SAN ANTONIO, Dec. 15 (UPI) -- Dense breast tissue contains more cells believed to give rise to breast cancer, compared to non-dense tissue, U.S. researchers said.
Dr. Karthik Ghosh, a Mayo Clinic breast cancer researcher, said researchers found a dramatic difference in tissue composition between dense and non-dense tissue in the breast.
In a second study, Celine Vachon, also of the Mayo Clinic, found that dense breast tissue has more aromatase enzyme than non-dense tissue.
This is significant because aromatase helps convert androgen hormones into estrogen, and estrogen is important in breast cancer development, Vachon said.
"If aromatase is differentially expressed in dense and non-dense breast tissue, this could provide one mechanism by which density may increase breast cancer risk," Vachon said in a statement.
Sixty women, ages 40 to 85, allowed Mayo Clinic researchers to take eight core-needle biopsies from their breasts -- none had a history of breast cancer.
"These are initial findings from one of the first attempts to study breast density at the level of healthy tissue. It doesn't explain everything yet, but is providing really valuable insights," Ghosh said.
The two studies were presented simultaneously at the Cancer Therapy & Research Center-American Association for Cancer Research in San Antonio Breast Cancer Symposium.
