Who Should be Tested for the BRCA Gene Mutations?
- Advantages and Disadvantages to Genetic Testing for BRCA Mutations
- Additional Resources and References
Every woman is born with the BRCA1 (breast cancer gene 1) and BRCA2 (breast cancer gene 2) genes. When functioning normally, these genes do not pose any risk to a woman's health. However, some women may be born with or experience mutations of the BRCA genes through their lifetime. Though researchers are still uncertain what causes changes in these genes to occur, women who have BRCA mutations are at increased risk for developing breast cancer compared with women who do not have these mutations. For example, a 30-year-old woman with a BRCA mutation has a 1 in 3 chance of developing breast cancer during her lifetime (compared with a 1 in 8 chance for women without these genetic mutations). Over a lifetime, women with BRCA mutations have a 50% to an 85% chance of developing breast cancer.
In 1996, the American Society of Clinical Oncology recommended that only women with a strong family history of breast cancer or those who have developed breast cancer at an early age may be eligible for BRCA genetic testing and most physicians still adhere to this recommendation today. Candidates for BRCA testing include those women with:
- Breast cancer in two or more close relatives, such as a mother and two sisters
- Early onset of breast cancer in family members, often before age 50
- History of breast cancer in more than one generation
- Cancer in both breasts in one or more family members
- Frequent occurrence of ovarian cancer
- One or more BRCA positive relatives
- Eastern and Central European (Ashkenazi) Jewish ancestry, with a family history of breast and/or ovarian cancer (researchers have identified two types of BRCA1 mutations and one BRCA2 mutation that are especially prominent in this group)
Though many women who have already developed breast cancer do not see the need to be tested for BRCA mutations, benefits of knowing may include: better response to treatment designed for BRCA-positive women and helping other family members to take preventive measures against breast cancer.
Genetic Testing Process
Step 1: counseling session
Step 2: blood is drawn and analyzed
Step 3: test results are discussed
The first step involves genetic counseling. In this session, a counselor will discuss the tests, possible risks (such as psychological effects, employer concerns, insurance difficulties), and what a positive or negative result means. During the second session, the blood test and genetic analysis will be performed. At the third session, the results of the test will be discussed with the patient. Most genetic testing is anonymous; women do not give out their name and are randomly assigned a number for identification and future contact.