Research News on Risk and Genetics
Research has shown that women with a family history of breast cancer have a higher risk for developing the disease. That's true whether the family history is on the mother's side or the father's. And it's especially true if the women in the family were diagnosed with the disease before the age of 50.
Some women with a strong family history of the disease have inherited a specific gene abnormality that increases their risk for breast cancer. So far, abnormalities that have been found to have a definite link to an increased risk for breast cancer are in the BRCA1 and BRCA2 genes.
Women who learn through genetic testing that they have abnormal BRCA1 or BRCA2 genes face very difficult decisions. Past studies have shown that for such women, breast cancer risk could be as high as 80% to 90% by the age of 70. With such a high risk, many women decide to take preventive measures, including mastectomy, double mastectomy, ovary removal, and tamoxifen therapy. These are all very serious measures that can significantly change a woman's life.
In this section, you can read more about recent research on preventive treatment for women with the BRCA1 and BRCA2 gene abnormalities, including ovary removal, and double mastectomy.
You can also read research reports on how high the risk for women with BRCA1 and BRCA2 gene abnormalities actually is, and on another gene abnormality that has a strong link to breast cancer.
These research reports are part of the breastcancer.org monthly Research News program. Each month, our experts examine recent breast cancer research for exciting advances, important updates, and changes in how breast cancer is treated and diagnosed.
We present these studies in easy-to-understand language, explaining their importance, how they were conducted, and what impact the results might have for YOU.
Testing for abnormal breast cancer genes started in 1996, but little research has been done on who gets tested and why. And those studies have included mostly white women. Researchers aren't sure if this is because white women are more likely to have hereditary breast cancer or are more likely to seek genetic testing, or because there is racial disparity in how the tests are used. Racial disparity means that people are more (or less) likely to be given particular treatments because of their race.
Racial disparities in other areas of health care have been documented in the past. Because these inequalities may be greatest for new technologies, the researchers thought that genetic counseling for BRCA1 and BRCA2 testing might be affected.
Abnormal BRCA1 and BRCA2 (BR stands for BReast, and CA stands for CAncer) genes account for about 5–10% of all breast cancers. The average woman (without an inherited abnormal breast cancer gene) in the United States has about a 12% risk of developing breast cancer over a 90-year life span.
Women who have an abnormal BRCA1 or BRCA2 gene have up to an 85% risk of developing breast cancer by age 70. Women with BRCA1 or BRCA2 abnormalities are also at increased risk of developing ovarian cancer. The lifetime risk for ovarian cancer is about 55% for women with BRCA1 mutations and about 25% for women with BRCA2 mutations. By comparison, about 1.8% of women without an inherited BRCA gene abnormality get ovarian cancer.
In the study reviewed here, researchers from the University of Pennsylvania looked at race and the use of counseling for BRCA1 and BRCA2 testing among women with a family history of breast or ovarian cancer. They also wanted to see if factors such as age, education, and income, as well as worry about and perceptions of breast cancer, influenced whether women of different races had counseling for BRCA1 and BRCA2 testing.
The researchers looked at genetic counseling rather than genetic testing because they were interested in who gets referred for testing, not who decides to have testing after they've been counseled. In this study, about three quarters of the women who received genetic counseling did later have testing for BRCA1/2 abnormalities.
