Approximately 10 percent of patients with breast cancer have a genetic variant that increased their risk of developing the disease. An additional 20 percent have a close family member who also had breast cancer, suggesting a familial link even though no specific genetic variant was identified.
BRCA1 and BRCA2 are the most common genes known to increase the risk of breast and ovarian cancers. Variations in these genes can also increase the risk for other cancers, including fallopian tube cancer, primary peritoneal cancer, pancreatic cancer, melanoma, male breast cancer, and prostate cancer.
A genetic variation in BRCA1 or BRCA2 can increase the likelihood that a person will develop cancer in his or her lifetime.
|Breast cancer||Ovarian, fallopian tube & peritoneal cancer||Pancreatic cancer||Prostate cancer||Melanoma|
|BRCA1||♀: 40-87%||♀: 16-44%|
|BRCA2||♀: 40-85% ♂: 7-8%||♀: 16-27%||♀: 2% ♂: 3%||♂: 20%||♀: Elevated ♂: Elevated|
Many other genes can increase an individual’s risk of developing breast cancer, including CDH1, PALB2, PTEN, STK11, and TP53. Like BRCA1 and BRCA2, many of these genes also influence risk for other types of cancers.
Genetic testing may be appropriate if you have:
Knowledge of your inherited risk for cancer can be a useful tool to guide prevention and risk-reduction. If you have an elevated risk of developing cancer based on your genetic test result, you can work with your healthcare provider to create a plan designed to prevent a cancer entirely, or help to identify a cancer at its earliest, most treatable stage.
In addition, genetic testing produces information that may help you and your healthcare provider:
Identifying at-risk family members is one of the most important benefits of genetic testing. Screening family members for known familial genetic variants gives those who test positive the opportunity to make informed decisions on prevention strategies. For those who test negative, the results can bring peace of mind. Invitae offers a Family Variant Testing program; please inquire with your doctor.
Your physician will assist you in identifying and arranging for the appropriate genetic test(s). If you have specific questions or concerns about the testing, your physician may refer you to a genetic counselor to discuss further. Once you are ready to proceed with genetic testing, you will need to submit either a blood or saliva sample.