{"entity":{"id":"biomarker","kind":"term","name":"Biomarker","aka":["biomarkers","marker","markers","molecular marker","molecular markers","predictive biomarker","predictive biomarkers","prognostic biomarker","prognostic biomarkers","biomarker-positive","biomarker-negative","biomarker-selected","biomarker-driven","biomarker-defined"],"tldr":"Anything measurable in the body or tumour that tells you something useful: what kind of cancer it is, how it is likely to behave, or which drug is likely to work.","summary":"Biomarkers come in three main flavours: diagnostic (what is this?), prognostic (how will it behave regardless of treatment?) and predictive (will this particular treatment work?); ER, PD-L1, HER2, EGFR mutations and MSI are predictive biomarkers with drugs attached to them, PSA and CA-125 are tumour markers used for monitoring, and Ki-67 is prognostic. Predictive biomarkers underpin precision oncology, letting trials enrol only patients likely to benefit and sparing others a useless drug, and a test validated for this purpose becomes a companion diagnostic. Many biomarkers remain imperfect, PD-L1 most famously, and validating and standardising them is one of the field's chronic bottlenecks.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Biomarker_(medicine)","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Biomarker_(medicine)"}],"tags":[],"related":["tumour-marker","ihc","genomic-profiling","companion-diagnostic-term","overexpression","prognosis","ctdna","tmb","msi"],"cancers":[],"sections":[],"technologies":["companion-diagnostic","cgp","histopathology-ihc"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":["cancer-biomarkers","international-journal-of-biological-markers","tumour-biology"],"dependsOn":[],"notes":[],"category":"Clinic basics"},"route":"/terms/biomarker/","neighbours":{"term":[{"id":"cancer-drivers-vs-actionable","kind":"term","name":"Actionable genomic biomarkers","route":"/terms/cancer-drivers-vs-actionable/"},{"id":"analytical-vs-clinical-validation","kind":"term","name":"Analytical versus clinical validation","route":"/terms/analytical-vs-clinical-validation/"},{"id":"biopsy","kind":"term","name":"Biopsy","route":"/terms/biopsy/"},{"id":"ctdna","kind":"term","name":"Circulating tumour DNA (ctDNA)","route":"/terms/ctdna/"},{"id":"companion-diagnostic-term","kind":"term","name":"Companion diagnostic","route":"/terms/companion-diagnostic-term/"},{"id":"biomarker-stratified-design","kind":"term","name":"Enrichment and biomarker-stratified designs","route":"/terms/biomarker-stratified-design/"},{"id":"gene-expression","kind":"term","name":"Gene expression","route":"/terms/gene-expression/"},{"id":"genomic-profiling","kind":"term","name":"Genomic profiling","route":"/terms/genomic-profiling/"},{"id":"ihc","kind":"term","name":"Immunohistochemistry (IHC)","route":"/terms/ihc/"},{"id":"immunotherapy-response","kind":"term","name":"Immunotherapy response and its prediction","route":"/terms/immunotherapy-response/"},{"id":"msi","kind":"term","name":"Microsatellite instability (MSI-H) / mismatch repair deficiency (dMMR)","route":"/terms/msi/"},{"id":"overexpression","kind":"term","name":"Overexpression","route":"/terms/overexpression/"},{"id":"prognosis","kind":"term","name":"Prognosis","route":"/terms/prognosis/"},{"id":"roc-auc","kind":"term","name":"ROC-AUC, PR-AUC and time-dependent AUC","route":"/terms/roc-auc/"},{"id":"targeted-therapy-term","kind":"term","name":"Targeted therapy","route":"/terms/targeted-therapy-term/"},{"id":"tumour-marker","kind":"term","name":"Tumour marker","route":"/terms/tumour-marker/"},{"id":"tmb","kind":"term","name":"Tumour mutational burden (TMB)","route":"/terms/tmb/"}],"technology":[{"id":"cea-surveillance-colorectal","kind":"technology","name":"CEA surveillance after colorectal cancer surgery","route":"/technologies/cea-surveillance-colorectal/"},{"id":"companion-diagnostic","kind":"technology","name":"Companion diagnostics","route":"/technologies/companion-diagnostic/"},{"id":"cgp","kind":"technology","name":"Comprehensive genomic profiling","route":"/technologies/cgp/"},{"id":"histopathology-ihc","kind":"technology","name":"Histopathology & immunohistochemistry","route":"/technologies/histopathology-ihc/"},{"id":"serum-tumour-markers","kind":"technology","name":"Serum tumour markers: proper use and misuse","route":"/technologies/serum-tumour-markers/"}],"journal":[{"id":"cancer-biomarkers","kind":"journal","name":"Cancer biomarkers","route":"/journals/cancer-biomarkers/"},{"id":"jitc","kind":"journal","name":"Journal for ImmunoTherapy of Cancer","route":"/journals/jitc/"},{"id":"international-journal-of-biological-markers","kind":"journal","name":"The International journal of biological markers","route":"/journals/international-journal-of-biological-markers/"},{"id":"tumour-biology","kind":"journal","name":"Tumour biology","route":"/journals/tumour-biology/"},{"id":"world-journal-of-surgical-oncology","kind":"journal","name":"World journal of surgical oncology","route":"/journals/world-journal-of-surgical-oncology/"}],"drug":[{"id":"prosigna","kind":"drug","name":"Prosigna (PAM50)","route":"/drugs/prosigna/"}]}}