Dr Moslehi on Cardiac Toxicities Associated With Breast Cancer Therapies

“A small subset of patients [receiving] immune checkpoint inhibitors can have myocarditis. It’s a small number, but this myocarditis can be severe and deadly, so it’s important for us to both understand the mechanisms of myocarditis and, more importantly, identify [which patients are] at risk so we can tailor treatments accordingly.”

Javid Moslehi, MD, chief of Cardio-Oncology and Immunology at the University of California San Francisco Health, discussed the evolution of cardiac monitoring protocols within the paradigm of breast cancer therapeutics.

Moslehi began by explaining that the multidisciplinary shifts seen in precision oncology, which include the transition from established treatments to targeted and immune-based therapies, emphasize the need for more refined strategies for managing patient cardiovascular health. He noted that although traditional treatments for breast cancer, such as radiation and anthracyclines, have long-established associations with heart failure and coronary disease, the introduction of targeted therapies like trastuzumab (Herceptin) was initially met with the expectation of minimal cardiac effects. However, he said that early clinical studies revealed a significant increase in cardiac risk when trastuzumab was combined with anthracyclines. This discovery led to the current regulatory arena, where the FDA mandates that patients with breast cancer who receive trastuzumab undergo echocardiogram screenings every 3 months. Moslehi observed that although the field has largely transitioned to using trastuzumab without anthracyclines—a practice that significantly lowers the cardiac risk profile of the HER2-directed therapy—the rigorous 3-month screening schedule has persisted for 25 years. In his assessment, the frequency of these evaluations could likely be reduced for many patients if the medical community becomes more adept at identifying specific risk factors.

The discussion further extended to the monitoring requirements of newer therapeutic classes, including CDK4/6 inhibitors and immune-based treatments. For instance, Moslehi pointed out that the FDA mandates electrocardiograms in conjunction with ribociclib (Kisqali) use, due to the agent’s potential to cause heart rate alterations. Additionally, he emphasized the emerging challenge posed by immune checkpoint inhibitors, which can induce myocarditis. Although this adverse effect occurs in only a small subset of patients, Moslehi warned that the condition can be severe and deadly, making it essential to understand the underlying mechanisms and improve risk stratification.