Thinking about cancer or dealing with cancer risk can be scary or overwhelming, but we believe that receiving information and resources is comforting, empowering, and lifesaving.
Between 10% and 20% of many common cancers are considered "hereditary." Hereditary cancers are caused by gene mutations that people are born with; passed down to them from either their mother or their father.
Laboratory tests performed on blood, saliva or tumor tissue can analyze a person's genes to tell if they carry an inherited mutation in a gene that is associated with an increased risk for cancer. Genetic testing in people already diagnosed with cancer can also determine if their cancer was caused by an inherited mutation.
The two genes most commonly responsible for hereditary breast and ovarian cancer are named BRCA1 and BRCA2. Mutations in these genes can also increase the risk for other cancers, including male breast cancer, pancreatic cancer, prostate cancer, and melanoma.
The five genes most commonly responsible for hereditary colorectal and endometrial cancer are also known as Lynch Syndrome genes. Mutations in these genes can also increase the risk for ovarian, stomach, pancreatic and other cancers. Mutations in two of the Lynch Syndrome genes have also been linked to increased risk for breast cancer.
Other gene mutations have been discovered that increase the risk for these cancers including PALB2, CHEK2, ATM, BRIP1 and others. You can read more about these genes here.
There are many different types of genetic tests. Some tests look for one or a few specific gene mutations. Other tests—known as multigene panels—look for many gene mutations at the same time. The best test for you will depend on your exact situation.
Genetic testing can be complex:
For these reasons, it is important to speak with a specialist in cancer genetics—known as a genetic counselor—if you are concerned that cancer may run in your family or if you are interested in genetic testing.
Genetic test results can affect people's decisions about medical care. For people who have already been diagnosed with cancer, genetic test results may affect their treatment options. Genetic test results also affect the risk for a new diagnosis of cancer. People who test positive for a genetic mutation have medical options for lowering their cancer risk or detecting cancer early when it is most treatable.
Insurance will usually cover the cost of genetic testing. See our page on insurance coverage for more information.
In the United States, genetic results are usually available in 2-3 weeks. Under some circumstances—for individuals newly diagnosed with cancer, for whom test results may affect treatment choices—the test can be run more quickly.