When it comes to inherited cancer risk, BRCA1 and BRCA2 are two of the best-known genes. But each of these two genes can affect cancer risk in slightly different ways.
“People who inherit harmful changes in the BRCA1 or BRCA2 gene have a greater likelihood of developing cancer in their lifetime, and a greater risk of developing cancer at a younger age,” explains Carmen Stokes, Ph.D., a cancer nurse navigator at Henry Ford Health. These genes increase breast cancer risk, as well as the risk of several other cancers in both women and men.
Dr. Stokes explains what to know about BRCA1 and BRCA2, and what a positive BRCA test result means for your health.
What Are BRCA Genes?
Everyone has BRCA1 and BRCA2 genes, inherited from their parents. In some people, those genes have harmful changes that affect their function. People with those changes have a higher risk of developing cancer. Initially, researchers discovered that women who inherited certain versions of these genes were at high risk for developing breast cancer.
The name “BRCA” is short for “breast cancer gene,” Dr. Stokes explains. “But since then, the genes have been linked to other types of cancer,” she adds.
Each BRCA gene affects risk in different ways.
High Risk Breast Cancer Clinic at Henry Ford Health
Breast cancer
- More than 60% of women with harmful changes in either the BRCA1 or BRCA2 gene will develop breast cancer, compared to 13% of women in the general population.
- About 0.2% to 1.2% of men with BRCA1 changes will develop breast cancer, compared to 0.1% of men in the general population.
- About 1.8% to 7.1% of men with BRCA2 changes will develop breast cancer.
Ovarian cancer
- An estimated 39% to 58% of women with a positive BRCA1 test will develop ovarian cancer in their lifetimes, compared to 1.1% of women in the general population.
- About 13% to 29% of women positive for BRCA2 will develop ovarian cancer.
Prostate cancer
- Up to 26% of men with a positive BRCA1 test will develop prostate cancer, compared to 10.6% of men in the general population.
- Between 19% and 61% of men with a positive BRCA2 test will develop prostate cancer.
Pancreatic cancer
- About 5% of people with harmful BRCA1 changes will develop pancreatic cancer, compared to 1.7% of the general population.
- Between 5% and 10% of people with changes to BRCA2 will develop pancreatic cancer.
“There is also evidence that BRCA1 and BRCA2 could increase the risk of stomach cancer and melanoma, but researchers are still exploring those connections,” Dr. Stokes says.
Unfortunately, it’s also possible to inherit changes on both the BRCA1 and BRCA2 gene. Having both genes affected may further increase your risk of developing cancer.
What to Do if You Test Positive for BRCA
Getting a positive test for BRCA1 and BRCA2 can be scary. “But it’s important to remember that being positive for BRCA1 or BRCA2 doesn’t mean you will definitely get cancer,” Dr. Stokes says. “And having this information can help guide you toward health or lifestyle choices that reduce your risk.”
Those choices include:
- Surgical prevention: After consulting with a medical provider, some women with a high lifetime risk of breast cancer may choose to have a preventive mastectomy (having their breasts removed), for example. Women might also consider having their ovaries and fallopian tubes removed to prevent ovarian cancer, especially if they don’t plan to have children in the future.
- Medical prevention: In some cases, doctors may prescribe medicines to reduce the risk of breast cancer.
- Screening: If you’ve had a positive BRCA test, your doctor may screen you more often for cancer or recommend different screening tools. In addition to regular screening mammograms, for example, BRCA-positive patients might also undergo MRI breast screenings. In BRCA-positive men, doctors may recommend using ultrasound screening to check for prostate cancer in addition to the standard PSA prostate screening blood test.
- Lifestyle changes: Healthy lifestyle choices—eating a healthy diet, engaging in regular exercise, getting plenty of sleep—can help reduce cancer risk in anyone, regardless of whether they inherited a harmful change to one of the BRCA genes. “But these types of choices can be especially important in people at increased risk of cancer,” Dr. Stokes says.
If you’ve tested positive for BRCA1 or BRCA2, you and your doctor can work together to decide which options make sense for you—and when the time is right to consider options like surgery.
Who Should Get BRCA Testing?
BRCA tests can provide helpful information about your cancer risk. But testing isn’t recommended for everyone. Medical guidelines recommend considering BRCA testing if you have risk factors such as:
- A diagnosis of breast cancer before age 50
- A personal or family history of breast, ovarian, pancreatic or high-risk prostate cancer
- A family member who tested positive for harmful BRCA1 or BRCA2 variants
- Ashkenazi Jewish heritage
Genetic counselors can help consider your risk factors, recommend appropriate genetic tests and help you weigh the pros and cons of getting tested. “Some people think it’s better not to know, but having this information can help you take steps to reduce your cancer risk,” Dr. Stokes says.
Reviewed by Carmen Stokes, Ph.D., an oncology nurse navigator at Henry Ford Providence Novi Hospital.
