775 Background: Delayed diagnosis and rapid progression are major drivers of poor survival outcomes for Pancreatic Ductal Adenocarcinoma (PDAC). In previous studies, molecular profiling in tumor tissue has identified Cholesterogenic, Classical, or Exocrine-Like pathological subtypes associated with improved prognosis. Herein, in a clinical trial called Project Survival, we molecularly and clinically characterized a prospective PDAC biomarker cohort. This multicenter (n=6) clinical trial (NCT 02781012) of PDAC combined with high-fidelity longitudinal phenotypic characterization and multi-omic profiling was utilized to identify biomarkers with diagnostic and therapeutic utility. The study included assessment of plasma, serum, buffy coat, urine, saliva, and tumor tissue samples and followed 269 PDAC subjects for up to 7 years (Median survival was 700 days, with IQR of 822 days). Methods: We assessed plasma samples to identify circulating biomarkers using proteomics, metabolomics, and lipidomics profiling. Multi-omic comparison of patients with Overall Survival (OS) above the 75th percentile (improved survival) against those with OS below the 25th percentile (poor survival) was performed. Results: We identified distinct panels of proteins, metabolites, and lipids that were associated with patient survival outcomes. Protein biomarkers that were increased in improved survival outcomes were associated with cholesterol metabolism (7/14, p-value = 0.00085) and glycolysis/gluconeogenesis (5/12, p-value = 0.00089), however, protein markers associated with immune surveillance and inflammation were associated with poorer survival. For metabolite biomarkers, 19 metabolites were increased in poorer survivors of which 13/19 were carnitine metabolites, and 42 metabolites were increased in patients with improved survival. Interestingly, only two lipid molecular species of the diacylglyceride family were increased in patients with poorer survival. Conclusions: Project Survival, a prospective biomarker-driven clinical trial identified distinct metabolic and molecular subtypes of patients which characterize survival outcome in PDAC. These subtypes go beyond tumor genomic characterization and align with distinct cholesterogenic and glucogenic phenotypes associated with survival outcomes, which can potentially be leveraged for therapeutic intervention strategies.
Read full abstract