6. How do people know if they should consider genetic testing for BRCA1 and BRCA2 mutations?

Currently, there are no standard criteria for recommending or referring someone for BRCA1 or BRCA2 mutation testing.

In a family with a history of breast and/or ovarian cancer, it may be most informative to first test a family member who has breast or ovarian cancer. If that person is found to have a harmful BRCA1 or BRCA2 mutation, then other family members can be tested to see if they also have the mutation.

Regardless, women who have a relative with a harmful BRCA1 or BRCA2 mutation and women who appear to be at increased risk of breast and/or ovarian cancer because of their family history should consider genetic counseling to learn more about their potential risks and about BRCA1 and BRCA2 genetic tests.

The likelihood of a harmful mutation in BRCA1 or BRCA2 is increased with certain familial patterns of cancer. These patterns include the following (15):

• For women who are not of Ashkenazi Jewish descent:
• two first-degree relatives (mother, daughter, or sister) diagnosed with breast cancer, one of whom was diagnosed at age 50 or younger;
• three or more first-degree or second-degree (grandmother or aunt) relatives diagnosed with breast cancer regardless of their age at diagnosis;
• a combination of first- and second-degree relatives diagnosed with breast cancer and ovarian cancer (one cancer type per person);
• a first-degree relative with cancer diagnosed in both breasts (bilateral breast cancer);
• a combination of two or more first- or second-degree relatives diagnosed with ovarian cancer regardless of age at diagnosis;
• a first- or second-degree relative diagnosed with both breast and ovarian cancer regardless of age at diagnosis; and
• breast cancer diagnosed in a male relative.
• For women of Ashkenazi Jewish descent:
• any first-degree relative diagnosed with breast or ovarian cancer; and
• two second-degree relatives on the same side of the family diagnosed with breast or ovarian cancer.

These family history patterns apply to about 2 percent of adult women in the general population. Women who have none of these family history patterns have a low probability of having a harmful BRCA1 or BRCA2 mutation.

7. How much does BRCA1 and BRCA2 mutation testing cost?

The cost for BRCA1 and BRCA2 mutation testing usually ranges from several hundred to several thousand dollars. Insurance policies vary with regard to whether or not the cost of testing is covered. People who are considering BRCA1 and BRCA2 mutation testing may want to find out about their insurance company’s policies regarding genetic tests.

8. What does a positive BRCA1 or BRCA2 test result mean?

A positive test result generally indicates that a person has inherited a known harmful mutation in BRCA1 or BRCA2 and, therefore, has an increased risk of developing certain cancers, as described above. However, a positive test result provides information only about a person’s risk of developing cancer. It cannot tell whether an individual will actually develop cancer or when. Not all women who inherit a harmful BRCA1 or BRCA2 mutation will develop breast or ovarian cancer.

A positive genetic test result may have important health and social implications for family members, including future generations. Unlike most other medical tests, genetic tests can reveal information not only about the person being tested but also about that person’s relatives. Both men and women who inherit harmful BRCA1 or BRCA2 mutations, whether they develop cancer themselves or not, may pass the mutations on to their sons and daughters. However, not all children of people who have a harmful mutation will inherit the mutation.

9. What does a negative BRCA1 or BRCA2 test result mean?

How a negative test result will be interpreted depends on whether or not someone in the tested person’s family is known to carry a harmful BRCA1 or BRCA2 mutation. If someone in the family has a known mutation, testing other family members for the same mutation can provide information about their cancer risk. If a person tests negative for a known mutation in his or her family, it is unlikely that they have an inherited susceptibility to cancer associated with BRCA1 or BRCA2. Such a test result is called a “true negative.” Having a true negative test result does not mean that a person will not develop cancer; it means that the person’s risk of cancer is probably the same as that of people in the general population.

In cases in which a family has a history of breast and/or ovarian cancer and no known mutation in BRCA1 or BRCA2 has been previously identified, a negative test result is not informative. It is not possible to tell whether an individual has a harmful BRCA1 or BRCA2 mutation that was not detected by testing (a “false negative”) or whether the result is a true negative. In addition, it is possible for people to have a mutation in a gene other than BRCA1 or BRCA2 that increases their cancer risk but is not detectable by the test(s) used.