Therapeutic advances in cancer management has signifcantly improved breast cancer patients’ survival. However, antineoplastic agents, especially anthracyclines and HER2 inhibitors, are associated with non-negligible cardiac toxicity.

To assess the incidence of anthracycline and trastuzumab induced cardiotoxicity in order to establish a standardized follow-up protocole in our unit.

We conducted a prospective longitudinal study in collaboration with the Mohemed VI center for cancer treatment in the cardio-oncology unit of Casablanca over 3 years (from January 2017 to december 2019) including all the breast cancer patients under trastuzumab and/or anthracyclines

A total of 1092 patients were included, mean age was 51±12 years (17–83) (91.2%). Menopause was the most frequent cardiovascular risk factor (CVRF) (81.2%), followed by obesity (19.2%) and hypertension (18.1%). 74.6% of our patients received anthracyclines, which were indicated as adjuvant therapy in 78,0%. 54% had a cumulative dose (CD) of adriamycin below 250mg/m² and 72% received an epirubicin CD between 300 and 500mg/m². 53.7% of our patients were under HER2 inhibitors among which trastuzumab was the most frequent (87%). 56.8% with a left breast cancer were under adjuvant radiotherapy. 96 developped cardiotoxicity with an incidence of 8.8%. Asymptomatic Left ventricular dysfunction was found in 45,8%, among which 38 patients (39,5%) recovered their initial LVEF under cardioprotective treatment, 32 of whom had a trastuzumab induced cardiotoxicity.

Our results seem comparable to litterature findings. Correction of CVRF, early diagnostis of cardiac dysfunction according to the guidelines and consequent oncologic therapy adjustment may help avoiding severe complications altering cancer patients’ quality of life and prognosis.