Abstract
In Kazakhstan, breast cancer (BC) remains the leading cause of cancer morbidity and mortality among women. The presented case series aims to summarize cardiovascular events that resulted in anthracycline-based chemotherapy discontinuation or suspension during the ongoing project on studying the cardiotoxicity effects. Case 1. Classic acute cardiotoxicity with asystole. Patient Sh., 46 years old, was admitted with a baseline LVEF of 64% and GLS of 22.4%. After the first dose of doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2, the patient experienced two episodes of asystole. She was prescribed Trimetazidine at a dose of 80 mg. Eventually, Sh. completed the courses of anthracycline therapy after a 1-month delay at a cumulative dose of 455 mg/m2. Case 2. Subacute cardiotoxicity with ventricular extrasystole. Patient Zh., aged 47, developed single, paired, and group ventricular extrasystoles after the 2nd course of chemotherapy with doxorubicin 200 mg/m2 (23 days after admission). Carvedilol was prescribed at 25 mg twice daily and Trimetazidine at 80 mg once a day. After 1 month of monitoring, ventricular extrasystoles disappeared. With a month’s delay, the patient completed chemotherapy at a cumulative dose of 400 mg/m2. Case 3. Severe cardiotoxicity due to pre-existing cardiovascular disease with discontinuation of chemotherapy. Patient M., aged 58, was referred to the very highrisk group for developed atrial fibrillation and heart failure with LVEF 51%. M. received Enalapril 5 mg two times per day, Bisoprolol 5 mg, Eplerenone 50 mg, Dapagliflozin 10 mg, and Dabigatran 150 mg twice daily. After 3 months, anthracycline therapy was canceled at a cumulative dose of 260 mg/m2 due to the deterioration of the patient’s condition (LVEF 41%.). Discontinuation or the delay of vitally needed chemotherapy in BC patients deteriorate their prognosis for survival. Patients should be constantly monitored during and after anticancer treatment.