Table 1 Categories of biomarkers and diseases for which different markers have clinical relevance
Types of Biomarkers | Definition | Application | Diseases for Clinical Relevance | References |
|---|---|---|---|---|
Diagnostic Biomarker | A biomarker used to detect or confirm presence of a disease or condition of interest, alternatively, to identify individuals with a subtype of the disease | Histology/ Histopathology IDH1/2 mutation 1p/19q codeletion TERT gene promoter mutation MGMT promoter methylation | Oligodendrogliomas: 1p/19q codeletion Glioblastomas: MGMT promoter methylation Gliomas: TERT promoter mutation | |
Monitoring Biomarker | A biomarker measured continuously for evaluating status of a disease or medical condition or for evidence of exposure to (or effect of) a medical product or an environmental agent | Contrast enhanced MRI brain Circulating exosomes Circulating microRNAs | Brain tumor: MRI Contrast enhanced tumor/nontumor enhancing tissues Brain metastases: Cancer-derived exosomes for Immune interactions and therapeutic implications Chronic lymphocytic leukemia (lymphoid malignancy): MicroRNAs (miRNAs) are a class of small noncoding RNAs | |
Pharmacodynamic Biomarker / Response Biomarker | Pharmacodynamic and response biomarkers use to reveal that biological response or latently advantageous or harmful, has occurred in an individual who has been exposed to a medical product or an environmental agent As a pharmacodynamic biomarker pharmacologic response in humans, or surrogate endpoint of earlier-phase it depends on characteristic mark by the level of clinical validation | Contrast enhanced MRI brain Reduced malignant cell count in CSF cytology/flow cytometry 18F-FDG PET | Brain tumor,metastases in neuroimaging: MRI Contrast enhanced tumor/nontumor enhancing tissues Occult leptomeningeal disease, malignant hematopoietic cells: CNS involvement, cancer cells in the CSF Glioblastoma: Radiopharmaceuticals evaluated in clinical studies for oncology, pharmacodynamic biomarker | |
Predictive Biomarker | A biomarker used to identify individuals who are more probably than similar individuals without the biomarker to experience an advantageous or disadvantageous effect from exposure to a medical product or an environmental agent | IDH1/2 mutation 1p/19q codeletion MGMT promoter methylation | Glioma: IDH1/2 mutation Oligodendrogliomas: 1p/19q codeletion Glioblastomas: MGMT promoter methylation | |
Prognostic biomarker | A biomarker used to identify likelihood of a clinical event, disease recurrence or progression in patients who have the disease or medical condition of interest | IDH1/2 mutation 1p/19q codeletion MGMT promoter methylation SHHÂ gene pathway mutations, Chromosome 17p deletions and TP53 mutations | Glioma: IDH1/2 mutation Oligodendrogliomas: 1p/19q codeletion Glioblastomas: MGMT promoter methylation Medulloblastoma: SHHÂ gene pathway mutations | |
Susceptibility/Risk Biomarker | A biomarker that reveals the potential for progressing a disease or medical condition in an individual who does not currently have clinically obvious disease or the medical condition | Inherited genetic disorders APOE gene variations DNA repair gene polymorphisms | Alzheimer's disease: APOE genotype | |
Safety Biomarker | A biomarker measured before or after an exposure to a medical product or an environmental agent to reveal the likelihood, existence, or range of toxicity as an adverse effect | Complete blood cell count Genetic polymorphisms | Gliomas: Evaluating preoperative complete blood cell count-derived inflammatory biomarkers Diffuse glioma: MGMT gene polymorphisms with myelotoxicity, severe hematological toxicity treated with TMZ | |
Validated Surrogate Endpoint | An endpoint supported by an obvious mechanistic rationale and clinical data providing strong evidence that an effect on the surrogate endpoint predicts a specific clinical advantage | Progression-free survival Time-to-progression | Tumor correlate with overall survival in progression-free survival Randomization to tumor progression or death in time-to-progression |