Cardiac tolerability of concurrent administration of trastuzumab and anthracycline-based regimen as adjuvant chemotherapy for breast cancer.

BACKGROUND Retrospective analysis suggests that anthracycline-containing regimens may be superior to non-anthracycline-containing regimens in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, both trastuzumab and anthracycline have cardiotoxicity, and it remains unclear how to use trastuzumab in combination with an anthracycline to curtail their cardiotoxicity. PATIENTS AND METHODS From 2010 to 2013, we administered weekly (q1w) paclitaxel (wP) followed by 75 mg/m(2) epirubicin, fluorouracil, and cyclophosphamide (FEC) every third week (q3w) and concurrent q1w trastuzumab (H) to 41 patients with HER2-positive breast cancer (H+ group), and wP followed by FEC100 without trastuzumab to 57 patients who were HER2-negative (H- group). We routinely assessed the left ventricular ejection fraction (LVEF) by echocardiography, at the time of initiation, after wP, and after FEC, and compared them between these 2 groups. RESULTS LVEF decreased from 63.2 to 60.9% (p = 0.030) in the H+ group and from 63.9 to 61.9% (p = 0.009) in the H- group. These 2 groups showed no significant difference in the reduction rate of LVEF over the period of chemotherapy (0.968 vs. 0.978: NS, p = 0.6457). There was no severe cardiotoxicity or congestive heart failure in either group. CONCLUSION Concurrent administration of epirubicin (q3w, 75 mg/m(2)) and trastuzumab showed no less cardiac tolerability in an adjuvant setting.