Combination of Trastuzumab and Radiotherapy in the Adjuvant Treatment of Breast Cancer: A Single Center Experience and Focus on the Cardiac Safety

Background: The main toxicity of trastuzumab, is the alteration of cardiac function. The objective of this study is to examine the acute cardiotoxicity of the combination of Radiotherapy (RT) and trastuzumab in the adjuvant treatment of breast cancer. Materials and Methods: This is a retrospective study of 41 patients followed for localized breast cancer, treated by multimodal strategy combining chemotherapy, Radiotherapy and trastuzumab as adjuvant treatment in the medical oncology department at the Ibn Sina Military hospital of Marrakesh. Results: All patients underwent adjuvant RT on the wall, including 17 on the left side. The median value of the Left Ventricular Ejection Fraction (LVEF) before starting treatment was 64%. The median value of the absolute decrease of LVEF, after the end of RT, was of the order of 4%. All patients received treatment with trastuzumab, during irradiation at usual doses for twelve months. Trastuzumab was stopped temporarily in seven patients, because of the fall in LVEF of more than 10%. After a median followup of 13 months, one patient developed congestive heart failure, imposing the definitive cessation of trastuzumab. Conclusion: The association RT and trastuzumab, does not appear to increase the risk of acute cardiac toxicity, whatever the irradiated side.