June 13 (UPI) — Black women born in the United States have a higher rate of triple-negative breast cancer than black women who are U.S. citizens born in Eastern and Western Africa, and the Caribbean, a study says.
This research, published Thursday in the journal Cancer, suggests not all black women have disproportionately higher triple-negative breast cancer rates compared to other racial or ethnic groups.
“It is not clear what risk factors conferred by birthplace are associated with subtype prevalence,” Hyuna Sung, a researcher at the American Cancer Society and study author, said in a news release. “However, the similarity in breast cancer subtype prevalence between U.S.-born and Western-African-born blacks, contrasted against the differences with Eastern-African-born blacks, may in part reflect shared ancestry-related risk factors.”
The researchers analyzed data from the National Program of Cancer Registries and the CDC’s U.S. Cancer Statistics program. They identified more than 65,000 non-Hispanic black women who were born in either the United States, East Africa, West Africa or the Caribbean, and were diagnosed with invasive breast cancer between 2010 and 2015.
As of 2013, records show roughly 9 percent of the U.S. black population was born outside of the country, according to the researchers. About half of that number were born in the Caribbean, while 35 percent were born in Sub-Saharan Africa and 9 percent came from Central and South America.
In contrast to black women born in the United States, the prevalence rate ratio of triple-negative breast cancer risk was 46 percent lower in Eastern-African-born black women, 13 percent lower in Caribbean-born women and 8 percent lower in Western-African-born women.
Triple-negative breast cancer is usually more aggressive and harder to treat than other forms. In the United States, it’s twice as prevalent in black women compared to white women.
However, the influx of black immigrants into the United States over the last few decades has created subgroups of women with varying rates of breast cancer occurrences and properly understanding those subgroups may help to improve screening and treatment for the disease.
“Presenting breast tumor subtype in black women as a single category is not reflective of the diverse black populations in the nation,” the authors wrote.