Pancreatic cancer (PC) is the third leading cause of cancer mortality in the United States. The vast majority of
PC are pancreatic ductal adenocarcinoma (PDAC). The etiology of PDAC is not fully understood. Basic research
supports a crucial role of certain proteins in PDAC development. Epidemiological studies also have identified
multiple candidate protein biomarkers for PDAC. However, findings with many of these protein biomarkers have
been inconsistent, potentially due to major methodological limitations, such as selection bias and uncontrolled
confounding. Besides understanding etiology, identifying causal protein biomarkers can potentially contribute to
improving risk prediction. For PC, substantial efforts have been made to identify high-risk populations for
improving PC screening. However, the performance of available PC risk prediction models remains
unsatisfactory. There are critical needs to 1) apply a novel study design with reduced limitations of conventional
biomarker studies for characterizing PC causally related protein biomarkers to improve the etiology
understanding; and 2) develop improved prediction models that may effectively facilitate PC risk assessment.
One strategy to potentially decrease limitations of unmeasured confounding is to use genetic instruments for
assessing the relationship between proteins and PDAC. While our previous studies have utilized proteins
measured in blood, it is also critical to study pancreatic ductal tissue, the most relevant tissue for PDAC
development, as levels of many proteins show tissue-specific effects. The proposed project will apply a series of
new studies to address these important knowledge gaps. Specifically, we will 1) conduct a study to identify
putative causal protein biomarkers for PDAC risk by applying novel methods (Aim 1); 2) functionally characterize
top protein biomarkers for their roles in PC biology (Aim 2); and 3) develop and validate prediction models for
PC risk, by incorporating newly identified candidate protein biomarkers and integrating results from multiple
statistical methods (Aim 3). Given the strong pilot data, unique resources, and our team's extensive expertise
and experience, we are uniquely positioned to conduct this project. Our study will generate important new
knowledge for PC etiology, and develop improved PC risk prediction models.