Patients undergoing treatment for breast cancer with trastuzumab-containing regimens need to be monitored for heart damage regardless of age.1
Regimens containing trastuzumab (Herceptin) have increased survival for patients with breast cancer. Treatment with trastuzumab increases the risk of congestive heart failure, particularly when anthracyclines are used with this agent. Treatment guidelines, therefore, have recommended monitoring older patients for heart events.
This study, published in the Journal of Clinical Oncology, examined whether younger patients who received trastuzumab also need to be monitored for heart events. Researchers used health records from the Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
They evaluated treatments and outcomes for 18 540 women in Ontario with breast cancer diagnosed between 2007 and 2012. Median age of the women was 54 years, and 79% of the patients were younger than 65 years.
Researchers revealed that the adjusted rate of major cardiac events was 6.6% with anthracycline followed by trastuzumab therapy, which was almost 4 times greater than the comparison group that received other chemotherapy. Patients who received trastuzumab without anthracyclines experienced a 5.1% incidence of major cardiac events, 1.76 times greater than the comparison group. Notably, patients who received anthracyclines without trastuzumab were not at higher risk.
The large size of this study and the inclusion of patients younger than 65 years provided new data to better describe the cumulative incidence estimates between younger and older patients and with a large, age-matched cohort without breast cancer.
“Breast cancer is the most common type of cancer in Canadian women, and treatments for early stage breast cancer have proven highly effective,” stated Paaladinesh Thavendiranathan, MD, a cardiologist at the Peter Munk Cardiac Center and director of the Ted Rogers Program in Cardiotoxicity Prevention, Ted Rogers Center for Heart Research, Toronto, Ontario, Canada, and first author of the study.
“Unfortunately, some of the drugs used for the treatment of breast cancer are associated with injury to the heart and heart dysfunction. If you look at the clinical trials, which were used to approve these drugs, the risk of heart dysfunction was not very high. But when these drugs are used in clinical practice, they’re used on a broader cohort of patients and some of these patients had a higher risk of heart dysfunction.”
1. Thavendiranathan P, Abdel-Qadir H, Fischer HD. Breast cancer therapy-related cardiac dysfunction in adult women treated in routine clinical practice: a population-based cohort study [published online ahead of print April 18, 2016]. J Clin Oncol. doi:10.1200/JCO.2015.65.1505.