15/06/2026
What is genetic testing?
Genetic testing is a type of medical test that looks for certain gene changes (mutations) in a person. Many types of genetic tests exist for many purposes and more are being developed. Here, we focus on how they are used to understand cancer and cancer risk.
For cancer risk
Genetic testing can help inform the likelihood that someone will get cancer at some point in their life.
While this information can be helpful for some people, it cannot say for certain if you will or won’t get cancer. Cancer risk depends on many factors and can also change over time due to lifestyle choices, exposure to cancer-causing agents, and aging.
Biomarker tests vs. genetic testing
If you have been diagnosed with cancer, your cancer care team might order biomarker tests to look for certain gene or protein changes in cancer cells to help plan treatment or give information on your outlook (prognosis).
These types of tests look for gene changes only in the cancer cells. These tests are not the same as the tests used to find out about inherited cancer risk.
Who might benefit from genetic testing
While most people do not need genetic testing, it might be suggested for several reasons.
Having a strong family history of certain types of cancer
Based on your family history and what kinds of genetic tests are available, genetic testing might be done to see if you have an inherited gene change. For some types of cancer, no known gene changes have been linked to an increased risk.
If you have an inherited gene change, you might be recommended to start getting screened for cancer at a younger age or more often. You also might want to take steps to try to lower your risk. Your family members might also consider getting genetic testing.
Consider talking to your primary care team about seeing a genetic counselor about genetic testing if you have:
Multiple relatives with certain cancers
Several first-degree relatives (mother, father, sisters, brothers, children) with the same type of cancer
Many relatives on 1 side of the family who have had the same type of cancer
A cluster of cancers in your family that are known to be linked to a single gene change such as breast, ovarian, and pancreatic cancers, which are sometimes linked to BRCA gene changes
Rare cancer features in you or a family member
A family member with more than 1 type of cancer
Family members who had cancer at a younger age than normal for that type of cancer
A family member who has cancer in both paired organs, such as both breasts or both kidneys
A rare cancer such as breast cancer in a man or retinoblastoma, in you or a family member
Close relatives with cancers that are linked to rare hereditary cancer syndromes
Other reasons
A physical finding that’s linked to an inherited cancer such as having many colon polyps
A known genetic change in 1 or more family members who have already had genetic testing
Lab tests of your cancer cells that show features that might be linked to an inherited gene change
A particular race or ethnicity such as Ashkenazi Jewish ancestry, which is linked to a higher risk of BRCA gene changes
Learn more about the types of cancer that might be linked to inherited genes.
After certain cancer diagnoses
Genetic testing might be done after a cancer diagnosis if there are reasons to think your cancer might have been caused by an inherited gene change, such as:
A strong family history of the cancer
If you were diagnosed with a cancer at a young age
If the cancer is uncommon
It might show if you have a higher risk of developing some other cancers. It can also help other family members decide if they want to be tested
INFORMATION TAKEN FROM THE AMERICAN CANCER SOCIETY :
https://www.cancer.org/cancer/risk-prevention/genetics/genetic-testing-for-cancer-risk.html
