Breast cancer is a much more complicated disease than had been thought, according to new findings by Duke scientists. Their research will provide a new framework for better understanding the biology of breast cancer and choosing the right treatments to fight it.
The research findings, which appear online in the Proceedings of the National Academy of Sciences, identify a new classification system for the disease.
Doctors have relied on characteristics such as the size of the tumor, stage of disease, hormone sensitivity and other factors to classify breast cancers. More recently, they've looked at the molecular classifications of the disease based on gene expression profiles, which are used to find and diagnose disease and see how well the body responds to treatment. But those profiles only tell part of the story, said Joseph Nevins, professor of breast cancer genomics in the Duke Institute for Genome Sciences & Policy and the paper's senior author.
The research found that patterns of gene expression in biological pathways activated in the development of breast cancer reveal many new subtypes of the disease.
Nevins and his research team gathered 1,143 gene expression profiles of breast tumors from ten independent studies. Making use of these signatures of pathway activation, the Duke researchers found that a pathway-based classification system identified 17 subgroups of breast cancer.
“The previously-identified subtypes were still evident in this pathway-based approach, but now with the additional information from our new classification system, we clearly see that breast cancer is more complex than we previously understood,” said Nevins.
For example, basal-type breast cancers are generally believed to be especially aggressive and hard to treat and are associated with lower survival rates. But in using the new classification system, the Duke researchers identified patients in one subtype who lived almost twice as long as the others.
Nevins said information gleaned from the new classification system could potentially be used to more carefully select patients for clinical trials testing new, targeted therapies.
To read more about the research and findings, go to dukehealth.org.