Cellular changes explain greater breast cancer risk in older women

Berkeley Lab scientists appear to have uncovered cellular changes that explain why women over 50 face a heightened risk of breast cancer. They blame an age-related spike in a type of adult stem cell that appears to be connected to many forms of the disease, and the declining numbers of another type of cell that they believe ordinarily helps to suppress tumors. The journal Cancer Research has published the study in detail.

"This is a big step towards understanding the cellular basis for age-related vulnerability to breast cancer," lead researcher Mark LaBarge, a cell and molecular biologist at the Berkeley Lab's life sciences division, said in a statement.

LaBarge used a cell-culture system co-author Martha Stampfer and colleagues had developed to study human mammary epithelial cells taken from primary tissue in women ages 16 to 91. (The samples came from mastectomies and cosmetic reduction surgery discards, as well as frozen samples Stampfer acquired 30 years ago to use in breast cancer research.)

Essentially, they discovered that aging boosts the number of adult stem cells known as multipotent progenitors, which are thought to be the culprit behind many types of breast cancers. At the same time, the team realized that the aging process leads to a big drop in the number of myoepithelial cells lining the milk-producing luminal cells in the breast. This is crucial, too, the researchers explain, because these cells are thought to help suppress tumors.

While more research is necessary, the researchers say their finding takes a huge step toward advancing breast cancer treatment. It is true that scientists have previously connected age-related physiological changes to increased breast cancer risks. But uncovering the cellular processes behind the changes and why they connect to breast cancer is something that hasn't been widely addressed until now, the research team asserts.

Armed with this new knowledge--understanding how patients become more vulnerable to the disease on a cellular level as they age--subsequent work can focus on finding treatments that help either avoid or reverse those changes. There is plenty at stake, as the researchers note, considering that more than 200,000 women in the U.S. are diagnosed with invasive breast cancer annually and about 75% of those patients are above age 50.

- here's the release
- check out the journal abstract