Comparison of ctDNA markers in matched urine and plasma from patients with liver cancer

Abstract Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer worldwide and a leading cause of global cancer mortality. Lack of efficient early detection and limited therapeutic options are two key contributing factors for the dismal prognosis of this disease. We have previously shown that urine contains fragmented, circulation-derived cell-free DNA that can be used for detection of circulating tumor DNA (ctDNA) if a tumor is present, suggesting urine as an alternative body fluid to plasma for cancer liquid biopsy. This study compared the detectability of five known HCC-associated DNA modifications, including genetic mutations (TERT -124 G>A, TP53 249 G>T and CTNNB1 hotspot at codon 32-45) and epigenetic methylation (mGSTP1, mRASSF1A), in matched urine and plasma from patients with liver cancer. In order to increase the sensitivity of detecting DNA modifications from the short, fragmented DNA templates, specialized short amplicon PCR assays were developed. To compare the detectability of HCC ctDNA markers in urine and plasma, 26 pairs of urine and plasma samples from HCC patients were identified and tested for five HCC ctDNA markers. In this cohort, 17 of 26 (65%) HCC samples had serum AFP above 20 ng/mL and were considered AFP-positive HCC. By using our HCC DNA biomarker panel composed of 5 assays, 22/26 (84.6%) urine and 23/26 (88.5%) plasma samples were found to have at least one DNA marker detected. In the combination of our HCC DNA biomarker panel with serum-AFP, the sensitivity of HCC detection in a liquid biopsy of urine and plasma as compared to serum-AFP alone (the current most used screening marker) increased from 65% to 92.3% for both urine plus AFP and plasma plus AFP. Further studies to include non-HCC samples (such as cirrhosis) to determine the specificity of the HCC DNA biomarker panel for liquid biopsy are in progress. In conclusion, our research provides the promising potential for HCC liquid biopsy screening in at-risk populations and precision medicine by using plasma, urine, or both as body fluids. Citation Format: Tai-Jung Lee, Surbhi Jain, Jamin D. Steffen, Adam M. Zhang, Chi-Tan Hu, James P. Hamilton, Ying-Hsiu Su. Comparison of ctDNA markers in matched urine and plasma from patients with liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3661.