It’s been said time and time again that triple-negative breast cancer is more common in Black American women when compared to other groups. Recently researchers have discovered that it actually depends on where Black women are born, so not all Black women have the same level of risk.
The American Cancer Society (ACS) researchers found that Black women, specifically those born in the United States and Western Africa were diagnosed more often with triple-negative breast cancer than women born in East Africa. This study’s findings were published in the ACS peer-reviewed journal, Cancer.
As seen on American Cancer Society.
Previous studies have reported that black women in the US are twice as likely as white women to be diagnosed with triple-negative breast cancer. This study, however, suggests that saying that all black women have a higher risk of being diagnosed with this cancer type may be too general of a statement.
Using the National Program of Cancer Registries, the ACS researchers identified 65,211 non-Hispanic black women who were diagnosed with invasive breast cancer from 2010 to 2015. The women were recorded as being born in the US, East Africa, West Africa, or the Caribbean.
Compared with the prevalence of triple-negative breast cancer among black women born in the US, black women born in:
-West Africa had similar rates to black women born in the US
-The Caribbean had a 13% lower prevalence
-East Africa had a 47% lower prevalence
There wasn’t enough data to analyze the prevalence rates of black women born in North, Central, or South Africa. This is one of the few studies to examine how place of birth relates to black women’s risk of breast cancer.
It’s not clear what risk factors for developing breast cancer may be associated with birthplace. The differences could be due to genetics. Most black women born in the US or in the Caribbean are likely descendants of people who were involuntarily migrated from West Africa to North America during the 16th to 18th centuries, often through the Caribbean.
Ancestry studies among black people living in Chicago, Baltimore, Pittsburgh, and North Carolina reflect the historic migration. Ancestry in those places is 71% Western African. The differences could also be due to risks from values, traditions, social structures, income, or health behaviors, such as eating a western diet.
“Our results tell us that knowledge based on such a broad categorization of black versus white women may mask the complexity of the differences in breast cancer that appeared to be present within black women,” says Hyuna Sung, PhD, a principal scientist in surveillance research at the ACS and lead author on this study.
The main limitation of the study was missing information about birthplace. The researchers say it’s important to take birthplace into consideration when studying different types of breast cancer in women of African descent in the US and other parts of the world. This could help cancer experts better understand the diversity of breast cancer among black women. The authors say their study “calls for a concerted effort for more complete collection of birthplace information in cancer registries.”
Sources
https://www.cancer.org/latest-news/all-black-women-in-united-states-may-not-have-same-risk-for-triple-negative-breast-cancer.html