168 - Cardiac Effects of Combination Trastuzumab and Pertuzumab Therapy

Abstract

Background: Trastuzumab therapy given in combination with chemotherapy regimens is standard of care for the treatment of early-stage, human epidermal growth factor receptor-2 (HER2) -positive breast cancer. Pertuzumab, a HER2-dimerization inhibitor, has demonstrated efficacy in combination with trastuzumab. While most clinical trials report low incidence (0.5–1.1%) of cardiotoxicity, defined as asymptomatic decline of Left Ventricular Ejection Fraction (LVEF) >10 absolute points, LVEF below 50%, or decline in LVEF to <50% with heart failure symptoms, individual centers may have higher incidences. In a single center over 6 month period, we characterized the cardiac status of 9 patients treated with trastuzumab and pertuzumab. Results: In a single center, we characterized the cardiac effects of 9 breast cancer patients treated with trastuzumab and pertuzumab. Our patients ranged from 29 to 63 years old with a mean of 47.6 years. Comorbidities included 2 patients with hypertension, 2 patients with hyperlipidemia and 3 patients with obesity. None were smokers. 2 had a family history of heart failure. None were on cardio protective therapy prior to chemotherapy. During chemotherapy, 55.6% of patients had a decline in LVEF or new wall motion abnormality. 4 patients had a decline in LVEF by greater than 10%. The decline in LVEF ranged from 13 to 15% with an average decline in LVEF of 14.5%. 1 patient had a preserved LVEF but a new focal wall motion abnormality. Troponin I elevations above the upper limit of normal (0.034 ng/ml) were detected in 44.4% of patients. The average troponin elevation was 0.0955 ng/ml. Troponin levels normalized in 3 patients. 1 patient had persistently elevated troponins. Conclusions: Reports of cardiotoxicity and decline in LVEF are low in clinical trials of breast cancer patients treated with trastuzumab and pertuzumab. Our single center study highlights that both elevated troponin-I and asymptomatic decline in LVEF are common. Patients with elevated Troponin-I or decline in LVEF should be followed closely for long-term effects and heart failure therapy. As more patients are surviving a diagnosis of breast cancer, better understanding and earlier detection of therapy-induced cardiac toxicity is of paramount importance.