There are various genetic companies available through a Cancer Genetic Counselor, Primary Care Physician or OB/GYN that can perform the genetic test. Whether you choose preventative surgery or opt to undergo more frequent cancer screenings, you actually have a choice. You may NOT have signs or symptoms. The most important and powerful preventative measure you have is knowledge. Be aware of your family history. If a close relative has a history of either breast or ovarian cancer, talk to a Genetic Counselor. A simple blood or swab test can be done the same day in a Genetic Counselor's office. Then, you can decide on a plan of action that works best for you and your family.
BRCA1 and BRCA2 are human genes that produce tumor suppressor proteins. These proteins help repair damaged DNA and, therefore, play a role in ensuring the stability of the cell’s genetic material. When either of these genes is mutated, or altered, such that its protein product either is not made or does not function correctly, DNA damage may not be repaired properly. As a result, cells are more likely to develop additional genetic alterations that can lead to cancer.
Specific inherited mutations in BRCA1 and BRCA2 increase the risk of female breast andovarian cancers, and they have been associated with increased risks of several additional types of cancer. Together, BRCA1 and BRCA2 mutations account for about 20 to 25 percent of hereditary breast cancers and about 5 to 10 percent of all breast cancers. In addition, mutations in BRCA1 and BRCA2 account for around 15 percent of ovarian cancers overall. Breast and ovarian cancers associated with BRCA1 and BRCA2 mutations tend to develop at younger ages than their nonhereditary counterparts.
A harmful BRCA1 or BRCA2 mutation can be inherited from a person’s mother or father. Each child of a parent who carries a mutation in one of these genes has a 50 percent chance (or 1 chance in 2) of inheriting the mutation. The effects of mutations in BRCA1 andBRCA2 are seen even when a person’s second copy of the gene is normal.
A woman’s lifetime risk of developing breast and/or ovarian cancer is greatly increased if she inherits a harmful mutation in BRCA1 or BRCA2.
Breast cancer: About 12 percent of women in the general population will develop breast cancer sometime during their lives. By contrast, according to the most recent estimates, 55 to 65 percent of women who inherit a harmful BRCA1 mutation and around 45 percent of women who inherit a harmful BRCA2 mutation will develop breast cancer by age 70 years.
Ovarian cancer: About 1.3 percent of women in the general population will develop ovarian cancer sometime during their lives. By contrast, according to the most recent estimates, 39 percent of women who inherit a harmful BRCA1 mutation and 11 to 17 percent of women who inherit a harmful BRCA2 mutation will develop ovarian cancer by age 70 years .
It is important to note that these estimated percentages of lifetime risk are different from those available previously; the estimates have changed as more information has become available, and they may change again with additional research. No long-term generalpopulation studies have directly compared cancer risk in women who have and do not have a harmful BRCA1 or BRCA2 mutation.
It is also important to note that other characteristics of a particular woman can make her cancer risk higher or lower than the average risks. These characteristics include her family history of breast, ovarian, and, possibly, other cancers; the specific mutation(s) she has inherited; and other risk factors, such as her reproductive history. However, at this time, based on current data, none of these other factors seems to be as strong as the effect of carrying a harmful BRCA1 or BRCA2 mutation.
Yes. Several different tests are available, including tests that look for a known mutation in one of the genes (i.e., a mutation that has already been identified in another family member) and tests that check for all possible mutations in both genes. DNA (from a bloodor saliva sample) is needed for mutation testing. The sample is sent to a laboratory for analysis. It usually takes about a month to get the test results.