Adult survivors of childhood cancer have a higher risk of mortality after major cardiovascular events as compared to adults without cancer, a new study shows. Cancer survivors also have a similar mortality risk to adults from a racially diverse adult population who experienced their first cardiovascular events at a much older age, according to the study. Wendy Bottinor, MD, MSCI, of Virginia Commonwealth University, and colleagues, reported these findings in manuscript published Monday online and in the Journal of the American College of Cardiology. Intensive therapies for childhood cancer, including chest-directed radiotherapy and anthracycline chemotherapy, are associated with an increased risk of cardiovascular toxicity in adult survivors. The investigators in this study aimed to determine the risk of mortality after a major cardiovascular event among childhood cancer survivors as compared with adults without cancer. The Childhood Cancer Survivor Study (CCSS) previously showed an increased risk of all-cause mortality after stroke among childhood cancer survivors diagnosed between 1970 and 1986. In the current study, the investigators analyzed childhood cancer survivors diagnosed between 1970 and 1999 and compared their outcomes to those of the childhood cancer survivors’ siblings and a population-based cohort of racially diverse adults from the CARDIA (Coronary Artery Risk Development in Young Adults) study. Among the 25,658 childhood cancer survivors included in the current analysis, the median age of cancer diagnosis was 7 years (interquartile range [IQR]: 3-13), and the most common cancer diagnoses were leukemia (40.1%), lymphoma (17.6%) and other solid tumors (20.1%). About half of this population as treated with anthracyclines (53.1%) or radiation of a field involving the heart (49.8%), and 28.3% received brain radiation. These survivors were compared to 5,051 siblings and 5,114 CARDIA participants. Cancer survivors experienced a higher rate of major cardiovascular events (6.4%) compared to siblings (1.8%). CARDIA participants had a similar prevalence of major cardiovascular events (6.7%) to cancer survivors, with a lower prevalence of heart failure (cancer survivors 3.0% vs. CARDIA 1.8%), higher prevalence of CAD (cancer survivors 1.8% vs. CARDIA 3.3%) and similar stroke prevalence (cancer survivors 2.1% vs. CARDIA 2.2%). The median age of the first cardiovascular event among cancer survivors was 31 years (IQR: 22-39), among siblings was 35 years (IQR: 24-47) and among CARDIA participants was 57 years (IQR: 25-66). All-cause mortality through 10 years after a major cardiovascular event was significantly higher among cancer survivors than siblings for heart failure (30% [95% confidence interval (CI): 26% to 33%] vs. 14% [95% CI: 0% to 25%]), CAD (36% [95% CI: 31% to 40%] vs. 14% [95% CI: 2% to 25%]) and stroke (29% [95% CI: 24% to 33%] vs. 4% [95% CI: 0% to 11%]; p<0.001 for all). CAD-specific mortality risk was increased among cancer survivors compared to siblings (hazard ratio [HR]: 3.70; 95% CI: 1.05-13.02). Although the CARDIA participants had a median age 26 years higher than that of cancer survivors at their first major cardiovascular event, the mortality risks were similar between these two groups, except that post-CAD all-cause mortality was significantly higher among childhood cancer survivors (HR: 1.85; 95% CI:1.16-2.95). “Optimized clinical care in the setting of a cardiovascular event, greater inclusion of survivors in clinical trials, enhanced risk factor modification, and improved access to care that directly considers late effects of cancer therapy, are potential pathways to address disparities in mortality among survivors compared with noncancer cohorts who experience a major cardiovascular event,” the authors concluded. In an accompanying editorial, Lavanya Kondapalli, MD, and Linda Overholser, MD, MPH, both of the University of Colorado, Aurora, and Carrie Lenneman, MD, MSc, of the University of Alabama, Birmingham, commended Bottinor and colleagues for their work but also highlighted the shortcomings in current cardiac survival research. The editorialists pointed out that in a 2019 questionnaire for CCSS cancer survivors, the participants’ answers depend largely on their own understanding of their cardiac health. They added that childhood cancer survivors require more than routine management of traditional cardiovascular risk factors, especially because of the earlier age at which this population experiences a major cardiovascular event. “The data are clear that the burden of CV [cardiovascular] risk and disease is high in childhood cancer survivors—the onus is now on us to do something about it,” the expert commenters concluded. Sources: Bottinor W, Im C, Doody DR, et al. Mortality After Major Cardiovascular Events in Survivors of Childhood Cancer. J Am Coll Cardiol 2024;83:827–838. Kondapalli L, Overholser L, Lenneman C. Cardiac Care of Childhood Cancer Survivors: Time to Act Instead of React. J Am Coll Cardiol 2024;83:839–842. Image Credit: Julia – stock.adobe.com