Cancer biomarker that are currently used in cancer therapy and under evaluation in clinical trials

Cancer biomarkers significantly advance precision oncology by giving physicians guidance about treatment options based on the molecular characteristics of a person's tumor, allowing for personalized cancer care. When used collectively, the identification of these cancer biomarkers will lead to better selection of appropriate therapies, facilitate monitoring of response to treatment, and provide rapid evaluation of treatment efficacy. Genetic mutations that are frequently used as cancer biomarkers include mutant forms of particular oncogenes like EGFR (epidermal growth factor receptor), BRAF (B-Raf proto-oncogene), and NTRK (neurotrophic receptor kinase). Targeted therapies that have been successfully developed to treat EGFR mutations in lung cancer and V600E BRAF mutations in melanoma have been proven to be effective. The use of drug therapies such as imlunestrant that specifically target ESR1 mutations in advanced breast cancer cases reflects the incorporation of genetic biomarkers into routine clinical decision making. Non-invasive liquid biopsy technologies, such as the MI Cancer Seek assay, permit the identification of the driver mutations (e.g., PIK3CA, EGFR, BRAF), the presence of microsatellite instability (MSI), and the mutational burden of a tumor tissue sample, providing predictive markers for both targeted and immunotherapeutic treatment options. The further development of HRD and the viral onco-genes have widened the options available for a biomarker-based therapy. This chapter will provide an in-depth explanation of an Introduction to Cancer Biomarkers and new research developments.