 2-overexpressing breast cancer who received trastuzumab in the Medical Oncology Department, between 2010 and 2013. RESULTS: A > 10% reduction of the baseline fraction of the left ventricular ejection fraction was observed in 18 (16.21%) women. Two individuals (1.8%) suffered from symptomatic heart failure, seven women showed cardiac symptoms and nine women showed asymptomatic decline of left ventricular ejection fraction. Risk factors for cardiotoxicity in the group included: postmenopausal status (p = 0.01), hypertension (p = 0.002), obesity (p = 0.0001), previously diagnosed coronary artery disease (p = 0.0001) and smoking (p = 0.03). CONCLUSION: The aforementioned factors pose a risk for cardiotoxicity. We found postmenopausal status, hypertension, obesity, previous coronary artery disease and smoking to be associated with an increased risk of cardiac dysfunction in women using trastuzumab. While administering trastuzumab to women who have these conditions, one must be aware of the risk of cardiotoxicity of trastuzumab.