Background: Childhood cancer survivors experience significantly higher rates of hypertension which potentiates cardiovascular disease, but the contribution and relationship of genetic and treatment factors to hypertension risk are unknown.
Objectives: To determine the contribution of a blood pressure polygenic risk score (PRS) from the general population and its interplay with cancer therapies to hypertension in childhood cancer survivors.
Methods: Using 895 established blood pressure loci from the general population, we calculated a PRS for 3572 childhood cancer survivors of European ancestry from Childhood Cancer Survivor Study (CCSS) original cohort, 1889 from CCSS expansion cohort, and 2534 from the St. Jude Lifetime Cohort (SJLIFE). Hypertension was assessed using National Cancer Institute criteria based on self-report of a physician diagnosis in CCSS and by blood pressure measurement in SJLIFE.
Results: In the combined sample of 7995 survivors, those in the top decile of the PRS had an odds ratio (OR) of 2.66 (95% CI=2.03-3.48) for hypertension compared to survivors in the bottom decile. The PRS-hypertension association was modified by being overweight/obese (per SD interaction OR=1.13; 95% CI=1.01-1.27) and exposure to hypothalamic-pituitary axis radiation (per SD interaction OR=1.18; 95% CI=1.05-1.33). Attributable fractions for hypertension to the PRS and cancer therapies were 21.0% and 15.7%, respectively, they jointly accounted for 40.2% of hypertension among survivors.
Conclusions: A blood pressure PRS from the general population is significantly associated with hypertension among childhood cancer survivors and contributes to approximately one quarter of hypertension risk among survivors. These findings highlight the importance of screening for hypertension in all childhood cancer survivors, and identify higher risk subgroups.
Keywords: Hypertension; cancer therapies; childhood cancer survivors; polygenic risk score.