A new study shows gene flaws that raise the risk of breast cancer are surprisingly common in black women with the disease. This is the first comprehensive testing in this racial group.
The study found that one-fifth of these women have BRCA mutations, a problem usually associated with women of Eastern European Jewish descent but recently highlighted by the plight of Angelina Jolie
More than 230,000 women will be diagnosed with breast cancer this year, and gene flaws are part of the reason.
The study may help explain why black women have higher rates of breast cancer at young ages – and a worse chance of survival.
Doctors say these patients should be offered genetic counselling and may want to consider more frequent screening and prevention options, which can range from hormone-blocking pills to breast removal, as Jolie chose to do.
“We were surprised at our results,” said the study leader, Dr Jane Churpek, a cancer specialist at the University of Chicago. Too few black women have been included in genetic studies in the past and most have not looked for mutations to the degree this one did, “so we just don’t have a good sense” of how much risk there is, she said.
The findings suggest that broader genetic screening may be beneficial for high-risk black patients and their families. The study also suggests that family history is not the only criteria by which patients at risk for breast cancer can be identified.
The study results were presented at the 2013 Annual Meeting of the American Society of Clinical Oncology. The National Cancer Institute, the Breast Cancer Research Foundation and Komen for the Cure paid for the study.
The study involved 249 black breast cancer patients from Chicago area hospitals. Many had breast cancer at a young age, and half had a family history of the disease.
They were given complete gene sequencing for all 18 known breast cancer risk genes rather than the usual tests that just look for a few specific mutations in BRCA genes.
Gene flaws were found in 56, or 22 per cent, of study participants; 46 of them involved BRCA1 or BRCA2 and the rest were less commonly mutated genes.
Harmful mutations were found in 30 per cent of black women with “triple-negative breast cancer” – tumors whose growth is not fueled by estrogen, progesterone or the gene that the drug Herceptin targets. Doctors have long known that these harder-to-treat cases are more common in black women.
