Genetic testing involves looking for changes in a person’s genes, called mutations (or variants), that impact risk and could be found before any other signs of a disease. These mutations are inherited from a parent and carry different risks for cancer based on the specific mutation. Genetic testing can be performed by testing a person’s blood or saliva to identify whether they have inherited a genetic mutation in one of these genes.
There are many types of mutations that can be identified through genetic testing and are linked to hereditary cancer syndromes. Two of the most well-known genetic mutations in cancer are found in the BRCA1 and BRCA2 genes. Mutations found in these genes can lead to an increased risk of breast and ovarian cancers, or less commonly, of prostate and pancreatic cancers. There are additional gene mutations that increase risk for breast, colorectal or prostate cancers (see below for more info on genetic mutations and these cancer types).
Knowing your family health history is a good place to start. Use these tools to gather your family health history and discuss it with your health care provider.
NOTE: This information refers to predictive genetic testing only, which is different from tumor profiling (also known as genomic, biomarker or molecular profiling). Tumor profiling is done after a cancer diagnosis to determine mutations that may affect how the patient responds to certain treatments.
Where do I go for genetic testing?
If you are considering genetic testing, you should first meet with a genetic counselor or health care provider with expertise in cancer genetics. Genetic counseling is an important part of genetic testing due to the complexities involved. They will discuss the full picture of your health and risk factors (including family history), the pros and cons of genetic testing, implications of potential test results (including the psychological risks and benefits) and your options after you complete testing. If you have genetic mutations which put you at increased risk of cancer, talk with your health care provider about additional ways to reduce your risk, including medication and surgery.
You should check with your insurance company before meeting with a genetic counselor or health care provider to see if the meeting and/or genetic testing are covered by your insurance.
Why should I be tested?
You may want to think about genetic testing if:
There are several members of your family who have had the same type of cancer or you have one or more members of your family who have had multiple different types of cancer.
You have family members whose cancers were diagnosed at young ages for their cancer types.
There is cancer in your family that is sometimes linked to gene mutation (like breast or ovarian cancer), particularly if it has been diagnosed in several close relatives (parents, children or siblings).
Your family member has had genetic testing and discovered a gene mutation.
You are of Ashkenzi Jewish descent (1 in 40 will have a BRCA gene mutation).
Genetic testing—regardless of the result—does not take the place of routine cancer screenings. If you have a genetic mutation that increases your risk of developing cancer, you may need earlier or more frequent testing.
Broad-based genetic testing
Exercise caution when considering broad-based genetic testing, or simultaneously testing for hundreds of diseases. This type of testing is not individualized based on family history or personal risk, and may pick up mutations for which risk is not known or nothing can be done, which can result in more harm than good.
This is different from multigene panel testing, which is a type of genetic testing that is performed to look for mutations in several genes at one time. These panels may be recommended to you if you are at risk of a hereditary cancer syndrome that has more than one gene associated with it and are based upon your personal and family health history.
If you are adopted or estranged from your family
If you are adopted or estranged from your family, you might have limited or no knowledge of your family history. Talk to your genetic counselor or health care provider about any family health history you are aware of and your race/ethnicity to see if genetic testing makes sense for you. You should also always inform your health care provider if you are adopted.
Talking to your family
Gene mutations are hereditary and some of your relatives likely share similar or identical risk factors. Please discuss this topic with your family and help make them aware of their options, but understand if they make a different decision than you about genetic testing. It is a decision between each person and their health care providers and genetic counselors. Everyone has the right not to know about their genetic mutations.
Breast Cancer
Those assigned female at birth who test positive for BRCA1, BRCA2, PALB2 or several other gene mutations are at increased risk for breast or ovarian cancer. Those assigned male at birth who have BRCA2 mutations have an increased risk of breast cancer, and the same is true to a lesser degree for BRCA1 mutations. (Those assigned male at birth with BRCA1 or BRCA2 mutations are also at increased risk for prostate and pancreatic cancers.) BRCA mutations occur in all races and ethnicities, but one in 40 people of Ashkenazi Jewish descent has a mutation in the BRCA gene.
Colorectal Cancer
Those with a personal or family history of colorectal cancer or colon polyps, or a family history of Lynch syndrome (also called hereditary non-polyposis colorectal cancer) or familial adenomatous polyposis (FAP), are at increased risk for colorectal cancer. Genetic mutations associated with Lynch syndrome include MLH1, MSH2, MSH6, PMS2, EPCAM and those associated with FAP include APC.
Prostate Cancer
Those who were assigned male at birth who test positive for BRCA1, BRCA2, HOXB13 or several other gene mutations are at increased risk for prostate cancer. (Those who were assigned male at birth with BRCA1 or BRCA2 mutations are also at increased risk for breast and pancreatic cancers.) BRCA mutations occur in all races and ethnicities, but one in 40 of those of Ashkenazi Jewish descent has a mutation in the BRCA gene.
Genetic testing resources
Check out these resources to learn more about genetic testing, find answers to more frequently asked questions, and find a genetic counselor near you.
