Data from: Peripheral blood mitochondrial DNA copy number is associated with prostate cancer risk and tumor burden

Alterations of mitochondrial DNA (mtDNA) have been associated with the
risk of a number of human cancers; however, the relationship between mtDNA
copy number in peripheral blood leukocytes (PBLs) and the risk of prostate
cancer (PCa) has not been investigated. In a case-control study of 196 PCa
patients and 196 age-paired healthy controls in a Chinese Han population,
the association between mtDNA copy number in PBLs and PCa risk was
evaluated. The relative mtDNA copy number was measured using quantitative
real-time PCR; samples from three cases and two controls could not be
assayed, leaving 193 cases and 194 controls for analysis. PCa patients had
significantly higher mtDNA copy numbers than controls (medians 0.91 and
0.82, respectively; P<0.001). Dichotomized at the median value of
mtDNA copy number in the controls, high mtDNA copy number was
significantly associated with an increased risk of PCa (adjusted odds
ratio = 1.85, 95% confidence interval: 1.21–2.83). A significant
dose-response relationship was observed between mtDNA copy number and risk
of PCa in quartile analysis (Ptrend = 0.011). Clinicopathological analysis
showed that high mtDNA copy numbers in PCa patients were significantly
associated with high Gleason score and advanced tumor stage, but not serum
prostate-specific antigen level (P = 0.002, 0.012 and 0.544,
respectively). These findings of the present study indicate that increased
mtDNA copy number in PBLs is significantly associated with an increased
risk of PCa and may be a reflection of tumor burden.