tumor marker
A measurable substance in blood, urine, or tissue that may indicate the presence of cancer or monitor treatment response.
Full Definition
Tumor markers are biological substances, typically proteins, hormones, or genetic material, that are produced by cancer cells or by the body in response to cancer. These markers can be measured in blood, urine, stool, or tissue samples and serve various clinical purposes including cancer detection, prognosis assessment, treatment monitoring, and recurrence surveillance. Examples include PSA for prostate cancer, CA-125 for ovarian cancer, and CEA for colorectal cancer. However, tumor markers are rarely diagnostic alone and must be interpreted within clinical context.
Usage
Usage note: Distinguish from general biomarkers; tumor markers specifically relate to cancer detection or monitoring.
In Context
- "Serial tumor marker levels demonstrated excellent treatment response to chemotherapy." — Follow-up report
- "The elevated tumor marker prompted further imaging to assess for disease recurrence." — Laboratory interpretation