It has been well known for a long time that the risk of a breast cancer developing increases as a woman ages, with most women being diagnosed today over the age of 50. Why this is, however, has remained a mystery, until now.
Research was conducted at an unusual place--the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab)--where molecular biologists have been studying this question for a while--and the scientists have now cracked this egg.
Here's the scoop
By studying tissues harvested from mastectomy specimens and breast-reduction specimens (with the patients’ approval, of course), the scientists determined that aging in women causes an increase in something called multipotent progenitors--a type of adult stem cell now believed to be the root cause of many breast cancers. A decrease in the myoepithelial cells that line the breast's milk-producing luminal cells, and that act as tumor suppressors, contributes to the increase in breast cancer risk.
In laymen's terms, this means that one of the cells within the breast ducts, a cell that’s designed to protect the breast tissue from developing mutated cells, simply goes away as we age. And when it goes away, or is at least diminished as we age, the breast tissue, and in particular the lining of the breast ducts where the majority of breast cancers grow, becomes more vulnerable to harmful mutations. When you think about it, this is probably the reason why 75 percent of breast cancers are diagnosed in women who are over the age of 50.
What can we do about this?
So how can we prevent this from being part of our aging process? That will be the next research question for scientists to solve.