Cardiac tolerability of trastuzumab in metastatic breast cancer (MBC) patients previously treated with high-dose chemotherapy (HDC) with autologous hemopoietic support: Retrospective analysis from Gruppo Italiano Trapianto Midollo Osseo (GITMO) Solid Tumor Working Party

10558 Background: HER-2 overexpression is associated to a poor prognosis in high-risk and MBC patients treated with HDC. HER-2 status is also a predictive factor of response to trastuzumab: when trastuzumab is administered in combination with or sequentially to chemotherapy, a significant DFS and/or survival improvement has been observed in HER2+ early and MBC. Unfortunately, in both settings, trastuzumab was associated with an increased risk of cardiac dysfunctions (CD). Patients and Methods: In order to evaluate the cardiac safety of trastuzumab after HDC, we have reviewed the clinical charts of HER2-overexpressing MBC patients treated with HDC and trastuzumab at 11 centres of the GITMO group. Age, baseline LVEF, radiation therapy on cardiac area, exposure to anthracycline, single or multiple transplant, high-dose agents, trastuzumab treatment duration were recorded as potential risk factors. Cardiac dysfunction (CD) was defined as: 1) decline of LVEF ≥ 10% to below 50%, 2) decline of LVEF between 5 and...