DNA methylation aging clocks and pancreatic cancer risk: Pooled analysis of three prospective nested case-control studies

Abstract

Structured AbstractBackgroundPancreatic cancer is projected to become the second leading cause of cancer-related death by 2030 in the United States. DNA methylation (DNAm) age may reflect age-related variations in the biological changes and abnormalities related to cancer development.MethodWe conducted a pooled analysis using prediagnostic blood samples of pancreatic cancer cases and matched controls selected from the Nurses’ Health Study (NHS), the Physician’s Health Study (PHS), and the Health Professionals Follow-up Study (HPFS). We used three DNAm aging clocks (Hannum, Horvath, and PhenoAge) to estimate subjects’ DNAm age, epigenetic age acceleration (AA) and intrinsic epigenetic age acceleration (IEAA) metrics. We performed conditional logistic regression and multivariable Cox proportional hazard regression to examine associations between six AA and IEAA metrics and risk of pancreatic cancer and survival, respectively.ResultsA total of 393 incidence pancreatic cancer cases and 431 matched controls from the NHS, PHS, and HPFS cohorts were included in this analysis. The medians of all three epigenetic AA and three IEAA metrics were consistently above zero (indicating accelerated age) among cases, while they were below zero (indicating decelerated age) among the matched controls. Comparing participants in the highest quartile of age acceleration metrics, the pancreatic cancer risks were significantly increased by 67% to 83% for Hannum and PhenoAge AA or IEAA metrics with minimal of 7- to 9-years accelerated ages. Except for Hovarth AA and IEAA metrics, there were significant dose-response trends, such that higher age accelerations were associated with higher pancreatic cancer risk, but the relationships were nonlinear. Stratified analyses showed heterogeneous associations, varying by participants’ characteristics and by epigenetic AA or IEAA metrics. As time to diagnosis increased, the ORs of pancreatic cancer for the Hannum AA and Horvath AA or IEAA metrics trended upwards, while the ORs for the PhenoAge AA or IEAA and Hannum IEAA metrics trended downward. Overall, we observed no significant association between pancreatic cancer survival and any of the prediagnostic epigenetic AA or IEAA metrics.ConclusionOur results indicate DNAm age acceleration is associated with an increased risk of pancreatic cancer in a nonlinear, dose-response manner. Epigenetic IEAA metrics may be a useful addition to current methods for pancreatic cancer risk prediction.