Cancer marker

A cancer marker is a substance, often a protein, found in the blood, urine, or tissues, that can indicate the presence of cancer. These markers are produced or released by cancer cells or normal cells in response to cancer. Measuring their levels helps doctors detect, diagnose, and monitor the progress of certain types of cancer. However, elevated markers can sometimes be caused by benign conditions too, so they are used alongside other tests to provide a comprehensive assessment. Overall, cancer markers are valuable tools but not definitive on their own for diagnosing cancer.