A significant difference in genes between sub-Saharan African women and white women of European ancestry seems linked to the finding that Black women have a higher incidence of, and a higher mortality from Triple Negative Breast Cancer.
In an American study, published in JAMA (1), African American women with non-metastatic Triple Negative Breast Cancer had a significantly higher risk of breast cancer mortality when compared with an equivalent group of white women. Black women were 28 percent more likely to die, even though they had the same diagnosis. This was only partially explained by a lower level of surgery and chemotherapy through location or choice. This was a population based study with a review of a cohort of 23,213 patients with TNBC.
Now a new study (2) from Weill Cornell Medicine has shown that women with African links have a clear genetic link to this rarer form of breast cancer. Inside Africa, TNBC patients are approximately 33 percent of total breast cancer patients; whereas the risk of developing TNBC in the USA is 20 percent of total. But the women of African ancestry in America do have a higher risk of mortality than white Americans of European ancestry. Next, the scientists showed more than 2,000 genes were linked with regional sub-Saharan African ancestry in patients with TNBC. These differ significantly from those of white women with European Ancestry. And finally they showed that depending upon the region of original existence within Africa, Black women had more or less immune cells inside their TNBC tumours.
The significance of this finding for treatment, and particularly immunotherapy, is yet to be examined.
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