Single nucleotide polymorphisms in the mitochondrial displacement loop and age-at-onset of epithelial ovarian cancer.

Objective: The accumulation of the single nucleotide polymorphisms (SNPs) in the mitochondrial displacement loop (D-loop) has been reported in many types of cancers. And the association with the risk and prognosis of cancers also has been described extensively. In the present study, we investigated the association between the age-at onset and SNPs in the D-loop of mitochondria DNA (mtDNA) using a population-based series of primary epithelial ovarian cancer (EOC) patients. Methods: The D-loop region of mtDNA samples from blood were obtained from 89 patients with primary EOC, who underwent surgery. The age-at-onset curves were calculated by Kaplan-Meier method and compared by the log-rank test. Results: The SNP sites of nucleotide 248, 524 and 16,304 alleles were identified for their association with age-at-onset by the log-rank test. The age-at-onset of patients with the minor allele 248G was lower than that of patients with 248A. The same was seen for the rare allele 16,304T genotype when compared with matched allele 16,304C at the 16,304 site. But the age-at-onset of patients with the minor allele 524C was higher than that of patients with frequent 524 deletions. Conclusion: Genetic polymorphisms in the D-loop are the predictive markers for age-at-onset in EOC patients. Accordingly, the analysis of genetic polymorphisms may help identify EOC patient subgroups at high risk of early onset.