Lexicon · NucLex for innovators
Biomarker
Fully specified name: Biomarker (concept)
A measured characteristic used as an indicator of a biological process or response.
- Scope note
- Specify measurement, intended interpretation, and validation context.
- Synonyms
- None recorded as true synonyms in this context.
- Monograph
- Precision nuclear oncology (draft)
- External mappings
- None recorded. In W0 no mapping to SNOMED CT® or any external authority is asserted for this entry. A future mapping record will carry source system, identifier, version, relation type, evidence, author, confidence where meaningful, and review state.
- Formal status
- Editorial entry only. It is not part of any released ontology and a prose edit here changes no formal definition.
Draft. This entry is an unreviewed draft. Its sources have not been checked by a named person and no domain reviewer has approved it. Treat every claim as provisional.
Notes
A biomarker is something measured in or about a person that is taken to indicate a biological state: the presence of disease, its likely course, the probability of responding to a treatment, or the effect of a treatment once given. The measurement may be a laboratory value, a feature of an image, a genetic variant, or a quantitative imaging index. What makes it a biomarker is the interpretive use, not the measurement itself.
Three elements must be stated for a biomarker claim to be reusable. The measurement: which analyte or image feature, by which method, with which units and reference ranges. The intended interpretation: diagnostic, prognostic, predictive, pharmacodynamic, monitoring, or safety, since the same measurement can serve several of these and the evidence for each is different. The validation context: the population, disease setting, and study design in which the association was shown. A marker validated for one purpose in one population carries no automatic warrant elsewhere.
In nuclear medicine, imaging findings are frequently used as biomarkers of target expression, and quantitative uptake measures as biomarkers of response. The acquisition protocol, reconstruction, and analysis method are part of the measurement and belong in the record. NucLex treats a biomarker as a link between a measurement concept and an interpretation concept, with its own evidence and context.