Can a tumor test reveal an inherited gene change?

Yes. A tumor (biomarker) test looks mainly for changes that arose in the cancer during a person's life, but it can sometimes find a change that the person was actually born with.

According to the National Cancer Institute, when a tumor test uncovers a change that may be inherited, a separate germline test is usually recommended to confirm whether the change is truly inherited. This matters because an inherited change affects a person's future risk of other cancers and can carry information for their blood relatives.

If an inherited change that raises cancer risk is found, a health care provider may recommend speaking with a genetic counselor or other genetics professional to help make sense of what the result means for the person and their family. So a tumor test and an inherited-risk test can work together, even though they start with different goals.