A new study published in JAMA Network Open has found that Ghanaian women and U.S. non-Hispanic Black women have nearly identical rates of estrogen receptor (ER)-negative breast cancer, an aggressive type of breast cancer, suggesting possible shared biological or environmental risk factors linked to West African ancestry.

A cross-sectional study comparing breast cancer incidence among Ghanaian and U.S. women has revealed that Ghanaian women and U.S. non-Hispanic Black women experience similar rates of estrogen receptor (ER)-negative breast tumours, while both groups have higher rates than U.S. non-Hispanic White women.

Significantly, Prof. Daniel Ansong of the Kwame Nkrumah University of Science and Technology (KNUST), Kumasi was among the distinguished co-authors of this study.

The study, published in JAMA Network Open, analyzed data from 1,071 Ghanaian women aged 18 to 74 years and more than 121,000 women in the United States collected between 2013 and 2015.

Researchers found that the age-standardized incidence rate of ER-negative breast cancer was 42.3 per 100,000 women in Ghana and 43.1 per 100,000 among U.S. non-Hispanic Black women. Both figures were substantially higher than the 24.0 per 100,000 recorded among U.S. non-Hispanic White women.

In contrast, ER-positive breast cancer, a more treatable form was far less common in Ghana, with an incidence rate of 42.1 per 100,000, compared with 105.4 for U.S. non-Hispanic Black women and 128.5 for White women.

The findings, led by Dr. Brittny C. Davis Lynn and colleagues from the National Cancer Institute and the Ghana Health Service, suggest that women of West African ancestry may share underlying factors predisposing them to ER-negative breast cancer.

“Understanding these shared susceptibilities is crucial to improving prevention and treatment outcomes for women of African descent globally,” the authors wrote.

ER-negative tumours tend to occur at younger ages and are often more aggressive than ER-positive types, highlighting the need for tailored screening and awareness strategies, particularly in African populations where such data have been limited.

The researchers called for further studies to identify genetic, environmental, or lifestyle factors contributing to the higher prevalence of ER-negative breast cancer in women of African ancestry.