2. WHAT IS BIOMARKER?
A bio-marker, or biological marker is a measurable
indicator of some biological state or condition. Biomarkers are
often measured and evaluated to examine normal biological
processes, pathogenic processes, or pharmacologic
responses to a therapeutic intervention. Biomarkers are used
in many scientific fields.
Biomarkers can be detected in blood, urine, tissues or other
body fluid.
3. CANCER BIOMARKER
Cancer biomarkers can include:
Proteins
Gene mutations
Gene rearrangements
Extra copies of genes
Missing genes
Other molecules
A cancer biomarker is a molecule secreted by a
tumour or a specific response of the body to the
presence of cancer.
4. In cancer research and medicine,
biomarkers are used in three
primary ways:
1. Diagnostic: To help diagnose conditions, as in the case of
identifying early stage cancers.
2. Prognostic: To forecast how aggressive a condition is, as in the
case of determining a patient's ability to fare in the absence of
treatment.
3. Predictive: To predict how well a patient will respond to
treatment.
5.
6. Questions that can be answered by cancer
biomarkers:
Prognostic
Is it likely to develop this cancer?
Diagnostic
What type of cancer is it?
Pharmacodynamics
What is the optimal dose?
Recurrence
Will the cancer return?
Predictive
Is this the optimal drug for that cancer?
7. Some Cancer Biomarkers in clinical use
Cancer Biomarker Names Cancer type Clinical uses
HER2 Breast cancer • Select patients for
trastuzumab therapy
PSA Prostate cancer • Screening
• Diagnosis
CA125 Ovarian cancer • Prognosis
• Detecting recurrence
• Monitoring therapy
Human chorionic
gonadotropin-β
Testicular cancer • Diagnosis
• Staging
• Detecting recurrence
• Monitoring therapy
CA 19-9 Pancreatic cancer • Monitoring therapy
Carcinoembryonic
antigen
Colon cancer • Monitoring therapy
• Prognosis
• Detecting recurrence
• Screening for hepatic
metastases
Thyroglobulin Thyroid cancer • Monitoring
8. Conclusion
Cancer biomarkers are crucial to discovering and developing novel
cancer therapeutics. They are also key in clinical practice, where they
have applications in risk assessment, diagnosis, prognosis, and
determination of treatment efficacy and relapse.