Genetic Testing: What You Need to Know

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Who should have genetic testing?

Genetic testing to learn about your cancer risk is done only if you decide to have it. If you are concerned about your family’s pattern of disease, cancer you’ve had in the past, or other cancer risk factors, you may want to talk to your doctor about whether to have genetic testing.

Doctors will sometimes suggest patients have genetic testing if others in their family have had a certain disease or certain patterns of disease. If you have any of the following, you might consider genetic testing for yourself:

  • Several first-degree relatives (mother, father, sisters, brothers, children) with cancer, especially if they’ve had the same type of cancer
  • Cancers in your family that are sometimes linked to a single gene mutation (for instance, breast, ovarian, and pancreatic cancer).
  • Family members who had cancer at a younger age than normal for that type of cancer
  • Close relatives with rare cancers that are linked to inherited cancer syndromes
  • A physical finding that is linked to an inherited cancer (such as having many colon polyps)
  • A known genetic mutation in one or more family members who have already had genetic testing

You need to know what tests may be available. For some types of cancer, no known mutations have been linked to an increased risk. Other cancer types may have known mutations, but genetic tests are not yet available for them. For more information on the types of cancers for which inherited genes may be important, please see our document Family Cancer Syndromes.

It’s important to find out how useful testing may be for you before you do it. Meeting with a genetic counselor before the actual test can help you know what to expect. The counselor can tell you about the pros and cons of the test, what the results might mean, and what your options would be at that point. You will want to think about how the results might affect you and your relatives, and discuss these issues with the counselor before your test.

After the test is done, your genetic counselor will share the results with you. Some people choose to bring a family member to help share results with other family members. Although testing does not always give you clear answers, genetic counselors are trained to interpret and explain the test results and what they might mean to you and your family. If a mutation is found, the counselor will talk to you about which of your family members might also be affected. It will be important for those family members to know exactly which mutation was found and in which gene. They can then discuss this information with their doctors and consider being tested, too.

Last Medical Review: 10/18/2013
Last Revised: 03/11/2015