October is Breast Cancer Awareness Month, and while this is an important time to focus on breast cancer education, it is also the opportune time to take a look at the latest discoveries for the disease.
For Latinas, who typically have fewer cases of breast cancer compared to non-Hispanic whites, Breast Cancer Awareness Month doesn’t always hold meaning like it does for other groups in the United States. But just because breast cancer isn’t as common in Latinas doesn’t mean it is any less deadly.
In fact, breast cancer is still the most common cancer diagnosed in Latinas, according to the American Cancer Society, and Latinas are more likely than non-Hispanic white women to have their breast cancer diagnosed during later, more complicated stages.
That being said, the numbers have remained steady; Latinas simply don’t get breast cancer at the same frequency of non-Hispanic whites, and now, the latest breast cancer research might have uncovered why.
Data from University of California, San Francisco (UCSF) research suggests women of Latin American descent, particularly those with indigenous ancestry, may carry a genetic variant that protects them from breast cancer.
“We have detected something that is definitely relevant to the health of Latinas, who represent a large percentage of the population in California, and of other states such as Texas, said first author Laura Fejerman, PhD, in a university press release. 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.
Fejerman, fellow author Elad Ziv, MD, and their research team have long suspected there was a genetic reason Latinas were less likely to be diagnosed with breast cancer compared to other women. For several years they searched for such a variant within DNA, eventually combining their data from the earlier Womens Health Initiative study and a study conducted in Mexico to identify a single genetic variant that grants significant protection for Latinas against breast cancer.
The variant is known as a single-nucleotide polymorphism (SNP), meaning it is a difference in just one of the three billion letters in the human genome, and experts indicate it not only provides significant protection against breast cancer in general, it is particularly beneficial in Latinas who are prone to more aggressive estrogen receptornegative forms of the disease.
“The effect is quite significant, said Ziv. 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.
Fejerman and Ziv identified the genetic variant on Chromosome 6, near a gene coding for an estrogen receptor known as ESR1. Though the exact reason the variant reduces breast cancer risk is not yet known, the team says preliminary findings suggest the SNP interferes with the regulation and expression of ESR1.
If we can use these results to better understand how this protects estrogen receptor-negative breast cancer, that would be interesting and important, Ziv said, because right now we have no good way to prevent that type of breast cancer.
Though Hispanic women have a lower rate of breast cancer in general, they have the highest rate of triple-negative breast cancer–the most aggressive and deadly form of breast cancer. According to the National Library of Medicine, not only do Hispanic women have higher rates of triple-negative breast cancer, they also are diagnosed at earlier ages as many as 11 years earlier but in more advanced disease stages. The new genetic discovery may one day provide medical experts with a way to treat the risk for this disease through genetic therapy.