About 10 percent of all cancer is inherited. Genetic testing is available to measure your cancer risk if you have a strong personal or family history of cancer. Every cell in the body contains genes, which are the body's blueprints determining things like eye color and height. Sometimes a person can have gene changes called mutations. These changes cause the genes to work wrong.
Genetic testing can:
- Search for gene mutations that help explain why you are more likely to get a disease than someone else
- Help your medical team make decisions about your care, such as cancer screenings or prevention options, if you are a carrier of a specific gene mutation
- Provide cancer risk information for other family members
Ideally, the first person in the family to have genetic testing would be someone who has been diagnosed with cancer. That way the information informs about the risk for developing a separate, unrelated cancer. It also provides the most information to family members about their cancer risk.
In some circumstances, the family member with cancer is not able to go through genetic testing. If this happens, genetic testing may be started with a different family member once you've discussed possible genetic testing results with a genetic counselor or genetics nurse through the Family Cancer Risk Service.
Who is an appropriate candidate for genetic testing for cancer risk?
You may wish to consider genetic testing if you or a family member meet any of the criteria listed below:
- Diagnosed with cancer before age 50
- Have three or more relatives on the same side of the family with the same cancer type
- Have one or more relatives with multiple cancers, such as breast and ovarian cancer
- Diagnosed with a rare or unusual cancer, such as male breast cancer or a sarcoma
The results of your genetic test may help to:
- Find gene changes responsible for an already diagnosed disease
- Find gene changes that increase the risk developing of cancer
- Find gene changes that could be passed on to children
- Find gene changes in other blood relations, such as brothers, sisters, aunts, uncles and cousins
- Guide cancer screening recommendations or provide options for cancer risk reduction
- Clarify that some patients or family members may not have a particular gene change and so may not be at increased risk of developing cancer
Genetic tests are done on a small sample of tissue from your body. These tissues may include:
The sample taken is collected by your health care provider and sent to a CLIA- approved laboratory that tests for certain changes in your DNA. The lab usually gives the test results in writing to your health care provider, who then discusses them with you.
If you are trying to decide whether or not to get genetic testing, some questions you may want to ask are:
- Are they any ways to prevent or treat the disease for which I’m being tested?
- Will my health insurance cover the cost of genetic test?
- Are there any laws to protect my genetic information from use by my health insurance company or my employer?
- How will the information gained from this testing impact my family members?
What are some cancers for which genetic testing is currently offered?
- Cancers of the endocrine system
More resources on genetic testing: