What are Biomarkers?
Biomarkers are biological molecules found in blood, other body fluids, or tissues that are a sign of a normal or abnormal process, or of a condition or disease. In the context of cancer,
tumor biomarkers can be DNA, RNA, proteins, or metabolites that indicate the presence or progression of cancer. They can be used for
diagnosis, prognosis, and monitoring treatment response.
How Do Biomarkers Drive Cancer Treatment?
Biomarkers play a crucial role in
personalized medicine by guiding the selection of targeted therapies. These therapies are designed to specifically attack cancer cells with certain genetic mutations or protein expressions while sparing normal cells. This approach not only increases treatment efficacy but also minimizes side effects.
What Are Some Common Cancer Biomarkers?
Several biomarkers are routinely used in clinical practice. For example,
HER2 is a protein overexpressed in some breast cancers and guides the use of trastuzumab therapy. Similarly,
KRAS mutations in colorectal cancer can predict non-response to certain anti-EGFR therapies. Other examples include
BRCA1/BRCA2 mutations in breast and ovarian cancers, which can influence the decision to use PARP inhibitors.
How Are Biomarkers Discovered and Validated?
The discovery and validation of biomarkers involve several steps, beginning with basic research to identify potential biomarkers. This is followed by preclinical studies to understand their biological relevance. The next step is clinical validation, where the biomarker's effectiveness in diagnosing or predicting outcomes is tested in human studies. Finally, regulatory approval is required before they can be used in clinical practice.
What Are the Challenges in Biomarker-Driven Cancer Treatment?
Despite their promise, there are challenges in the application of biomarkers in cancer treatment. One major issue is the
heterogeneity of tumors, which can lead to variations in biomarker expression within and between tumors. Additionally, the cost and complexity of biomarker testing can limit accessibility. There is also a need for continuous research to discover new biomarkers and improve existing ones.
