BRCA1 and BRCA2 are genes found in the human body and are responsible for producing what are called tumor suppressor proteins, who’s function is to repair damaged DNA found in the body. Some people have mutations, or abnormalities in these genes which cause a malfunction in the BRCA gene's ability to function, allowing the DNA to go unrepaired, and placing them at a higher risk for developing certain types of cancers. BRCA1 and BRCA2 mutations are not gender specific and can affect both men and women. A genetic counselor can discuss with you your individual risks and recommend certain methods of genetic testing. They will also be able to discuss with you the results of your testing and your individual risks of developing a cancer.
For women, the risk of hereditary breast and/or ovarian cancer is significantly increased when there is a mutation in one or both of these genes. Women in the general population, or those without a mutation in the BRCA gene, have a 12% lifetime risk of developing breast cancer whereas those with an inherited BRCA1 mutation have a 55-65% percent risk of developing breast cancer by the age of 70 and those with a BRCA2 mutation have a 45% risk of developing breast cancer by the same age. When it comes to ovarian cancer, those with an inherited BRCA1 mutation have a 39% risk of developing ovarian cancer by age 70. For those women with a BRCA2 mutation, they have an 11-17% risk of developing the disease by the same age. Additional risk factors that may change the risk percentages for certain women with BRCA mutations include family history of breast/ovarian and other cancer history, her particular mutation and reproductive history.
In addition to female breast and ovarian cancers, BRCA1 and BRCA2 mutations increase both male and female risk of developing other forms of cancers such as fallopian tube cancers and peritoneal cancer in women, male breast cancer (especially in BRCA2 mutations), prostate cancer in men with BRCA1 or BRCA2 mutations and male and female pancreatic cancer in those with BRCA1 and BRCA2 mutations.
There are certain populations of people who have a higher risk of having a mutation in one of the BRCA genes, especially those who are of Ashkenazi Jewish descent. They however are not the only ones at risk; being of Norwegian, Dutch and Icelandic descent places a person at a higher risk of having a BRCA 1 and BRCA 2 mutation as well. Currently, there is limited data discussing the frequency of BRCA mutations in those of other ethnicities found in the United States, such as African Americans, Hispanics, Asian Americans and non-Hispanic whites.
The question of who should be tested for a BRCA1 and/or BRCA2 mutation is complicated which is why the expertise of a genetic counselor or healthcare provider experienced in genetics is extremely important. In men and women who themselves do not have cancer, testing should be performed when their individual family history is suggestive of a BRCA1 or BRCA2 mutation. Family histories which may indicate a mutation in BRCA1 and/or BRCA2 genes include:
- The presence of breast cancer prior to 50 years old
- Bilateral breast cancer (both breasts) and/or multiple family members with breast cancer
- The presence of both breast and ovarian cancer
- The presence of one family member with two or more primary types of BRCA1 or BRCA 2 cancers
- Any case of male breast cancer
- Those who are of Ashkenazi Jewish descent
There are screening methods and preventative measures which can be taken for those diagnosed with a BRCA mutation and include screening, surgery and chemoprevention. Discuss individual recommendations with your healthcare provider.
Some examples of screening methods include:
- Breast exams and mammogram starting between 25-35 years old for women with a known BRCA mutation. Some organizations also recommend an MRI in conjunction with a mammogram.
- Ovarian cancer screening including a transvaginal ultrasound, evaluation of CA-125 levels and physical exam. Despite this effort, effective ovarian cancer screening methods are lacking and unfortunately, even with this testing, these methods do not appear to detect ovarian cancers in the earliest stages.
- Men with BRCA mutations may be recommended to undergo mammograms and prostate cancer screening, despite the unknown benefits of screening this population.
In certain situations, surgery to reduce the risk of cancer development may be recommended although there is no guarantee that you will never develop cancer after undergoing a risk reducing surgery. Examples of risk reducing surgeries include, bilateral mastectomy and/or removal of both ovaries and fallopian tubes in women. For men, risk reducing mastectomy is considered an experimental procedure at this time. Another risk reducing method is chemoprevention which is the use of certain medications to prevent cancer or delay cancer recurrence.
- BRCA1 and BRCA2: Cancer Risks and Genetic Testing. Accessed February 21,2015.