BiomarkerTests

BiomarkerTests are diagnostic or prognostic assays that measure biological molecules or processes to indicate health status, disease presence, progression, or response to treatment. Biomarkers can be molecular, genetic, proteomic, metabolic, or imaging-based and may be measured in blood, urine, tissue, or via noninvasive imaging.

Common categories include molecular tests (DNA/RNA sequencing), protein biomarkers (troponin, CEA, PSA), metabolite panels, imaging biomarkers (PET tracers), and circulating biomarkers such as cell-free DNA.

Applications: aiding diagnosis (e.g., troponin for myocardial injury), prognosis and risk stratification, guiding therapy selection (companion diagnostics like PD-L1 expression for checkpoint inhibitors), monitoring disease activity or treatment response, and assessing drug safety in development.

Development and evaluation require analytical validation (test accuracy and precision), clinical validation (association with clinical outcome), and demonstration of clinical utility. Quality standards and oversight typically come from regulatory agencies, clinical laboratories (CLIA in the US), accreditation bodies, and international standards such as ISO 15189.

Emerging trends include multiplex panels, liquid biopsy, and integration with electronic health data for personalized medicine. While biomarker tests hold promise for targeted care, they require careful interpretation within the clinical context.