Genetic testing for breast cancer involves examining a sample of blood for evidence of certain genetic mutations which have been shown to increase an individual’s chance of developing breast and ovarian cancers. Generally, genetic testing for breast cancer is performed only on those who, based on personal or family history, have a heightened risk of developing these cancers. The testing process can be extremely emotional, and those undergoing testing usually must consult with a genetic counselor both before the test and after the results have become available.
In normal cells, two genes, known as BRCA1 and BRCA2, promote cell health by discouraging abnormal growth. Researchers have discovered that when the BRCA1 or BRCA2 genes mutate, they can lose the ability to keep abnormal cell growth in check. Individuals with BRCA1 or BRCA2 mutations face a higher risk of developing breast and ovarian cancers than the general public. As these mutations are hereditary, this risk can be passed from parent to child.
The aim of genetic testing for breast cancer is to determine whether an individual possesses a BRCA1 or BRCA2 mutation. Confirming or ruling out the presence of these mutations provides valuable information about one’s chances of developing cancer. If mutations are identified, the tested individual can develop a plan for minimizing her cancer risk as much as possible. Through testing, she can also learn whether she might pass on a BRCA1 or BRCA2 mutation to her children.
Going through the process of genetic testing for breast cancer can be very emotional. Positive results can lead to depression, anger, anxiety, and many other complications in both the tested individual and her loved ones. Even a negative result may not leave all tested individuals feeling totally reassured. Largely due to its emotionally difficult nature, the test is usually performed only on those who have a personal or family history of breast or ovarian cancers. Further, those undergoing the test must usually meet with a counselor prior to testing to discuss the potential ramifications of a positive or negative result.
During the testing process, a physician draws a blood sample from the subject’s arm. The sample is then sent to a genetic testing lab for analysis. It often takes several weeks or even months to receive results.
Once test results have become available, the tested individual usually must meet with her genetic counselor once again. At this time, the counselor will offer emotional support and help her interpret the personal meaning of the test results. If the test reveals a BRCA1 or BRCA2 mutation, the counselor will help the tested individual explore options such as having frequent cancer screenings, taking preventive medications, or having the breast tissue removed.