What is a tumor marker test used to determine?

A tumor marker test is specifically used to measure the levels of certain substances in the blood, urine, or tissues that may indicate the presence of cancer. These substances, known as tumor markers, are typically produced by cancer cells or by normal cells in response to cancer. By analyzing the concentration of these markers, healthcare providers can get valuable information that aids in diagnosing cancer, monitoring treatment response, and detecting recurrences of the disease.

Tumor markers are not designed to assess viral infections, evaluate kidney functionality, or identify possible birth defects, as those conditions require different diagnostic approaches and tests specifically suited for their respective evaluations. Therefore, the use of tumor markers is distinctly associated with cancer detection, making this answer the most accurate choice.