Evaluating the Utility of Baseline Cardiac Function Screening in Early-Stage Breast Cancer Treatment

Abstract

Background: Cardiotoxicity can be a complication of anthracycline or trastuzumab-based therapy for breast cancer patients. Screening echocardiogram (ECHO) and radionuclide ventriculogram (RVG) are often performed prior to administration of these agents to evaluate cardiac function. Limited evidence for the clinical utility of these screening tests is available. Methods: Early-stage breast cancer patients diagnosed from 2006 to 2011 (n=1067) with a baseline ECHO/RVG were identified in a single institution prospective registry. Medical record review was performed to obtain pre- and post-ECHO/RVG treatment plans, baseline ECHO/RVG results, cardiac risk factors, and cardiac events. Patients with cardiac history were excluded. ECHO/RVG abnormalities were defined as ejection fraction (EF) <55%, valvular disease, left ventricular hypertrophy, and diastolic dysfunction. Cardiac events were defined as heart failure, myocardial infarction, arrhythmia, valvular disease, or angina during or following chemotherapy. Results: Among 600 eligible patients, abnormal ECHO/RVG were observed in 13 (2.2%, 1.2%-3.7%), including 9 with baseline EF <55%. There were no detected changes in treatment plans, although more frequent cardiac monitoring was recommended for 2 patients. There were no significant differences in age, race, menopausal status, smoking history, alcohol use, body mass index, or medical comorbidities between patients with abnormal and normal results. In follow-up (mean 4.0 years, range 0-8.3), 15 patients developed cardiac events (none of whom had had abnormal baseline ECHO/RVG). Conclusions: Baseline ECHO/RVG in patients without prior cardiac history rarely yields an abnormality that prompts change in planned anthracycline and/or trastuzumab-based treatment. Moreover, few cardiac events developed in this screened population in follow-up.