A tumor marker is a substance found in your blood, urine, or body tissue. The term “tumor markers” may refer to proteins that are made by both healthy cells and cancer cells in the body. It may also refer to mutations, changes, or patterns in a tumor’s DNA. Tumor markers are also called biomarkers.
These tests look for tumor markers, sometimes called cancer markers, in the blood, urine, or body tissues. Tumor markers are substances made by cancer cells or by normal cells in response to cancer in the body. Some tumor markers are specific to one type of cancer.