Three of the most well-known genes that can mutate and raise the risk of breast and/or ovarian cancer are BRCA1, BRCA2, and PALB2. Women who inherit a mutation, or abnormal change, in any of these genes — from their mothers or their fathers — have a much higher-than-average risk of developing breast cancer and/or ovarian cancer. (Abnormal PALB2 genes are suspected to raise the risk of ovarian cancer, but larger studies need to confirm that risk.) Men with these mutations have an increased risk of breast cancer, especially if the BRCA2 gene is affected, and possibly of prostate cancer. Many inherited cases of breast cancer have been associated with mutations in these three genes.
The function of the BRCA and PALB2 genes is to keep breast cells growing normally and prevent any cancer cell growth. But when these genes contain the mutations that are passed from generation to generation, they do not function normally and breast cancer risk increases. Abnormal BRCA1, BRCA2, and PALB2 genes may account for up to 10% of all breast cancers, or 1 out of every 10 cases.
Most people who develop breast cancer have no family history of the disease. However, when a strong family history of breast and/or ovarian cancer is present, there may be reason to believe that a person has inherited an abnormal gene linked to higher breast cancer risk. Some people choose to undergo genetic testing to find out. A genetic test involves giving a blood or saliva sample that can be analyzed to pick up any abnormalities in these genes.
In this section, you can read more about the following topics related to genetic testing:
- Learning About Your Family Background
- Deciding Who in the Family Should Get Tested
- Consent for the Gene Test
- Seeking Your Genetic Information: Pros and Cons
- Genetic Testing Facilities and Cost
- Getting Genetic Test Results
- What to Do if Your Genetic Test Results Are Negative
- What to Do if Your Genetic Test Results Are Positive
- What to Do if Your Genetic Test Results Are Uncertain
- Preimplantation Genetic Diagnosis for BRCA Mutation Carriers
If you want to learn more about family-related risk and genetics, you can visit the Lower Your Risk section of this site.
Researchers have discovered, and are continuing to discover, other abnormal genes that are less common than BRCA1, BRCA2, and PALB2 but also can raise breast cancer risk. Testing for these abnormalities is not done routinely, but it may be considered on the basis of your family history and personal situation. You can work with your doctor to decide whether testing for gene abnormalities besides BRCA1, BRCA2, and PALB2 is warranted.
To connect with others who have tested positive for a gene abnormality that raises risk, visit the Breastcancer.org Discussion Board forum Positive Genetic Test Results.
The medical experts for Genetic Testing are:
- Cristina Nixon, M.S., L.C.G.C., genetic counselor, Main Line Health, suburbs of Philadelphia, PA
- Rachael Brandt, Ph.D., L.C.G.C., genetic counselor, Main Line Health suburbs of Philadelphia, PA
- Generosa Grana, M.D., F.A.C.P., breast cancer genetics specialist, Cooper Hospital/University Medical Center, Camden, NJ
- Marisa Weiss, M.D., chief medical officer of Breastcancer.org; breast radiation oncologist, Lankenau Medical Center, part of Main Line Health, a five-hospital health system in the suburbs of Philadelphia, PA
These experts are members of the Breastcancer.org Professional Advisory Board, which includes more than 70 medical experts in breast cancer-related fields.
"Simply having a proven gene abnormality does not necessarily mean that a woman will develop breast cancer, or that her cancer will be any worse than cancer that does not stem from an inherited genetic flaw."-- Marisa Weiss, M.D., chief medical officer, Breastcancer.org