Mitochondrial DNA haplogroup M is associated with late onset of hepatocellular carcinoma.

The accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) has been associated with various types of cancer. The association of SNPs with cancer risk and disease outcome has been exhaustively studied. In this study, we investigated the association of age-at-onset and SNPs in the mitochondrial D-loop using a population-based series of hepatocellular carcinoma (HCC) patients. Haplogroup M (489C) and allele 235G were identified for their association with the late onset of HCC by the log-rank test. In an overall multivariate analysis, haplogroup M (489C) was identified as an independent predictive factor for the age-at-onset of HCC at borderline significant levels [relative risk, 1.736; 95% confidence interval (CI), 0.967-3.115; p=0.065]. Genetic polymorphisms in the D-loop are predictive markers for age-at-onset in HCC patients. Accordingly, the analysis of genetic polymorphisms in the mitochondrial D-loop may help to identify HCC patient subgroups at high risk of early onset of the disease.