Abstract 468: Associations of circulating miRNAs with pancreatic cancer risk differ by years between blood collection & and cancer diagnosis
Authors: Cai Hui , Setiawan Veronica Wendy , Guo Xingyi , Wu Jie , Stolzenberg-Solomon Rachael Z , Zhu Claire , Gao Yu-Tang , Berlin Jordan , Ye Fei , Cai Qiuyin , Zheng Wei , Shu Xiao-ou 
Published: March 2024

Abstract
Pancreatic adenocarcinoma (PDAC) is one of the most fatal cancers and currently used biomarkers for PDAC diagnosis are not adequate for early detection. Therefore, new biomarkers for PDAC early detection are urgently needed. We conducted a large-scale study to prospectively evaluate the association of circulating miRNAs with PDAC risk. Specially, we aimed to examine whether the associations of miRNAs expression levels and changes of those levels from blood collection to cancer diagnosis (BCCD) with PDAC risk. We used pre-diagnostic plasma samples of 1307 PDAC cases from 5 cohort studies (290 from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, 395 from the Shanghai Women’s and Men’s Health Studies, 154 from the Southern Community Cohort Study, and 468 from the Multiethnic Cohort). Cancer free controls (n=1307) were selected and individually matched to index cases in each cohort. All miRNAs were measured by the NanoString nCounter Analysis System using the Human v3 miRNA Expression panel (798 miRNAs total). Data were pooled and quantile normalized prior to analysis. Associations of circulating miRNAs with PDAC risk were assessed by odds ratio per decile change in miRNA levels using conditional logistic regression. Fold-change of miRNA for cases versus controls by BCCD was analyzed via linear regression. Median time of BCCD was 7.13 years (range: 0.03-19.61 years). We first conducted the association analysis stratified by BCCD: &lt; 5 years, 5-10 years, and &gt;10 years. We found 20 miRNAs were significantly associated with PDAC risk in the &lt;5 years after FDR correction. In the analysis of regressing fold-change of these 20 miRNAs on BCCD, we found the fold change of miR-155-5p was inversely associated with BCCD (β=-0.04, P&lt;0.01), i.e., the case-control difference was larger when blood was drawn closer to PDAC diagnosis, suggesting its potential utility as disease biomarkers for early detection. Conversely, the fold-change of miR-93-5p (β=0.04, P=0.01), miR-223-3p (β=0.03, P=0.02), let-7i-5p (β=0.03, P&lt;0.01), and miR-191-5p (β=0.05, P&lt;0.01) were positively associated with BCCD, i.e., the case-control difference increased with an increasing the time interval of BCCD, indicating they are more likely biomarkers for PDAC risk. Ingenuity pathway analyses of these five significant miRNAs revealed that they were significantly enriched in ribonucleotide reductase signaling pathways at p&lt;0.05. Notably, the silencing of ribonucleotide reductase M2 subunit suppresses tumorigenesis in pancreatic cancer by deactivating the PI3K/AKT/mTOR pathway, further supporting our findings.
Findings of this large-scale multiethnic study suggest that changes in circulating levels of let-7i-5p, miR-155-5p, miR-93-5p, miR-191-5p, and miR-223-3p may help identify individuals at an elevated risk of developing PDAC, allowing for screening tests and close surveillance.
Citation Format: Hui Cai, Veronica Wendy Setiawan, Xingyi Guo, Jie Wu, Rachael Z Stolzenberg-Solomon, Claire Zhu, Yu-Tang Gao, Jordan Berlin, Fei Ye, Qiuyin Cai, Wei Zheng, Xiao-ou Shu. Associations of circulating miRNAs with pancreatic cancer risk differ by years between blood collection & and cancer diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 468.