The Pros And Cons Of Genetic Testing - Risk Factors: Breast Cancer

Content provided by the Faculty of the Harvard Medical School

The pros and cons of genetic testing

It has been estimated that nearly 12 percent of women may have a family history of breast cancer, generally defined as having several first degree relatives affected by the disease. The family factors that influence a woman's personal risk are the number of close relatives who also have the disease and younger age at onset of breast cancer. The presence of ovarian cancer in a mother or sister also increases breast cancer risk.

Of the possible genetic mutations that increase breast cancer (and ovarian cancer) risk, BRCA 1 and BRCA 2 have been studied the most. Abnormalities of one or both of these genes are usually inherited. But they also can occur sporadically.

Women who are Ashkenazi Jews with a family history of breast or ovarian cancer have an especially high risk of having a genetic mutation in BRCA.

Knowing that you are at a high risk for breast cancer may prompt you to consider genetic testing. When genetic testing is undertaken, it is generally looking for abnormalities in the BRCA genes. There are many types of mutations that can occur. Some, but not all, are associated with a greater chance of cancer development.

A woman who knows she carries the mutation can opt for rigorous surveillance, chemoprevention or prophylactic surgery.

A genetic test - taken by blood sample - gives you only insight into your odds; it can't tell you for certain whether you'll develop cancer or whether you'll be safe from it. Even if your genetic test doesn't find a BRCA mutation, you still face the risk any woman has for developing breast or ovarian cancer from other causes; mutation accounts for only a minority of breast cancers. And, even if you test positive for a BRCA mutation, you might not develop cancer.

If you are at high risk and are considering genetic testing for breast cancer, consult a genetics counselor. He or she can help determine the chances of a mutation in your family. Genetic counselors can also help you decide whether genetic testing is right for you, help interpret test results, and make referrals to support services if needed.

A genetics counselor can also discuss the potential implications of having the positive results of a genetic test in your medical record. Such a record could affect your ability to obtain health insurance, life insurance, and possibly employment.

Some women choose to pay out of pocket for genetic testing to avoid having the results entered into their medical insurance records. While the costs may vary, the fees charged by commercial sources of testing are in the thousands of dollars for testing one form of the BRCA1 gene. In one recent review, the cost was over $3000 dollars, with additional charges of several hundreds of dollars to test for further refinements of the gene abnormality.

Insurance carriers may cover the costs of testing, especially if medical documentation can be provided that states that specific treatment is likely to be advised based on the test results.

The National Cancer Institute maintains a directory of genetic counselors and physicians and nurses who have expertise in administering and interpreting these tests at www.nci.nih.gov or 1-800-4-CANCER.

Last updated:	April 23, 2007