A newly published study shows that African-American women are more likely than their white, Asian, or Hispanic counterparts to have the inherited gene mutations that increase breast cancer risk.
The recent flurry of media attention on Angelina Jolie and her double mastectomy alerted many women, perhaps for the first time, to the possibility of genetic susceptibility to breast cancer.
Sure, we’re all familiar with the “family history” connection to medical conditions: heart issues, high blood pressure, depression, all can be “passed along” from parents to children. As can breast cancer risk.
In recent years, researchers have begun identifying specific genes and gene combinations that increase breast cancer risk to sometimes astronomical levels: up to nearly 90%, for some unlucky women.
The BRCA1 and BRCA2 gene mutations are two genetic indicators that have been known to science for quite some time. And while they’re present in less than 1% of the general population (and about 2.4% of those diagnosed with breast cancer), their effect on breast cancer risk is so great that they get a lot of attention – especially since Angelina’s story hit the wires.
Now, a study published June 6 in the online Journal of Clinical Oncology reveals that African-American women are much, much more likely to carry these gene mutations than women of other races. The study adds to the growing body of evidence that points to African-American women being diagnosed with breast cancer at an earlier age, and suffering a worse outcome, than most other women.
The small but significant study, carried out on 249 African-American women diagnosed with breast cancer, revealed that fully 19% of them carried either or both of the BRCA genes. Compare this to 2.4% of all women diagnosed with breast cancer who carry the gene(s); clearly, the disparity is huge.
And potentially deadly. Triple negative breast cancer (TNBC), a type unresponsive to hormone therapy; and breast cancer diagnosed under age 45 have higher mortality rates than other diagnoses. And 30% of the women in the study who had TNBC also carried the mutant genes; while 27% of younger (under age 45) patients had the genes.
In addition, almost half of those who had two separate, unrelated breast cancer diagnoses; and 30% with a significant family history of breast or ovarian cancer were gene carriers.
The study’s conclusion? “These high carrier frequencies suggest the importance of screening for mutations in all breast cancer genes in all AA [African-American] breast cancer patients diagnosed at a young age, with a family history, or with TNBC as a way to identify at-risk family members for life-saving interventions.” (Churpek, 2013)
The study’s lead author, Jane Churpek, M.D., a hematologist/oncologist from the University of Chicago, commented that the genetic screening necessary to identify carriers of the known range of dangerous genes can be difficult.