Cardiovascular Risk Factor Disparities in Adult Survivors of Childhood Cancer Compared With the General Population

Abstract

Background: It is unknown whether a history of childhood cancer modifies the established disparities in cardiovascular risk factors (CVRFs) observed in the general population.

Objectives: We sought to determine if disparities in CVRFs by race/ethnicity are similar among childhood cancer survivors compared with the general population.

Methods: The Childhood Cancer Survivor Study (CCSS) is a retrospective cohort with a longitudinal follow-up of 24,084 5-year survivors diagnosed between 1970 and 1999. Multivariable piecewise exponential regression estimated incidence rate ratios (IRRs) for hypertension, hyperlipidemia, diabetes, obesity, and ≥2 CVRFs by race/ethnicity. The CCSS sibling cohort and the National Health and Nutrition Examination Survey cohort were used to compare the sociodemographic-adjusted IRRs for same-race/same-ethnicity disparities.

Results: Non-Hispanic Black (NHB) (n = 1,092) and Hispanic (n = 1,405) survivors compared with non-Hispanic White (NHW) (n = 13,960) survivors reported a higher cumulative incidence of diabetes (8.4%, 9.7%, and 5.1%, respectively); obesity (47.2%, 48.9%, and 30.2%, respectively); multiple CVRFs (17.7%, 16.6%, and 12.3%, respectively); and, for NHB survivors, hypertension (19.5%, 13.6%, and 14.3%, respectively) by 40 years of age (P < 0.001). Controlling for sociodemographic and treatment factors compared with NHW survivors, IRRs for NHB were increased for hypertension (IRR: 1.4; 95% CI: 1.1-1.8), obesity (IRR: 1.7; 95% CI: 1.4-2.1), and multiple CVRFs (IRR: 1.6; 95% CI: 1.2-2.1). IRRs for Hispanic survivors were increased for diabetes (IRR: 1.8; 95% CI: 1.2-2.6) and obesity (IRR: 1.4; 95% CI: 1.2-1.7). The pattern of IRRs for CVRF differences was similar among CCSS sibling and National Health and Nutrition Examination Survey cohorts.

Conclusions: The higher burden of CVRFs among NHB and Hispanic survivors compared with NHW survivors was similar to the general population. The promotion of cardiovascular health equity is critical in this high-risk population.

Keywords: cardiovascular risk factors; childhood cancer survivors; health equity.

Graphical abstract

Central Illustration

Cardiovascular Risk Factor Disparities Among Survivors Compared With the General Population The burden of diabetes, hypertension, hyperlipidemia, obesity, and multiple cardiovascular risk factors (CVRFs) contribute to the incidence of cardiovascular disease (CVD) across the life span for both survivors and the general population. For survivors, anthracyclines and chest radiation are directly cardiotoxic, whereas CVRFs are known to potentiate risk for CVD beyond the expected additive risk, thus emphasizing the increased importance to mitigate CVRFs among survivors and motivating further actions to provide equitable survivorship-focused care for all survivors. This analysis observed similar disparities by race/ethnicity compared with the general population, with non-Hispanic Black and Hispanic survivors reporting a higher cumulative incidence of diabetes, obesity, and multiple CVRFs. CCSS = Childhood Cancer Survivor Study; CV = cardiovascular; CVD = cardiovascular disease; NHANES = National Health and Nutrition Examination Survey.

Figure 1

Consort Diagram for the CCSS The Childhood Cancer Survivor Study is a retrospective cohort that includes 25,656 childhood cancer survivors who were diagnosed at 1 of 31 North American centers between 1970 and 1999 who had survived at least 5 years after a diagnosis of leukemia, central nervous system malignancy, Hodgkin lymphoma, non-Hodgkin lymphoma, Wilms tumor, neuroblastoma, soft tissue sarcoma, or a bone tumor. Survivors with subsequent malignancies or late recurrence occurring before 20 years old, younger than 20 years of age at baseline questionnaire, and with missing race/ethnicity data were excluded, allowing 16,457 survivors for analysis.

Figure 2

Cumulative Incidence (%) of CVRFs by Race/Ethnicity Age is on the x-axis, and cumulative incidence is on the y-axis (95% CIs shaded). (A) Hypertension, (B) hyperlipidemia, (C) diabetes, (D) obesity, and (E) multiple CVRFs. Non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic cumulative incidence by age are represented in black, blue, and red, respectively. Each cardiovascular risk factor (CVRF) was determined based on a self-report of both being diagnosed by a physician and on medication based on Common Terminology Criteria for Adverse Events v.4.03 criteria. The cumulative incidence for each CVRF started at cohort entry (5 years after diagnosis) and ended at the first CVRF event of interest for each individual CVRF analysis or at a competing risk event, which included recurrence, subsequent malignant neoplasm, and death, or censored at the completion of the last questionnaire.

Figure 3

CVRFs by Race/Ethnicity for Each Cohort A multivariable piecewise exponential model was used to compare incidence rate ratios to assess the magnitude of the same-race/same-ethnicity survivor-sibling differences between racial and ethnic groups, with modifications by generalized estimating equations to account for possible within-family correlation between survivors and siblings from the same families. Multivariable logistic regression was used in calculating prevalence odds ratios in National Health and Nutrition Examination Survey (NHANES) data. For all analyses, age, sex, household income, educational attainment, marital status, employment, and insurance were included in the multivariable adjustment. Point estimates and CIs for non-Hispanic Black (NHB) and Hispanic participants are in blue and red, respectively. CCSS = Childhood Cancer Survivor Study; CVRF = cardiovascular risk factor.