Global Health
What is a biomarker?
The term biomarker or biological marker refers to a big selection of measures that record what is occurring in a cell or organism at a given time. Biomarkers are objective medical symptoms (versus patient-reported symptoms) used to measure the presence or progression of a disease or the results of treatment. Biomarkers could be molecular, histological, radiographic, or physiological. Examples of biomarkers include every part from blood pressure and heart rate to basic metabolic tests and X-ray results to complex histological and genetic tests of blood and other tissues. Biomarkers are measurable and don’t define how an individual feels or functions.
Although the term biomarker is comparatively latest, medical symptoms have been utilized in clinical practice for hundreds of years. Many biomarkers, comparable to heart rate, urinalysis, and blood lead levels, are widely used and well-studied. With the event of genomics and other advances in molecular biology, latest biomarker research has entered a promising era with the potential for early diagnosis and effective, personalized treatment of many diseases. In clinical trials, biomarkers can function indirect markers of disease and help determine whether a specific therapy is effectively treating the disease. The more conventional approach of using endpoints comparable to quality of life or mortality in clinical trials could make collecting sufficient data each time-consuming and expensive. Using a biomarker-based approach can shorten the time to clinical trials and speed up product development and regulatory approval.
Types of biomarkers
Types of biomarkers include:
- Molecular – have biophysical properties that enable their measurement in biological samples (e.g. plasma, serum, cerebrospinal fluid, bronchoalveolar lavage, biopsy)
- Radiographic – obtained from imaging studies
- Histological – reflect biochemical or molecular changes in cells, tissues or fluids
- Physiological – measures of processes occurring within the body
Examples:
- Blood glucose (molecular)
- Classification and staging of tumors (histological)
- Bone mineral density (radiographic)
- Blood pressure (physiological)
Biomarker Applications
Biomarkers have many useful applications in healthcare, including disease prevention and detection, determining individual disease risk, and monitoring disease. They will also be used to measure the security or toxicity of a therapeutic regimen or certain environmental exposures.
| Screen adaptation | Prostate-specific antigen (PSA) | Prostate cancer |
| Fecal occult blood test | Colon cancer | |
| Vulnerability/Risk | Breast Cancer Gene 1 and a pair of Mutations (BRCA 1/2) | Predisposition to breast cancer |
| Factor V Leiden | Predisposition to the event of thrombosis | |
| Apolipoprotein C | Predisposition to Alzheimer’s disease | |
| Human papillomavirus (HPV) | Predisposition to cervical cancer | |
| Diagnostic | Troponin-I | Coronary ischemia |
| Sweat chloride | Cystic fibrosis | |
| Ejection fraction (EF) | Cardiomyopathy/congestive heart failure | |
| Glomerular filtration rate (GFR) | Chronic kidney disease | |
| Prognostic | BRCA1/2 | Likelihood of a second cancer occurring in women with breast cancer |
| Chromosome 17p deletions and TP53 mutations | Likelihood of death in patients with chronic lymphocytic leukemia | |
| Monitoring | Serum low-density lipoproteins (LDL) | Response to lipid-lowering medications |
| International Normalized Ratio (INR) | Effectiveness of anticoagulant treatment | |
| Cancer antigen 125 (CA-125) | Ovarian cancer disease status or burden | |
| Hemoglobin a1c | Response to antihyperglycemic drugs or lifestyle changes | |
| Viral load | Response to antiretroviral therapy for human immunodeficiency virus (HIV) | |
| Security | Liver aminotransferases and bilirubin | Hepatotoxicity |
| Serum creatinine | Nephrotoxicity | |
| Serum potassium | Hypo- or hyperkalemia while taking diuretics, angiotensin-converting enzyme inhibitors | |
| Corrected QT interval (QTc) | Evaluation of the Potential of Drugs Inducing Ventricular Tachycardia | |
| Bisphenol A (BPA) in serum | Measured while pregnant; can predict antagonistic birth outcomes comparable to preterm birth; helps improve public safety through the usage of BPA-free plastics. | |
The use of established biomarkers in basic and clinical research, in addition to in clinical practice, has grow to be widespread, and their inclusion as endpoints in clinical trials is now widely accepted. Biomarkers allow for a greater understanding of disease processes and the ways during which drugs work to combat disease. This knowledge could be used to diagnose diseases earlier or prevent them before they occur. Biomarkers could be used to enhance the efficacy and safety of existing drugs and to develop latest drugs. New molecular biomarkers have the potential to personalize disease prevention and treatment, making healthcare delivery more precise, protected, and cost-effective, ultimately improving health outcomes (Raby, 2023).
Amur, S. (n.d.) Biomarker Terminology: Speaking the Same Language. US Food and Drug Administration Online Educational Materials Retrieved from https://www.fda.gov/files/BIOMARKER-TERMINOLOGY–SPEAKING-THE-SAME-LANGUAGE.pdf
BEST (Biomarkers, EndpointS, and other Tools) Resource. May 2, 2018 FDA-NIH Biomarker Working Group. Downloaded from https://www.ncbi.nlm.nih.gov/books/NBK326791/pdf/Bookshelf_NBK326791.pdf
Lou, E., Johnson M., Sima, C., Gonzalez-Espinoza, R., Fleisher, M., Kris, M., and Azzoli, C., (2014). Serum biomarkers to evaluate histology and end result in patients with metastatic lung cancer. Cancer Biomarkers, 14(4). doi: 10.3233/CBM-140399
Raby, B. (2023, September 6). Personalized medicine. Current. https://www.uptodate.com/contents/personalized-medicine