A Duke University study has enhanced understanding of why breast cancer treatment works better for older women than it does for younger ones.
Researchers hope that the discovery could help scientists develop better ways to treat young breast cancer patients, defined as age 45 or younger.
Genetic factors, the comprehensive study found, are the primary contributors to young women's tumor development. Tumors in older women, age 65 or above, are linked to a much wider pool of possible causes.
Dr. Kimberly Blackwell, a breast oncologist at Duke University Medical Center and senior investigator on the study, said that clinicians have known for years that women under 45 tend to “respond less well to treatment and have higher recurrence rates than the disease we see in older women ….
“Now we're really understanding why this is the case, and by understanding this, we may be able to develop better and more targeted therapies to treat these younger women.”
Previous studies have shown that tumors in younger women, who represent about 15 percent of breast cancer patients, tend to be significantly more aggressive than those in women a few decades older.
The younger women's cancers are faster growing, and more resistant to treatment.
“It makes sense that there would be a more limited set of things that are contributing to young women's tumors,” Blackwell said. This influence tends to be related to underlying genetic problems, added Blackwell.
“It could be genetic mutation from diet, nutrition, environmental exposure,” she said.
The study, which was funded by the National Cancer Institute and published Thursday in the Journal of Clinical Oncology, found that the underlying difference between older and younger women's tumors was that younger women's tumors all looked pretty much the same genetically, whereas older women's were all different.
Blackwell hopes the results from her study will lead to increased scientific interest in young women with breast cancer.
“We could clearly differentiate between tumors in younger women and tumors in older women, and that is truly remarkable,” she said.
After examining over 13,000 genes each on 411 tumors, they found the same few hundred genes popping up over and over again in the young women's tumors.
“We were looking for which genes had a higher level of expression,” said Blackwell. A gene is said to “express” itself when it is being transcribed into something called RNA, a kind of genetic Xerox. The more RNA associated with a gene, the more active the gene being transcribed.
Lalania Hall, 37, was diagnosed with breast cancer last year. For Hall, who has five sons ranging in age from 3 to 12, being a part of the study was an experience of hope. “I'm so grateful that there are people out there who are starting to focus on younger women,” said Hall.
Dr. Steven Akman, an oncologist who heads the Breast Cancer Center of Excellence at Wake Forest University said that the analysis being done in the study appeared to be standard, but that that did not diminish the potential utility of the results.
“The question of why younger women's breast cancers are so aggressive is a really important question that we've known about for a long time,” said Akman. “What they're doing is providing a plausible biological way of looking at that question.”