What is the purpose of tumor markers in oncology?

The purpose of tumor markers in oncology primarily revolves around monitoring treatment responses and detecting recurrences of cancer. Tumor markers are substances, often proteins, produced by cancer cells or by normal cells in response to cancer presence. They can be found in the blood, urine, or tissue of patients.

When a patient undergoes treatment for cancer, such as chemotherapy or immunotherapy, healthcare providers often use tumor markers to determine how well the treatment is working. A decline in the level of a specific tumor marker might indicate that the treatment is effective, whereas an increase or plateau could suggest that the disease is not responding or is progressing. Additionally, after treatment is completed, periodic measurement of tumor markers can help identify any recurrence of cancer at an early stage, providing a crucial window for intervention.

The other options have limitations in their application. For instance, tumor markers are not used for the direct treatment of patients; instead, they play a role in monitoring existing conditions. Furthermore, while some tumor markers can assist in diagnosing certain types of cancer, they are not exclusive to the identification of primary cancers only and are not intended to replace traditional diagnostic methods such as imaging or biopsies, which are essential for comprehensive cancer evaluation. Thus, the usage of tumor markers is integral