Source Laboratory for Digestive Diseases, RIKEN Center for Genomic Medicine, Hiroshima, Japan; Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.

Over the past several years, the success of genome-wide association studies (GWAS) and pharmacogenomics have gradually begun to enable personalized medicine in some fields. In the field of liver diseases, host genetic factors are now very useful in clinical practice for predicting treatment outcome and adverse reactions for pegylated interferon plus ribavirin combination therapy against chronic hepatitis C virus (HCV) infection.

Recently, three virus-related hepatocellular carcinoma (HCC) GWAS studies were reported from Asia. One study examined hepatitis B virus (HBV)-related HCC in China, where HBV is very prevalent, while the other two examined HCV-related HCC in Japan. We identified a common variant in the DEPDC5 locus associated with HCV-related HCC, and another group identified an association involving the MICA locus.

In this review, we compare the results of these GWAS studies and earlier candidate gene studies. Further research is needed to determine the role of these single nucleotide polymorphisms on HCC risk, but identification of these markers may make it possible to assess the magnitude of the risk of cancer based on each patient's genetic background. Consideration of the genetic background of the patients will likely play a role in personalized medicine for HCC, and understanding the mechanism underlying the association may suggest novel promising therapeutic targets in the future. © 2012 Japanese Cancer Association.