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 is Usually a Three-Step Process

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.

Testing BRCA Positive

Women who test positive for BRCA mutations are at a higher risk for breast cancer. Consequently, relatives of these women may also be at increased risk for breast cancer BRCA-positive women should practice monthly breast self-examination, have frequent clinical breast exams (at least once a year), and have a yearly mammogram so that if breast cancer is detected, it may be treated at an early stage. BRCA-positive women should also talk to their physician about beginning screening mammogram at an earlier age, maybe even as early as 25.

In addition to breast cancer screening, women who test positive for BRCA mutations should consider lifestyle changes such as eating healthier, limiting alcohol consumption, exercising, and maintaining a healthy weight. Women may also consider breast cancer prevention with the drug tamoxifen or prophylactic mastectomy (preventive removal of the breasts). However, physicians do not usually recommend prophylactic mastectomy since testing positive for BRCA mutations does not guarantee that a woman will develop breast cancer. Click here to learn more about preventing breast cancer in BRCA positive women.

Advantages and Disadvantages to Genetic Testing for BRCA Mutations

Genetic testing has been a controversial topic among medical professionals for several years now. Women with a strong family history of breast and/or ovarian cancer should weigh the advantages and disadvantages of genetic testing carefully before reaching a decision. Though most testing centers require genetic counseling prior to testing, all women considering genetic testing should discuss their situation with a counselor or physician.

Advantages to testing for BRCA mutations:

• Women may feel relieved knowing for certain whether or not they are at a higher risk for breast cancer.
• Women with breast cancer may have better responses to certain treatments that are specifically designed for BRCA positive patients.
• Women may take preventive measures to help reduce their risk of breast cancer if they test positive for BRCA mutations (such as making changes in diet, exercising, or taking tamoxifen).
• Other family members may decide if they wish to be tested for BRCA mutations based on the results of a woman’s test. (However, testing positive for BRCA mutations does not necessarily mean a woman will develop breast cancer. She is at higher than average risk for the disease, though).

Disadvantages to testing for BRCA mutations:

• Women may become worried, panicked, or stressed if they discover they have a higher than average risk for breast cancer.
• Women who test positive for BRCA mutations are faced with the difficulty of telling family members (some of whom may also be at increased risk for breast cancer).
• Women who test negative for BRCA mutations may falsely believe they will never get breast cancer.
• Women who test positive for BRCA mutations may have to deal with complications with health insurance (if they are not tested anonymously)
• To date, no studies show that health insurance providers will reduce coverage or cancel a policy based on genetic test results. However, women should be made aware of the possibility.

Regardless of the test results, all women should still take preventive measures to help reduce their risk of breast cancer. These preventive measures include: practicing monthly breast self-examination, having regular clinical breast exams, and having yearly mammograms (at 40 years of age and older). Though testing from BRCA mutations may help identify women who are at a higher risk for breast cancer, 80% of women who develop breast cancer have no known risk factors.

Most physicians recommend against BRCA testing if a woman is not ready to take specific action if she tests positive. Tamoxifen may be used to help prevent breast cancer without knowledge of specific gene mutations.

Additional Resources and References

• To learn more about BRCA mutations and other genetic risks for breast cancer, please visit http://www.imaginis.com/breasthealth/genetic_risks.asp
• The Mayo Clinic offers information on BRCA gene mutations and genetic testing at http://www.mayoclinic.com/.
• FORCE (Facing Our Risk of Cancer Empowered) provides information and support at http://www.facingourrisk.org
• Dr. Deborah Axelrod, MD and Breast Specialist, provides detailed information on inherited breast cancer at http://www.breastdoc.com/
• For additional information on risk factors for breast cancer, please visit http://www.imaginis.com/breasthealth/bc_risks.asp.

Updated: December 17, 2007

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