Canadian Study Suggests Increased Risk of Cardiac Dysfunction With Trastuzumab-Based Regimens for Breast Cancer
In a Canadian retrospective population-based cohort study reported in the Journal of Clinical Oncology, Thavendiranathan et al found that trastuzumab (Herceptin)-based regimens were associated with an increased risk of treatment-related cardiac dysfunction among women with breast cancer, with an age distribution representative of routine clinical practice.
Study Details
The analysis included 18,540 women receiving chemotherapy for stages I to III breast cancer at 14 regional cancer centers in Ontario, Canada, between 2007 and 2012. Cancer treatment was categorized as anthracycline-based chemotherapy without trastuzumab, trastuzumab with nonanthracycline chemotherapy, anthracycline followed by trastuzumab (sequential therapy), and chemotherapy without anthracycline/trastuzumab (“other chemotherapy”). The primary outcome was a composite of hospitalization or emergency room visit for congestive heart failure, outpatient diagnosis of congestive heart failure, or cardiovascular death. Patients had a median age of 54 years, with 79% being younger than age 65.
Cardiac Outcomes
At 3 years of follow-up, the cumulative incidence of the primary outcome was 3.08% among all breast cancer patients, compared with 0.96% in an age-matched cohort of 92,700 Ontario women without breast cancer. Compared with women receiving “other chemotherapy,” there was a higher risk of the primary outcome among those patients receiving trastuzumab with nonanthracycline chemotherapy (hazard ratio [HR] = 1.76, 95% confidence interval [CI] = 1.19–2.60) and those receiving sequential anthracycline followed by trastuzumab (HR = 3.96, 95% CI = 3.01–5.22). Risk of hospital-based congestive heart failure events was increased only among patients receiving sequential therapy (HR = 1.86, 95% CI = 1.07–3.22).
The investigators concluded: “In women with breast cancer and an age distribution representative of routine clinical practice, trastuzumab-based regimens, including those without anthracyclines, were associated with an increased risk of cardiotoxicity. Sequential therapy increased the risk of hospital-based congestive heart failure events.”
The study was supported by the Heart and Stroke Foundation of Canada, the Canadian Institutes of Health Research, and the Ontario Ministry of Health and Long-Term Care.
Paaladinesh Thavendiranathan, MD, of the Toronto General Hospital, University of Toronto, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
