Women under age 40 account for only 5% of breast cancer cases, but when it strikes the disease is often more aggressive. Now scientists at Duke University have found genetic evidence that suggests tumors in younger women have specific personality traits.
"I think it really for the first time offers some biologic definition as to why younger women with breast cancer do not do as well as older women who develop breast cancer. Hopefully we will be able to develop smarter therapies as opposed to more aggressive therapies. The most important message is that even if a woman does not have a family history of breast cancer she should take a new breast lump seriously and seek medical attention," said Kim Blackwell, M.D., Duke University Medical Center.
Dr. Blackwell says her team of researchers at Duke is now working on understanding the differences that come with breast cancer at certain ages so they can create tailor made treatments.
Duke researchers looked at samples of nearly 800 breast tumors from women in five countries on three continents, and divided them into age-specific cohorts. The investigators found more than 350 sets of genes that were active only in the tumors from women under age 45. Conversely, tumors arising in women over age 65 did not share these activated gene sets.
The breast tumors that arose in younger women shared a common biology, and this discovery was truly remarkable. The genes that regulate things like immune function, oxygen supply and mutations that we know are related to breast cancer, such as BRCA1, were preferentially expressed in the tumors taken from younger women, but when we compared younger women's tumors to older women's tumors, we found those same gene sets were not expressed in the 'older' tumors.
Researchers have already developed compounds that target some of the activated gene expression pathways that the Duke team discovered, and many of these compounds have promise for combating young women's tumors, Blackwell said. Identifying these characteristic gene expression profiles will be an important part of finding new therapies, she said.
Researchers say many of the gene sets seen in 'younger' tumors distinguished these cancers from 'older' tumors but the reverse was not true -- there was nothing we saw in the older women's tumors that set them apart genomically. Researchers say identifying these distinguishing characteristics may be the first step in developing more effective treatments for these younger patients.