Breast Cancer Breakthrough Explains Differences In Cancer Among Races, Possible New Therapies

In the fight against one of the deadliest forms of breast cancer for black women -- triple-negative breast cancer -- researchers at the North Shore-LIJ Health System and the Feinstein Institute for Medical Research in New York say they've made a significant breakthrough.

What they found: A new DNA marker linked to triple-negative breast cancer that's helping them to determine why African-American women often experience this more aggressive form of the disease, leading to a much lower survival rate than that of Caucasian women.

For the study, which was presented at the 2012 American Society of Clinical Oncology (ASCO) Annual Meeting, blood samples from 32 African-American and Caucasian patients -- 12 control patients and 20 women with a form of stage III breast cancer -- were examined before the removal of breast tumors.

Researchers tested the genetic markers embedded in DNA, called microRNA, and found that found Caucasian women who had triple-negative breast cancer showed levels of 20 different, cancer-fighting microRNA that were 15 times higher than the control group.

None of these microRNA were found in any of the African American patients.

"Breast cancer patients who have the most devastating outcome may carry the microRNAs that promote cancer," said Iuliana Shapira, director of the Cancer Genetics Program at the North Shore-LIJ Health System's Monter Cancer Center, according to Medical News Today. "What we saw in this study is that Caucasian women may carry microRNAs that protect against cancer while African-American women do not express those microRNAs," she added.

Similarly, a team of researchers in British Columbia, Alberta, the United States and the U.K. conducted a landmark study earlier this year mapping the genetic profile of triple-negative breast cancer, finding that no two genomes were similar, much less the same.

"These findings prove the importance of personalizing cancer drug treatment so that it targets the genetic make up of a particular tumour rather than presuming one therapy can treat multiple, similar-looking tumours," Steven Jones, co-author of the study, told the Canadian Press.

Shapira drew a similar conclusion from her study. "The striking difference in the patterns of microRNA expression between African American and Caucasian breast cancer patients may provide insight into answering why, when receiving similar treatments, outcomes are different between African Americans and Caucasians," she said.