BOSTON, Aug. 1 (UPI) -- More than 90 percent of the world's population has Epstein-Barr virus, often with no effects, but new research suggests it may increase risk for breast cancer among some women.
Researchers at Beth Israel Deaconess Medical Center report breast cells exposed to the virus show characteristics linked to breast cancer, and exposure may accelerate its formation, making the potential benefit of a vaccine particularly useful.
EBV was one of the first viruses found to cause cancer, and is linked to about 200,000 cases of the disease per year. While a link to breast cancer has been suspected, the virus is already linked to African Burkitt lymphoma, Hodgkin's disease, nasopharyngeal carcinoma and gastric adenocarcinoma.
Although studies have previously suggested a link to breast cancer, researchers involved with the new study say a definitive link from virus to disease had not previously been observed.
"We think that if a young woman develops EBV during her teenage years or later, her breast epithelial cells will be exposed to the virus and can be infected. While for most individuals, there will be no long-term consequences, in some the infection may leave genetic scars and change the metabolism of these cells," Dr. Gerburg Wulf, a researcher at Beth Israel and associate professor at Harvard Medical School, said in a press release. "While these are subtle changes, they may, decades later, facilitate breast cancer formation."
For the study, published in the journal EBioMedicine, researchers cultured primary mammary epithelial cells in the presence of EBV, finding the virus binds to a receptor on normal breast cells, infecting them.
When the cells, which began to take on the characteristics of stem cells after infection, were implanted into mice, changes to the cell and the infections' interaction with certain proteins caused the start of breast cancer.
A vaccine against the virus would prevent not only infection, which is commonly linked to the development of mononucleosis, but could prevent cancers linked to it, including breast cancer.
"The findings further make the case for an EBV vaccine that might protect children from infection and later EBV-associated malignancies," Wulf said.