Retrospective analysis of cardiac tolerability of concurrent administration of trastuzumab and anthracycline-based regimen for breast cancer, to address one-year-term issues in LVEF.

Patients with HER2-positive breast cancer, who received paclitaxel (P) followed by epirubicin at 75 mg/m2, fluorouracil, and cyclophosphamide (FEC75) and concurrent trastuzumab (Trastuzumab Group) show good cardiac tolerability. We assessed left ventricular ejection fraction (LVEF) of these patients regularly, and compared with that of HER2-negative breast cancer patients who administered P followed by FEC100 (Standard Group), and followed for more one year, and address the longer-term issues in LVEF.We routinely assessed LVEF, at the time of initiation, after P, after FEC, and after 1 year, and compared them between 49 patients in Trastuzumab Group and 45 patients in Standard Group.In Trastuzumab Group, LVEF was reduced from the initial level (63.1%) to 60.4 at ``After FEC'' (p= 0.007), but had recovered to 60.9% at ``After 1 year''. A two-way repeated-measures ANOVA demonstrated a significant decline in LVEF level along the time course (p< 0.002), but there was no interaction revealed between time course of LVEF and treatment with or without trastuzumab (p= 0.834). In addition, there was no significant difference between groups (p= 0.386)CONCLUSIONS: P followed by FEC75 with concurrent trastuzumab could provide enough evidence of cardiac safety.