About 5% to 10% of all cancers are thought to be related to gene mutations that are inheritedor passed down through the family. Having an inherited genetic mutation does not mean you will get cancer. It means you are at a higher risk for developing a certain type or types of cancer.
Medical tests can look for many inherited gene mutations. This type of testing is called predictive genetic testing. Most people do not need this type of genetic testing. It’s usually recommended when certain types of cancer run in a family and a gene mutation is suspected.
You might consider this type of testing if:
- You have several first-degree relatives (mother, father, sisters, brothers, children) with cancer.
- Many relatives on one side of your family have had the same type of cancer.
- A cluster of cancers in your family are known to be linked to a single gene mutation (such as breast, ovarian, colorectal, and pancreatic cancers in your family).
- A family member has more than 1 type of cancer.
- Family members have had cancer at a younger age than normal for that type of cancer.
- Close relatives have cancers that are linked to hereditary cancer syndromes.
- A family member has a rare cancer, such as breast cancer in a man or retinoblastoma (a type of eye cancer).
- Ethnicity (for example, Ashkenazi Jewish ancestry is linked to ovarian and breast cancers).
- A physical finding is linked to an inherited cancer (such as having many colon polyps).
- One or more family members have already had genetic testing that found a mutation.
If cancer runs in your family and you have a reason to think you might benefit from testing, talk with your health care provider and plan to meet with a genetic counselor. Genetic counselors have special training and often graduate degrees in their field. Some doctors, advanced practice oncology nurses, social workers, and psychologists with special training may also do genetic counseling.
Your health care provider can probably refer you to a genetic counselor in your area. If not, you can find a list of certified genetic counselors on the websites of the National Society of Genetic Counselors or the National Cancer Institute.
A genetic counselor can help you figure out whether testing is right for you and your family. And if you decide to get tested, a genetic counselor can help you interpret the results. Genetic testing results often give limited answers about having increased risk for certain cancers. They can’t tell you whether you will or will not get cancer. This is one reason why counseling is so important.
Some genetic test manufacturers advertise and promote their tests to doctors and to the public. Sometimes they can make the test sound much more helpful and decisive than it’s actually proven to be. This can be harmful because decisions about testing may be made based on incomplete information, or even on misleading or wrong information. A genetic counselor can steer you to a reputable lab and help you know what to expect from your test results.
More to consider
Other family members: Genetic testing results affect not just you; they also affect family members who share your genes. Not everyone might want to know if they are at increased risk. Learning that you or a family member might have an increased cancer risk can be upsetting. The possibility of having a certain genetic mutation or passing the faulty gene on to children can also lead to feelings of guilt or anger.
Tests can lead to more tests: In some cases, more medical tests, cancer screenings, or procedures may have to be done as a result of genetic testing. This can be a good thing, if these other tests help keep you free of cancer or if they find it early, when it’s likely to be easier to treat. But the tests can have downsides as well, such as the time and expense involved, as well as possible risks from the tests themselves. These extra tests can also lead to more stress and anxiety.
Cost: Genetic testing can be expensive. Some tests cost more than others, and the final bill can be thousands of dollars. Be sure you have an idea of how much it will cost you before you have testing done.
Insurance questions: If you have health insurance, you’ll need to decide if you’re going to ask your insurance company to help pay for testing. For the most part, state and federal laws do not require insurance companies to pay for predictive testing, so not all of them cover or help pay for the tests.
Federal health care laws say that genetic testing should be covered for some women found to be at higher risk for breast and/or ovarian cancer. The amount of coverage depends on your health plan, so you have to contact them to find out what’s covered.
Privacy: Some Americans fear that employers and insurance companies might find out about a genetic mutation and use it against them. Discrimination and employment decisions based on genetic information are barred at the national level for most employers. Even so, some people choose to pay for genetic testing themselves in order to keep the results as private as possible.
Employers should not request genetic testing for inherited genetic mutations. They are only allowed to ask for a worker to have genetic testing if there is a possibility of exposure to potentially toxic chemicals and substances in the workplace, which may lead to a different kind of gene mutation.
The Genetic Information Nondiscrimination Act of 2008 is a federal law that prohibits the use of genetic information in workplace employment decisions for non-governmental organizations with more than 15 employees. This law also bars health insurers from making coverage or cost decisions based on genetic information. But the law does not restrict use of genetic information for life insurance, disability insurance, or long-term care insurance.
In addition, medical and pharmaceutical researchers may be interested in having genetic information and samples to assist with development of medications to treat some diseases. These researchers are required to get the individual’s informed consent and explain what will be done before obtaining genetic tissue samples and doing any studies on them.