Approximately 5% to 10% of breast cancer cases are associated with inherited gene mutations. For this reason, many women from high-risk families, in which multiple first- and second-degree relatives (mother, sister, daughter, grandmother, aunt) develop breast cancer, are advised to undergo genetic testing for cancer-promoting mutations in the so-called BRCA1 and BRCA2 genes. But research on the effectiveness of genetic testing has been limited in the African American population, in which there is a higher incidence of breast cancer in younger women.

A new study in the October 19, 2005 issue of the Journal of the American Medical Association , compared the effectiveness of genetic testing in European Americans with African Americans and found that genetic counseling and genetic testing are useful screening tools in the high-risk African American population.

About the Study

This study included 150 families (78 white, 43 African American, and 29 Ashkenazi Jewish) with two or more cases of breast cancer and/or ovarian cancer among first- and second-degree relatives. The researchers used BRCAPRO, which is a risk assessment tool that predicts the participants’ likelihood of carrying BRCA1 or BRCA2 gene mutations on the basis of family history information. The participants’ underwent genetic testing for BRCA1 and BRCA2 gene mutations. Participants were classified as having a known cancer-promoting mutation, indeterminant mutations (a genetic change as yet unassociated with breast cancer) or no mutation. The researchers compared the use of BRCAPRO and genetic testing among the different ethnic groups.

Overall, 46% of white families, 28% of African American families, and 69% of Ashkenazi Jewish families had BRCA1 or BRCA2 cancer-promoting mutations. The researchers found that African Americans had a lower rate of cancer-promoting mutations (28% versus 46%), but a higher rate of indeterminant mutations (44% versus 11%) than whites. In African Americans, BRCAPRO underestimated breast cancer risk at the lowest levels, and overestimated it at the highest levels. However, in discriminating between the women with a mutation and those without, BRCAPRO performed equally well in all ethnic groups.

How Does This Affect You?

These findings suggest that genetic counseling and testing for breast cancer is beneficial in the African American population. This is especially important, considering that research has found that African American women with a family history of breast cancer are significantly less likely than white women to undergo genetic counseling and BRCA1 / BRCA2 testing.

If you are an African American woman with a family history of breast cancer, you should discuss genetic counseling and testing with your physician. Finding out if your genes put you at risk for developing breast cancer later in life can provide you with the information you’ll need to consider prevention strategies, such as having surgery before breast cancer occurs or participating in an intensive screening regimen.