In a study available in the journal PLOS ONE, scientists discovered that in the 239 breast cancer tissues donated by women, nearly 60 percent of the breast cancer cells had bovine leukemia virus (BLV). However, in the breast tissue samples from women with no breast cancer, the BLV exposure was only 29 percent.

"This odds ratio is higher than any of the frequently publicized risk factors for breast cancer, such as obesity, alcohol consumption and use of post-menopausal hormones," said Gertrude Buehring, lead author of study from Berkeley's School of Public Health, in a press release. The existence of bovine leukemia virus in women's breast tissue may possibly increase the possibility of 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," Buehring explained.

Buehring added that if supplementary studies conducted found BLV to be the culprit at the back of breast cancer, it may possibly open up fresh treatment methods for the disease.

"If BLV were proven to be a cause of breast cancer, it could change the way we currently look at breast cancer control," said Buehring in a report by UPI. "It could shift the emphasis to prevention of breast cancer, rather than trying to cure or control it after it has already occurred."

Based on Medical News Today, it was simply revealed in 2014 that the transmission of BLV to humans is possible. BLV is a retrovirus and can cause contaminated cattle to build up malignant lymphoma and lymphosarcoma. Contaminated animals that have been open to the elements of BLV usually have virus antibodies in their milk of serum. The outlet added that it is unclear how BLV virus shows up in breast tissue, Buehring states that it may be through uncooked meat, drinking unpasteurized milk or it may spread from another person.