Genetic Cancer Testing

Submitted on March 27, 2012

Genetic Test for Breast Cancer

Genetic cancer testing is a test to determine if certain substances in the blood cells causing disease have passed on from one generation to another.  Every cell within a body has genes that instruct cells on growing and behaving. These genes contain DNA that passes on from generation to generation. A genetic test is usually conducted through a blood test to look for any kind of change in genes. Since this test has been widely used for determining breast cancer, it is also referred to as breast cancer genetic testing. Among the known genes, BRCA1 and BRCA2 are the most common genes in the development of hereditary breast cancer. Therefore, a breast cancer genetic test is carried out to determine if these genes have been passed on by the previous generation. These tests are done at specialized laboratories and hence are very expensive.


A genetic test for breast cancer is usually done to determine if the BRCA1 and BRCA2 mutations are found in the blood cells of certain individuals. Since these genes can only be passed on from previous generations, carrying this test is important to identify if the specific individual is likely to get cancer.


A letter from the doctor is needed to determine the potential impact of a positive result. Since the whole process of genetic testing for breast cancer is expensive, there are health insurances that can cover up to 80% of the cost. It is recommended to hire a counselor for pre-test as well as post-test counseling as in some cases a positive result may have emotional effects on patients.

Testing Procedure

The process involves taking of a sample of blood from the patient and sending it for testing. This is generally a very time consuming procedure. It is recommended that a blood sample of another family member who already has the cancer also be sent to the lab. There are three results that can be obtained from these tests, first, a positive result which means that the genetic mutation exists in the blood. Second, a true negative test which means that the genetic mutation has not been diagnosed. Finally, a result of indeterminate significance which means that a genetic change was found however, the doctors aren’t sure of what the change means. If the test is positive the test may be offered to other family members who have no signs of cancer yet.