BRCA Gene Testing

Medical City Plano offers BRCA gene testing through its Genetic Testing Program.

What is the BRCA gene?

Like the other genes in the cells that make up the human body, it is a piece of DNA that forms part of the code which determines what kind of organisms we are. In this respect, it is much like the code in which computer programs are written. If the code contains an error, the program will not work as it should.

In 1994, medical investigators identified the first BRCA gene, which they named BRCA1. A second such gene, BRCA2, was discovered in 1996.

Properly functioning BRCA genes help keep cancer cells from forming. A break or mutation in the genetic material allows cancer to form more easily and at an earlier age.

BRCA gene abnormalities account for 7-10 percent of all breast cancer cases. Another 15 percent are “familial” – meaning there is an inherited pattern of cancer although no BRCA mutation can be found. The remaining 75 percent are categorized as “sporadic,” which means that their cause is not fully understood.

Who is a candidate for breast cancer genetic testing?

Several factors in a person’s family history make her or him a candidate for genetic testing:

  • Breast cancer diagnosis before the age of 50.
  • A family history of ovarian cancer at any age.
  • A male family member with breast cancer.
  • A family member with breast cancer in both breasts (at the same time or at two separate times).
  • A family member with breast and ovarian cancer.
  • Ashkenazi or Eastern European Jewish ancestry.

What does a BRCA test involve?

A blood test is all that is required to analyze DNA for possible genetic abnormalities. A single tube of blood is sent to a laboratory that specializes in this kind of testing. A complex series of tests are performed, and the results are checked and rechecked over a two- to three-week period before the information is returned to the physician's office.

Both state and federal law prohibit the sharing of these test results with anyone – including health insurers – without a patient’s explicit authorization. The information cannot be used as a basis for increasing health insurance premiums or canceling coverage.

The information is valuable because BRCA1 mutations are associated with an 85 percent chance of developing breast cancer and a 45 percent chance of developing ovarian cancer. For BRCA2 mutations, the probabilities are 65 percent and 26 percent. Developing breast cancer a second time after surviving a first cancer can occur in up to 65 percent of patients with BRCA abnormalities. BRCA-positive males have a slightly elevated risk of breast cancer (6 percent greater than the general male population), and also an increased risk of developing prostate cancer at an earlier age.

The information has great bearing on the planning of surgery and the course of post-operative treatment. Instead of a lumpectomy, a woman with a BRCA gene mutation would be counseled to undergo a bilateral or double mastectomy due to the high risk of a second breast cancer. Surgery to remove the ovaries might also be considered to lessen the risk of ovarian cancer. Removing the ovaries reduces by half the chance of developing breast cancer.

For more information about Genetic Testing, or to make an appointment, please call (214)473-7402.