African American women at risk of developing breast cancer are much less likely to receive genetic testing, according to a new US study. Researchers at the University of Pennsylvania looked at racial disparities in genetic counselling for an inherited susceptibility to breast and ovarian cancer. Their results, published in the Journal of the American Medical Association, showed that compared to white women with a family history of the disease, black women are 78 per cent less likely to undergo genetic counselling for this type of test. The reasons for this difference are unclear, say the team, but could include variation in quality of healthcare and mistrust of the medical profession.
Most cases of breast cancer are not inherited, but around 5-10 per cent are due to a gene mutation. Women who have a mutation in either the BRCA1 or BRCA2 gene have a greatly increased lifetime risk of developing breast and/or ovarian cancer. The study, carried out from December 1999 to August 2003, included 408 women with a family history of breast or ovarian cancer. Of these, 217 received genetic counselling for BRCA1/2 testing, while 191 women did not. The results showed that only 7.4 per cent of the women who received counselling were black, compared to 28.8 per cent of the women who did not receive counselling.
The association was still apparent after the team took into account factors such as socioeconomic status, women's perception of their own risk of breast and ovarian cancer, and whether or not their family doctor had recommended taking the test. Study leader Katrina Armstrong says that the lower rate of genetic testing in black women could be due to a greater distrust of healthcare, which has been shown in other studies. She concluded that 'the benefit of predictive genetic testing will not be fully realised unless these disparities can be addressed'.
US breast cancer researcher Olufunmilayo Olopade, who co-wrote an editorial accompanying the study, said that black women tend to underestimate their risk of breast cancer and lack awareness about BRCA gene mutations. Armstrong agreed, calling the situation 'a catch-22', adding: 'People are not receiving genetic counselling because there is not enough information about how frequently these mutations occur in the African-American community'. Such counselling is important, she said, because women with BRCA1/2 mutations can take pre-emptive steps such as taking the drug tamoxifen or undergoing preventative mastectomies.