Breast cancer affects approximately one out of every eight women over a lifetime, but some women are more vulnerable than others. The majority of women do not develop breast cancer due to a gene mutation, but between 5 and 10 percent of breast cancer patients do have a mutation of either the BRCA 1 or BRCA 2 genes. Women with BRCA mutations tend toward earlier cancer development than those in the general population. That is why BRCA testing for breast cancer is imperative.
According to the National Cancer Institute, roughly 70 percent of women with these gene mutations will go on to develop breast cancer. BRCA mutations also greatly increase the likelihood of ovarian cancer. Just 1.3 percent of women eventually are diagnosed with ovarian cancer, but if the BRCA mutation is present, as many as 44 percent of those affected will suffer from ovarian cancer.
BRCA 1 and BRCA 2 Genes
The function of the BRCA 1 and BRCA 2 genes is tumor suppression. These genes produce proteins that repair damaged DNA, but a mutation can mean that such damage goes unrepaired.
BRCA testing involves the doctor taking a saliva or blood sample from the patient and sending it off to a laboratory for analysis. Expect to receive the test results in about one month. If the tests are positive, meet with a genetic counselor to discuss the results and your options. Keep in mind that if the BRCA tests are negative, that does not mean you will not develop cancer, but that your risks are likely the same as the general population.
BRCA tests are not standard tests for most women. However, if you have a history of breast or ovarian cancer in your family, or have been diagnosed with these diseases, these tests will reveal whether you have a genetic predisposition toward these types of cancers.
Risk factors for a BRCA mutation include:
- Ashkenazi Jewish ancestry
- Breast cancer diagnosis before age 45
- Cancer in both breasts
- Family history
The BRCA mutations also affect men, increasing the risk of prostate and pancreatic cancer. A history of these diseases in close male relatives may indicate BRCA mutations.
Prophylactic Mastectomy or Oophorectomy
For those whose BRCA tests come back as positive, you have options going forward. While a positive result does not mean a woman is guaranteed to develop breast or ovarian cancer, it does mean the odds increase significantly. A positive result also means the woman may pass the mutation to her offspring, and that any full siblings have a 50 percent chance of sharing the mutation.
Women with no sign of the disease may opt for prophylactic mastectomy – surgical removal of the breasts –or oophorectomy, removal of the ovaries. The latter is generally a minimally invasive procedure performed via laparoscopy. If a woman chooses mastectomy, she may have a breast reconstruction procedure started at the same time.
Although both procedures contain risks, prophylactic mastectomy may reduce breast cancer development by 90 percent, with oophorectomy reducing ovarian cancer development by approximately the same amount.