Cardiac Effects of Trastuzumab Therapy in Patients With HER2-Positive Breast Cancer
The addition of trastuzumab to adjuvant chemotherapy did not seem to negatively impact cardiac function, cardiac symptoms, or health-related quality of life in women with HER2-positive breast cancer. The potential risks of cardiac toxicity associated with trastuzumab led Patricia Ganz, MD, of the University of California Los Angeles, and colleagues, to investigate the presence of potential lasting cardiovascular impacts of the treatment. Their findings, which were published in the Journal of Clinical Oncology, may reassure many women and their oncologists about the long-term safety of trastuzumab.
Both physiologic and qualitative measurements, including left-ventricular ejection fraction (LVEF) by multigated acquisition scan as well as patient-reported outcomes on quality of life (using the Duke Activity Status Index [DASI] and Medical Outcomes Study questionnaire), were taken from disease-free patients from the NSABP Protocol B-31. After a median follow-up of 8.8 years, 95.3% of the 297 patients assigned to trastuzumab therapy had LVEF of at least 50%. Two patients in the trastuzumab group (0.6%) had LVEF up to 40%.
Furthermore, lower DASI scores correlated with age, use of medications for hypertension, cardiac conditions, diabetes, and hyperlipidemia. However, these lower DASI scores did not appear to correlate with trastuzumab adjuvant therapy.