Survivors of Childhood Cancer More Likely to Be Undertreated for CVD Risk Factors

Adult survivors of childhood cancer have an increased risk of cardiovascular disease (CVD), but are undertreated for CVD risk factors, according to a study published in Journal of the American Heart Association.

Exposure to chemotherapy and/or radiation increases the risk of CVD and death for survivors of childhood cancer compared with the general population. The authors of this new study sought to determine not only the prevalence of underdiagnosis and undertreatment of CVD among these individuals, but also predictors associated with modifiable CVD risk factors, such as hypertension, dyslipidemia, and diabetes.

“These modifiable risk factors appear to be synergistic with the cardiotoxic effects of cancer treatments and potentiate survivors’ risk of ischemic heart disease and heart failure more than they do in the general population,” they wrote. “Survivors also tend to develop CVD risk factors at younger ages compared with siblings or the general population.”

The authors utilized the Childhood Cancer Survivor Study (CCSS), which includes 25,665 individuals with cancer diagnosed before the age of 21 years. The individuals in the study had been diagnosed in 31 institutions in the United States and Canada between 1970 and 1999, and they survived at least 5 years after their diagnosis. They recruited participants of the study in the United States who were free of known ischemic heart disease or heart failure.

Ultimately, 571 participants were included in the analysis. More than half (56.9%) were women and 85.1% were non-Hispanic White. The median age was 37.7 years. These individuals were compared with 9544 individuals from the 2015 to 2016 National Health and Nutrition Examination Survey (NHANES).

The CCSS group was more likely to have CVD risk factors:

• 18.0% had hypertension vs 11.0% in the NHANES group
• 14.0% had dyslipidemia vs 4.9% in NHANES
• 6.5% had diabetes vs 3.2% in NHANES

Although the groups had similar rates of underdiagnosed CVD risk factors (27.1% among CCSS and 26.1% among NHANES), the cancer survivors were 80% more likely to be undertreated.

“Serious heart disease is uncommon in young adults in the general population, which includes childhood cancer survivors; therefore, greater awareness of the significantly higher cardiovascular disease risk when there is a history of cancer is important,” lead study author Eric J. Chow, MD, MPH, an associate professor in clinical research and public health sciences at the Fred Hutchinson Cancer Center in Seattle, said in a statement. “Raising awareness among primary care professionals as well as improving survivors’ ability to self-manage their health may mitigate the increased risks. There are specialized heart disease risk calculators designed for cancer survivors, and those may be more accurate in predicting future cardiovascular disease risk than risk calculators designed for the general population.”

The authors determined that male sex, increased body mass index, and the presence of 2 or more adverse lifestyle factors were all associated with underdiagnosis and undertreatment of CVD risk factors in the cancer survivor group. However, survivors who reported greater health-related self-efficacy or who scored higher on internal locus of control beliefs, with a lower score related to a person’s belief that they can control events in their lives, were less likely to be undertreated.

One of the limitations the authors noted was that undertreatment status was based on a 1-time measurement, while diagnosis of these favors typically requires repeat testing. As a result, there may have been a misclassification of undertreatment.

“In conclusion, CVD risk factor underdiagnosis and undertreatment among childhood cancer survivors at increased risk of heart disease was common,” the authors wrote. “Greater awareness among survivors, primary care providers, and cardiologists, combined with increased self‐efficacy among survivors and more aggressive control of these risk factors by providers, may mitigate this risk.”

Reference

Chow EJ, Chen Y, Armstrong GT, et al. Underdiagnosis and undertreatment of modifiable cardiovascular risk factors among survivors of childhood cancer. J Am Heart Assoc. Published online June 8, 2022. doi:10.1161/JAHA.121.024735