Joseph R. Anticaglia, MD
Medical Advisory Board
A biomarker, in medicine, is anything that can be used to measure the health status of a person. A wide range of biomarkers is available to determine whether a person is healthy or sick. For instance, some are as simple as taking your pulse, body temperature, or measuring your blood pressure. Other biomarkers can be more complex, such as biological molecules used to identify genetic changes in cancer cells. Biomarkers can be classified as follows:
Types of Biomarkers
A) Physiologic biomarkers obtained by measuring the functions of the body, such as heart rate, respiration rate, or blood pressure. When your BP is elevated, it puts you at risk to develop a stroke, or heart disease.
B) Radiographic images have been used as biomarkers. For example, a lesion in the lung can make one suspicious of cancer, or the use of a bone density test to determine if you have osteoporosis.
C) Pathologic biomarkers (biopsies) look for the disruption of the normal cellular pattern as seen in cancer tissues.
D) Molecular biomarkers are the smallest basic unit of a chemical compound. These biomarkers can be detected in various bodily fluids such as blood, urine, cerebrospinal fluid, as well as in tissues.
A blood sample, for instance, may be used to determine your glucose level to rule out diabetes. The glucose level is the biomarker. Other examples of blood biomarkers include:
Troponin for diagnosing heart attacks
Hemoglobin A1C for monitoring diabetes
PSA (prostate-specific antigen) screening for prostate cancer
C-reactive protein (CRP) for inflammation and infection
LDL (Low density lipoprotein) for cardiovascular disease.
Albumin is a protein found in the blood; when it spills over into the urine it’s a biomarker for kidney disease. Meningococcal bacteria when found in the cerebrospinal fluid is a biomarker for meningitis. After an individual has received a tissue diagnosis of cancer, biomarkers can be useful in determining the prognosis, and the predictive response to treatment of that cancer.
Clinical Types of Biomarkers
Another aspect of looking at biomarkers is to categorize them according to their clinical applications. Diagnostic biomarkers, for instance, in the context of cancer can be used to identify the type of cancer, determine the severity of the disease, and offer guidance as to appropriate treatment.
Clinical biomarkers can offer information concerning the optimal dose, and safety of medications provided to patients. They can monitor a patient’s response to treatment. Is the medication, or radiation therapy or chemotherapy working? Are there recurrences — will the cancer return? Is the person’s health improving or worsening? Below are seven types of clinical biomarkers.
7 Clinical Biomrkers
- Diagnostic Biomarker —
Confirm the presence of a disease or condition.
- Monitoring Biomarkers —
Evaluate the status of a disease or condition. Is it present? Has it spread to other parts of the the body?
- Pharmacodynamic Biomarkers —
assess the response to drug tratment. Is the medication working? Side effects?
- Predictive Biomarkers —
Predict the likelihood of developing a favorable or negative response to treatment.
- Prognostic Biomarkers —
attempt to identify the likely outcome of a disease or a condition — Is the disease or conditon progressing? Is it in remmission? Is there, any evidence of of the disease?
- Susceptibility Biomarkers —
evaluate the risk of a person to develop a condition or disease.
- Safety Biomarkers —
tell in advance the harmful effects of drugs, or other medical intervenyions.
Biomarkers have become an essential tool in clinical practice, and in medical research. As technology, and molecular biology advance, new biomarkers will be discovered for various diseases. These scientific advances can help with early diagnosis, personalized treatment, and monitoring of patients leading to better outcomes.
- National Cancer Institute; Biomarker Testing for Cancer Treatment; December 14, 2021
- Robert M Califf; Biomarker definitions and their applications; Exp Biol Med (Maywood). Feb.6, 2018
- FDA; About Biomarkers and Qualification; July 7, 2021
- Jorge Manzanares … Francisco Navarrete Rueda; Biomarkers in Reference Module in Biomedical Sciences, 2021
A Biomarker, according to the National Cancer Institute, is “A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition. Also called molecular marker and signature molecule.”
Molecule: The essential characteristic of a substance, “The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.”
Cost: The cost of biomarker testing varies greatly. Be informed.
This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.