BRCA1 and BRCA2 are genes that help prevent tumors from growing.
If you inherit a change, or mutation, in these genes, they stop doing their jobs, and cancer can develop.
In the United States, about 1 in every 400 people has a BRCA gene mutation. Both women and men can be affected. (1)
Most individuals acquire just one of these mutated genes, but some people can have both a BRCA1 and a BRCA2 alteration. (2)
If You Carry a BRCA1 or BRCA2 Mutation, What Cancers Are You At Risk For?
The BRCA genes are most often associated with breast cancer. In fact, BRCA1 is short for “breast cancer gene one,” and BRCA2 for “breast cancer gene two.”
Research shows that anywhere from 55 to 72 percent of women with BRCA1 genetic mutation and 45 to 69 percent of women with a BRCA2 genetic mutation will develop breast cancer. To put that in perspective, women in the general population have about a 12 percent chance of developing breast cancer at some point in their lives. (3)
The risk of developing ovarian cancer is also high for women with a BRCA1 or BRCA2 gene alteration. About 44 percent of women with a BRCA1 mutation and about 17 percent of those with a BRCA2 mutation will develop ovarian cancer by age 80. Only about 1.3 percent of women in the general population are likely to have ovarian cancer during their lives. (3)
In addition to breast and ovarian cancer, having a BRCA gene mutation can increase a woman’s risk of developing:
- Cervical cancer
- Uterine cancer
- Pancreatic cancer
- Colon cancer
- Stomach cancer
- Gallbladder or bile duct cancer
Men with a BRCA mutation may be more likely to have:
- Breast cancer
- Testicular cancer
- Pancreatic cancer
- Prostate cancer (4)
How Do BRCA1 and BRCA2 Increase Your Risk for Cancer?
Can You Be Tested for BRCA1 and BRCA2?
Yes, tests are available to identify BRCA mutations.
Genetic testing involves providing a sample of blood or saliva, so doctors can analyze it in a lab.
This test is only recommended for people at high risk, such as those who have or have had:
- Breast cancer before age 50
- Breast cancer in both breasts
- Breast and/or ovarian cancer
- One or more family members with breast cancer, ovarian cancer, pancreatic cancer, or prostate cancer
- A male relative with breast cancer
- A family member with a BRCA mutation
Additionally, people of Ashkenazi Jewish descent are more likely to have a mutation and may want to consider genetic testing. (7)
It’s a good idea to meet with a genetic counselor. This professional can help assess your family history, explain the pros and cons of testing, and help you interpret your results.
Why Is It Important to Know if You Are At Risk for BRCA1 and BRCA2?
If one of your family members has a BRCA defect, there’s a chance you could, too.
Men and women with a BRCA mutation have a fifty-fifty chance of passing it on to each of their children.
Identifying the mutation can help you better understand your cancer risk and that of your children and other descendants. (7)
History of the BRCA1 and BRCA2 Genes: When Were They Discovered?
After many years of study, a team of researchers officially discovered the BRCA1 gene in 1994. The BRCA2 gene was then identified in 1995. (8)
What Do You Do if You Test Positive for BRCA1 or BRCA2?
Finding out you have a BRCA mutation may be scary, but this information can also help you and your doctor plan prevention strategies.
If your result is positive, you’ll undergo earlier and more frequent diagnostic tests, such as mammograms, breast MRIs, ultrasounds, pelvic exams, and breast exams. Doctors will typically also screen for pancreatic cancer and screen more aggressively for prostate cancer in men who carry a BRCA mutation.
You may also choose to take a cancer-fighting drug, like tamoxifen (Soltamox), to reduce your risk of developing breast cancer. Or your doctor might recommend that you take birth control pills for a certain amount of time to lower your chances of ovarian cancer.
Some women choose to have preventive surgery, such as prophylactic breast removal (mastectomy) or ovary removal. A preventive mastectomy can reduce breast cancer risk in women with a BRCA mutation by as much as 90 percent. (7)
Your doctor can explain your options in detail.