Tumor markers are used for which purpose?

• A. Screening for cancer and monitoring treatment effectiveness
• B. Diagnosing bacterial infections
• C. Measuring bone density
• D. Assessing kidney function

Answer: (A)

Tumor markers help assess cancer activity and track response to treatment. They are substances, often proteins, produced by cancer cells or by the body in response to cancer, and they’re used to screen for certain cancers in some contexts and to monitor how well therapy is working or whether the disease is recurring. They are not definitive tests for diagnosing cancer on their own, and results must be interpreted with imaging and clinical information because false positives and false negatives can occur. They aren’t used to diagnose bacterial infections, measure bone density, or assess kidney function, which rely on different tests and markers.