CV Risk Disparities by Race/Ethnicity Persist in Childhood Cancer Survivors

Among childhood cancer survivors followed over three decades, those who identify as non-Hispanic Black and Hispanic bear an increased burden of cardiovascular risk factors compared with non-Hispanic white patients, similar to what is observed in the general population, new data confirm.

Prior research has shown an increased likelihood of CVD events, including silent cardiac conditions, for those who have survived childhood cancers. But as more and more of these patients are surviving to adulthood, little is known about the long-term effects of cardiotoxic treatments such as anthracycline and chest-directed radiotherapy, much less whether race and ethnicity plays into patient outcomes.

“Although similar to disparities in the general population, the potential for these cardiovascular risk factors to worsen therapy-related CVD motivates further actions to provide equitable survivorship-focused care for all survivors,” write David H. Noyd, MD, MPH (The University of Oklahoma Health Sciences Center, Oklahoma City, OK), and colleagues.

Commenting on the findings for TCTMD, Jörg Herrmann, MD (Mayo Clinic, Rochester, MN), said in an email that “these data help us to recognize that there are groups of cancer survivors that are particularly vulnerable and need even greater attention. In addition to the implications on the individual provider and patient level, these data also call for addressing and correcting factors contributing to these disparities on a larger population-based scale.”

Differences in Hypertension, Diabetes, and Obesity

For the study, which was published online this week in JACC: CardioOncology, Noyd and colleagues included 16,457 participants from the Childhood Cancer Survivor Study (CCSS) who were at least 5-year survivors of a multitude of malignancies diagnosed between 1970 and 1999.

Non-Hispanic Black and Hispanic survivors were generally more likely to be exposed to anthracycline compared with non-Hispanic whites. However, non-Hispanic white survivors were more likely to have received chest-directed radiotherapy—and at higher doses—compared with the other cohorts.

Those who identified as non-Hispanic Black (n = 1,092) and Hispanic (n = 1,405), compared with non-Hispanic white participants (n = 13,960), reported higher cumulative incidences of diabetes (8.4%, 9.7%, and 5.1%), obesity (47.2%, 48.9%, and 30.2%), and multiple cardiovascular risk factors (17.7%, 16.6%, and 12.3%) by age 40. Additionally, non-Hispanic Black survivors, but not Hispanics, had a greater cumulative incidence of hypertension as well, compared with non-Hispanic whites (19.5%, 13.6%, and 14.3%; P < 0.001 for all).

After adjusting for sociodemographic and treatment factors, the incidence rate ratios (IRRs) went up for non-Hispanic Black compared with non-Hispanic white survivors for hypertension (IRR 1.4; 95% CI 1.1-1.8), obesity (IRR 1.7; 95% CI 1.4-2.1), and multiple cardiovascular risk factors (IRR 1.6; 95% CI 1.2-2.1). Similar patterns were seen in Hispanic survivors for diabetes (IRR 1.8; 95% CI 1.2-2.6) and obesity (IRR 1.4; 95% CI 1.2-1.7).

The differences observed for rates of all cardiovascular risk factors between the various racial/ethnic groups were similar to the gaps by race and ethnicity seen in healthy sibling survey data from the CCSS, as well as in National Health and Nutrition Examination Survey cohorts.

The authors write that their data should motivate “additional investigation into potential systemic causes of these differences and possibly differences in genetic predisposition to late cardiac outcomes, such as cardiomyopathy.”

Additionally, they say, US childhood cancer survivors in general suffer from a more-intense disease burden with each additional risk factor that’s present, “with cumulative incidence estimates ranging from 5% (diabetes) to 50% (obesity) by age 40, thus further stressing the opportunity to promote equity in cardiovascular health on a population level.”