Hispanic women may be partially protected from breast cancer by a genetic variant carried by 20 percent of that population.
University of California San Francisco (UCSF) researchers determined the genetic change, which makes up just one "letter" among three billion in the human genome.
This single-nucleotide polymorphism (SNP) is capable of conferring a great deal of protection from breast cancer for those women who exhibit the variation. It is found on Chromosome 6, close to a gene which codes for an estrogen receptor called ESR1.
"If you have one copy of this variant, which is the case for approximately 20 percent of U.S. Latinas, you are about 40 percent less likely to have breast cancer. If you have two copies, which occurs in approximately 1 percent of the US Latina population, the reduction in risk is on the order of 80 percent," Elad Ziv, professor of medicine at UCSF and senior author of an article announcing the results of the study, said.
Ziv and his team looked at breast cancer data from several studies to determine the rate at which the disease developed among various populations of women worldwide. At first, the team believed those of European descent may have a genetic variant, but it was later found the gene developed in Hispanic women. The study as a whole examined records of 3,140 women with the disease, as well as 8,184 without cancer, who served as controls in the investigation.
Medical researchers have long known that Hispanic women develop breast cancer less often than other ethnic groups. Less than 10 percent of Latino women develop breast cancer at some point in their lives, compared to 11 percent among African-Americans and 13 percent of Caucasians.
The team is currently studying other factors which could increase or decrease the possibility of breast cancer risk among Latino women. They hope that such study will allow the development of new risk assessment plans that could better assist in during the screening process.
"This work was done as a collaboration of multiple investigators, many of us originally from Latin America. As a Latina myself, I am gratified that there are representatives of that population directly involved in research that concerns them," Laura Fejerman, assistant professor of medicine at the university, told reporters in a press release.
Discovery of the link between breast cancer and the genetic variant found in many Hispanic women was detailed in the journal Nature Communications.
