Inherited Chromosomally Integrated Human Herpesvirus 6 and Breast Cancer

Background: Inherited chromosomally integrated human herpesvirus 6 (iciHHV-6) is a condition observed in approximately 1% of the population. Whether such a genetic alteration predisposes to cancer development in currently unknown. Two studies were conducted to determine whether iciHHV-6 is associated with cancer development. Methods: First, a screen of 19,597 people from the province of Quebec (Canada) was conducted. A replication test, using data from a population-based case-control study of 1,090 women with incident breast cancer and 1,053 controls from British Columbia and Ontario (Canada) was conducted. DNA samples were analyzed by qPCR and droplet digital PCR to identify iciHHV-6(+) carriers. Results: In the initial study, a potential association between iciHHV-6 positivity and breast cancer was identified [OR = 2.66; 95% confidence interval (CI), 0.95-7.44]. In the replication dataset, no association was found between iciHHV-6 positivity in women and breast cancer (OR = 0.87; 95% CI, 0.35-2.15). Conclusions: We found no statistically significant associations between inherited chromosomally integrated HHV-6 and breast cancer in women. Impact: These results do not provide evidence to suggest that iciHHV-6 is a risk factor for breast cancer. (C)2016 AACR.