After reviewing more than 7,000 cancer tissues, the correlation between hormones and aging in how breast cancer develops is now better understood.

It is widely known that age affects a person’s likelihood of receiving a cancer diagnosis, including breast cancer. A study published on Monday, May 11th in Nature Cancer​, highlights a better understanding of the relationship not only between age and breast cancer but also between age related changes in estrogen in the development of breast cancer. ​

“What this study is doing for the first time is really finding out how much of our genomes are affected by estrogen and how much is possibly affected by other factors during ageing,” says BC Cancer and University of British Columbia research Dr. Sam Aparicio. “What the study set out to do was to try and separate those two things.” 

The study also highlights how age affects the some of the diagnostic biomarkers that pathologists use to assess breast cancers during treatment planning. Among the novel findings a protein that gives cells in our bodies memory of their identity was found to be regulated by estrogen -- a key finding that may open new understanding of how breast cancers arise.

The study breaks down the degree to which breast cancer is affected by a reduction of estrogen and what is due to other natural aging factors that occur within cells. By teasing this information out of a large set of data on a completely uniform scale, researchers are in a better position to understand the different ways that aging contributes to breast cancer. The implications of these learnings are far reaching.

“Age is so clearly a factor in the way genes get expressed in our lifetimes it means that perhaps we need to look more closely at the way we incorporate age into diagnostic testing,” says Dr. Aparicio. “It points to this being specifically important for estrogen-related factors which we didn’t quite appreciate before.”

Another unique factor uncovered by this research was the finding of a small number of genes that appear to be estrogen-regulated in lung cancers, an avenue that will require further research to better understand.

These discoveries were made possible by the generous and ongoing support of BC Cancer Foundation donors.