Mutational profile of hepatocellular carcinoma by liquid biopsy of Hispanics in central California.

Abstract

e16621 Background: Hepatocellular carcinoma (HCC) when localized to liver is typically diagnosed with Characteristic radiographic features while tumor tissue sampling is not warranted anymore. Recently, circulating tumor DNA (ctDNA) has been used to evaluate mutational profile in solid tumors in order to personalize treatments. However, it is not established well in HCC, specifically in Hispanic patients. This study aims to describe the mutational profile of Hispanic patients with ctDNA analysis as a single center experience. Methods: We enrolled 33 patients with diagnosis of HCC from 1/2016 to 12/2019. Diagnosis of HCC was based on Characteristic radiological features, defined by Liver Imaging Reporting and Data System (LI-RADS category 5). 18 patients self-identified as Hispanic while remaining were mainly Caucasians. FoundationOne Liquid genomic testing by Foundation Medicine was used for profiling of 77 most commonly mutated genes of sampled blood. Results: Baseline patient characteristics were similar between Hispanic and non-Hispanic population. Median age of diagnosis was 64 in this cohort with 23(70%) males and 10(30%) females. 30 patients had underlying cirrhosis with hepatitis C present in 19(58%) and heavy alcohol abuse in 15(45%) of cirrhotic. 32 patients had liver-only disease, while we had one patient with extrahepatic disease. 22 of these 33 patients had a single HCC lesion while 11 had multifocal HCC. 20 patients (60.6%) had at least 1 pathogenic mutation. 13 patients (39.4%) did not have any pathogenic mutations. The frequency of commonly mutated genes for our Hispanics versus non-Hispanics were following: CTNNB1(45.5% vs 44.4%), TERT (45.5% vs 55.6%), TP53(36.4% vs 55%), CNK2A (18.2% vs 0). Median of Allele frequency percentage was 0.81%. Mutations in TP53 was commonly detected at codon 249(R249S). Presence of these pathogenic mutations were associated with poor clinical features such as multifocal disease and higher AFP values > 59 as compared to 15 without mutations. Other mutations present at lower percentage include ERBB2, PIK3CA, DNMT3A, GNAS, KDR, RB1, PTEN and their frequency was similar in both Hispanic and non-Hispanic groups. Conclusions: Genomic profiling of ctDNA by liquid biopsy in our Hispanic patients with HCC appears similar to established mutational profile of HCC in Caucasian and Asian populations. These findings can be verified in heterogeneous populations in order to serve as a potential prognostic tool and help with personalized medicine.