Emerging Role of Liquid Biopsy In Precision Medicine

Introduction: Cancer is a heterogeneous disease characterized by diverse genetic alterations that cause different treatment response (۱). Radiotherapy is one of the effective cancer treatments, and it may use alone or as an adjunct to other treatments like chemotherapy. Currently patients with the same stage of the certain cancer are treated in the same way (۲). Meanwhile, these patients may have various side effects caused by irradiation. In recent years, several treatment strategies have been investigated in order to personalize treatments. One way to classify patients is to use biomarkers that can stratify patients based on the possibility of side effects (۳). Liquid biopsy is an emerging method for the detection of cancer that referring to analysis of patient liquid specimens such as blood, cerebrospinal fluid (CSF), serum and saliva. This method is non-invasive and real-time in compare with tissue biopsy that use as gold standard (۴, ۵). The main biological components of liquid biopsies are circulating tumor cells (CTC), circulating tumor DNA (ctDNA) and exosomes. that these components are used as successful techniques in identifying mutations presents, tumor response assessment and prognosticate outcome (۶).Methods: In this presentation, PubMed, Scopus and Google Scholar databases were searches by using the keywords such as liquid biopsy, precision medicine, radiotherapy and radiation sensitivity from ۲۰۱۸ to ۲۰۲۲ to identify relevant articles.Result: Six selected articles include description of liquid biopsy and its components. In the following, these components were reviewed for their advantages and applications in precision medicine. Finally, the techniques for isolation of each group were introduced completely.Conclusion: Based on the results, liquid biopsy strategies offer non-invasive tools for diagnosis and monitoring response to therapy and it is newly arrived in clinical practice. Liquid biopsy can shift the patient management paradigm to precision therapy based on tumor molecular biology. Thereinto, in liquid biopsy components, exosomes show high sensitivity, stability and specificity against the others.