Bovine leukemia virus linked to breast cancer in humans


Anew study from the University of California, Berkeley, shows that there may be a link between bovine leukemia virus (BLV) infections and human breast cancer.

In the study, researchers analyzed breast tissue from 239 woman, comparing these samples against woman with and without breast cancer looking for the presence of BLV. The study found that 59% of breast cancer samples had evidence of exposure to BLV, compared to 29% of the tissue samples from women who did not have breast cancer.

“The association between BLV infection and breast cancer was surprising to many previous reviewers of the study, but it’s important to note that our results do not prove that the virus causes cancer.”

Bovine leukemia virus infects cattle’s blood cells and mammary tissue. It is easily transmitted among cattle through infected blood and milk. However, only a small percent of cattle (<5%) get the disease. The study, that was published in this months PLOS ONE also finds that the statistical data shows that the odds of having breast cancer was 3.1x greater if BLV was present. That odds ratio is higher than other risk factors such as obesity and alcohol consumption.

“Buehring emphasized that this study does not identify how the virus infected the breast tissue samples in their study. The virus could have come through the consumption of unpasteurized milk or undercooked meat, or it could have been transmitted by other humans.”

Source Science Daily
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