Researchers from the University of Chicago, working with colleagues at the University of Calabar in Nigeria and the University of North Carolina, found that breast cancers in African women produce a different pattern of gene expression. Tumors from African women -- from three locations in Nigeria and one in Senegal -- are more likely to originate from a different group of cells within the breast and often do not present the molecular targets that form the basis of many standard therapies.

"We have known for a long time that breast cancer is not one disease and that it may be somehow different in Africa," said study author Funmi Olopade, M.D., professor of medicine and director of the Center for Clinical Cancer Genetics at the University of Chicago. "But there was no real sense of how much of that was biology and how much was environment. Now we have clear evidence that nature plays an important role. These tumors are biologically quite different in ways that make this a worse disease."

"The discovery means we have to rethink how soon and how often we screen for breast cancer in women at risk for the most aggressive type of breast cancer, as well as how we prevent it and how we treat it," she added. "The guidelines were developed based on our deep knowledge of breast cancer in older women of European ancestry, but our results mean that much of the U.S. and European data simply do not apply to the types of breast cancer we most commonly see in African women."

The researchers studied the pattern of gene expression -- a measure of which genes were turned on and active -- in breast cancer tissue from 378 women in Nigeria and Senegal. They compared the results with a database of breast cancer tissue from
'"/>

Contact: John Easton
John.Easton@uchospitals.edu
773-702-6241
University of Chicago Medical Center
18-Apr-2005