Female-specific association among I, J and K mitochondrial genetic haplogroups and cancer: A longitudinal cohort study.

Recent studies highlighted the role of mitochondrial dysregulation in cancer, suggesting that the different mitochondrial haplogroups might play a role in tumorigenesis and risk of cancer development. Our aim is to investigate whether any mitochondrial haplogroups carried a significant higher risk of cancer development in a large prospective cohort of North American people. The haplogroup assignment was performed by a combination of sequencing and PCR-RFLP techniques. Our specific outcome of interest was the incidence of any cancer during follow-up period. Overall, 3222 participants were included in the analysis. Women having I, J, K haplogroup reported a significant higher incidence of cancer compared to people with other haplogroups (p < 0.0001), whilst in men non association was found. In the multivariate analysis, women having I, J, K mitochondrial haplogroup reported a 50% increased risk of cancer (HR = 1.50; 95%CI: 1.04-2.16; p = 0.03). This gender-linked association may be partly explained by the role of mitochondrial function in female-specific (e.g. BRCA-driven) oncogenesis, but further studies are needed to better understand this potential correlation. Our findings may have important implications for cancer epidemiology and prevention.