Article Molecular Profile of Liver Tumors in the Setting of Fontan-Associated Liver Disease

Purpose: To analyze the genetic and molecular profile of liver nodules in the context of Fontan-associated liver disease (FALD) with the aim of identifying possible biomarkers for predictive outcome and personalized therapy. Methods: this retrospective monocentric study included 9 patients who developed FALD in the context of congestive cirrhosis:1 regenerative nodular hyperplasia, 2 hepatic adenomas (HA) and 4 hepatocellular carcinoma (HCC), 1 fibrolamellar carcinoma (FLC) and 1 intrahepatic cholangiocarcinoma (ICC). The lesions were analyzed by histology and immunohistochemistry (b-catenin, glypican 3, glutamine synthetase and SOX9). To study the molecular profile of neoplastic FALD, targeted NGS was performed on DNA and RNA from formalin-fixed paraffin embedded neoplastic liver tissue of 1 HA, 2 HCCs, 1 FLC and 1 ICC. Results: Molecular analysis showed 3 patients with copy number alteration involving FGFR3, and one patient with a hotspot mutation on CTNNB1 and NRAS genes. All 5 patients showed a tumor mutational burden ranging from low to intermediate. Variants of unknown significance in GNAS were present in 2 HCC and 1 ICC. The single FLC had a DNAJB1-PRKACA fusion. Conclusions: The molecular results seem to be consistent with a peculiar molecular profile of the malignant FALD which may be useful for new target therapies for HCC/ICC in FALD.