Bovine leukemia virus relation to human breast cancer: Meta-analysis

Bovine leukemia virus (BLV) is a virus that infects cattle around the world and is very similar to the human T-cell leukemia virus (HTLV), which causes adult T-cell leukemia/lymphoma (ATL). Recently, presence of BLV DNA and protein was demonstrated in commercial bovine products and in humans. BLV DNA is generally found at higher rates in humans who have or will develop breast cancer, according to research done with subjects from several countries. These findings have led to a hypothesis that BLV transmission plays a role in breast cancer oncogenesis in humans. Here we summarize the current knowledge in the field. •DNA of BLV is found at higher rates in humans who have or will develop breast cancer.•Global analysis links the frequency of breast cancer cases to consumption of milk and beef in the countries studied.•These findings have led to a hypothesis that BLV transmission plays a role in breast cancer oncogenesis.•There are contradicting results in majority of cases can be explained by different experimental methods used.