Liquid biopsy in cancer diagnosis, therapy and prognosis

Tissue biopsy had been regarded as the gold standard for cancer diagnosis and prognosis, which plays crucial role in determining the strategy for therapy as well, however, this procedure cannot always be performed routinely owing to its invasive nature and the heterogeneity of tumor. A liquid biopsy, or blood sample, can provide the molecular signatures of cancerous lesions. In this review, background information regarding circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and circulating miRNAs will be discussed, which are the three most promising biomarkers in liquid biopsy currently. Moreover, we will not only appraise the potential approaches for biomarkers analysis, but also consider their applications in personalized oncology and in cancer research.