Compared with women of European or African-American descent, fewer Hispanic women develop breast cancer and fewer of them die from it, medical statistics show, and an international team led by researchers at the University of California, San Francisco, recently said they now know the reason why this is.
A tiny difference in the DNA of certain women makes Latinas who inherit it about 40% less likely to develop breast cancer, medical geneticist Laura Fejerman and her colleagues reported in Nature Communications. And, if women have inherited the variation from both sides of their family, they are 80% less likely to get breast cancer.
“It is strongly protective,” said cancer specialist Elad Ziv at the UCSF Helen Diller Family Comprehensive Cancer Center, who helped conduct the study funded by the National Cancer Institute. “We really need to do more experiments to nail it down and understand what it is doing.”
Women who carry the genetic variant have breast tissue that appears less dense on mammograms. High-density breast tissue is a known risk factor for breast cancer.
The finding may lead to more effective genetic testing for women at risk, by helping to determine who most needs to take preventative measures.