Recent advancements in comprehensive genetic analyses for human hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) typically develops in the liver with chronic hepatitis and cirrhosis, and activation of oncogenes and inactivation of tumor suppressor genes occurs during carcinogenesis via genetic and epigenetic mechanisms. Recent advancements in the development of analyses for examining the cancer genome have revealed information regarding genetic alterations in HCC tissues. According to previous studies, the incidence of recurrent genetic alterations in individual genes was thought to be relatively rare and limited to a subset of a few cancer-specific genes such as tumor suppressor p53, RB genes and oncogenes such as CTNNB1. However, recent whole-genome analyses and exome sequencing of tumor DNA have revealed numerous novel alterations of cancer-related genes and pathways critical for HCC development. In addition, various risk factors for HCC, such as the presence or absence of hepatitis B and C virus, may affect the mutation profile of the corresponding cancer genome. On the other hand, genome-wide association studies have also identified important single-nucleotide polymorphisms involved in HCC development, which may allow detection of a group at high risk of HCC emergence. Such analyses will clarify how this malignancy can be treated, diagnosed and prevented more effectively.