Advances in liquid biopsy

Cancer is a lethal disease and ranks as the world’s second most prevalent cause of death. So far, tissue-based biopsy is conducted routinely to detect and monitor the progression of cancer. However, the traditional technique is deemed too invasive and cannot be used repeatedly. On the other hand, liquid biopsy, also known as blood-sample test, has recently surged and has been proved to be more and more promising. Using cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA), liquid biopsy can effectively profile the genetic landscape of cancer and can detect the presence of cancer in patients at very early stages due to its high sensitivity. Liquid biopsy is not only capable of monitoring the risk or potential of tumorigenesis, but also capable of predicting and tracking metastasis and relapse. Therefore, liquid biopsy is believed to revolutionize cancer detection, prognosis, and personalized medicine treatment. In this review, the concept, history, recent advances of liquid biopsy, and existing commercial companies’ most commonly used techniques were summarized; the advantages and disadvantages and the broad applications of liquid biopsy in various fields including cancer were discussed