Comprehensive molecular characterization of liver cancer and inheritance of the phenotypic traits during tumor recurrence [methylation - classification]

Hepatocellular carcinoma (HCC) is a heterogeneous disease with a variety of etiological factors, and ranks as the second leading cause of cancer-related mortality worldwide due to multifocal recurrence. Comprehensive molecular evaluation of HCC by multiplatform analysis defined three major subtypes: (1) mitogenic and stem cell-like tumors with chromosomal instability; (2) CTNNB1-mutated tumors displaying DNA hypermethylation; and (3) metabolic syndrome-associated tumors, which included an immunogenic subgroup characterized by macrophage infiltration and favorable prognosis. Although genomic and epigenomic analysis explicitly discriminated HCC with intrahepatic metastasis (IM) from multicentric HCC (MC), the phenotypic similarity between the primary and recurrent tumors was not linked to the IM/MC diagnosis, but rather the integrated classification. Thus, identification of these HCC subtypes provides insights into patient stratification and opportunities for therapeutic development. For the Classification study, genomic DNA were obtained from 29 pairs of HCC and adjacent liver controls (L001 to L030, L022 was excluded because of low tumor purity).