Abstract Importance: Pancreatic cancer presents as advanced disease in >80% of patients; yet, appropriate ages to consider prevention and early detection strategies are poorly defined. Objective: To investigate age-specific associations and attributable risks of pancreatic cancer for established modifiable and non-modifiable risk factors. Design, Setting, and Participants: We included 167,483 participants from 2 prospective U.S. cohort studies with 1190 incident cases of pancreatic cancer identified during >30 years of follow-up; 5107 pancreatic cancer cases and 8845 control participants of European ancestry from a completed multicenter genome-wide association study (GWAS); and 248,893 pancreatic cancer cases documented in the U.S. Surveillance, Epidemiology, and End Results (SEER) Program. Exposures: Across different age categories, we investigated cigarette smoking, obesity, diabetes, height, and non-O blood group in the prospective cohorts; weighted polygenic risk score of 22 previously identified single nucleotide polymorphisms in the GWAS; and male sex and Black race in the SEER program. Main outcomes and measures: Risk of developing pancreatic cancer by age evaluated by Cox, logistic, or Poisson regression, as determined by the study design. Results: In the prospective cohorts, all 5 risk factors were more strongly associated with pancreatic cancer risk among younger participants, with associations greatly attenuated among those over 70 years. The HRs comparing participants with 3-5 risk factors to those with no risk factors were 9.24 (95% CI, 4.11-20.77) among those aged ≤60 years, 3.00 (95% CI, 1.85-4.86) among those aged 61-70 years, and 1.46 (95% CI, 1.10-1.94) among those over 70 years (Pheterogeneity = 3×10-5). These factors together were related to 65.6%, 49.7%, and 17.2% of incident pancreatic cancers in these age groups, respectively. In the GWAS, the polygenic risk score was most strongly associated with pancreatic cancer risk among those aged ≤60 years, with lesser associations identified in older participants (Pheterogeneity = .01). In the SEER Program, male sex and Black race were also more strongly associated with pancreatic cancer risk among younger individuals (Pheterogeneity < 1×10-8). Conclusions and relevance: Inherited and lifestyle factors are more strongly associated with earlier-onset pancreatic cancer, emphasizing the importance of age at initiation for cancer prevention and control programs targeting this highly lethal malignancy. Citation Format: Chen Yuan, Jihye Kim, Qiao-Li Wang, Alice A. Lee, Ana Babic, PanScan/PanC4 I-III Consortium, Laufey T. Amundadottir, Alison P. Klein, Donghui Li, Marjorie L. McCullough, Gloria M. Petersen, Harvey A. Risch, Rachael Z. Stolzenberg-Solomon, Kimberly Perez, Kimmie Ng, Edward L. Giovannucci, Meir J. Stampfer, Peter Kraft, Brian M. Wolpin. The age-dependent association of risk factors with pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5891.