[Genomic Analysis and Immunotherapy by Liquid Biopsy]

This year, the genetic testing for cancer genome medicine approved in Japan, and the clinical basis for this medical area is developed. Focus will likely fall not only on genetic analysis in tissues, but also on genomic analysis by liquid biopsy using patient body fluids such as blood, saliva and urine. The advantages of liquid biopsy are the fact that it is minimally invasive and the possibility of broadening the diagnosis and selection of therapeutic agents, even in cases in which it is difficult to collect tumor tissues. Liquid biopsies of cancer patients will enable, circulating tumor cell(CTC), cell free DNA(cfDNA), circulating tumor cell DNA(ctDNA), exosomes and microRNA(miRNA). The potential usefulness of liquid biopsy for cancer diagnosis, recurrence prediction and monitoring of treatment effect has been mentioned in various manuscripts. In immunotherapy, liquid genetic biomarkers for predicting the therapeutic effect of immune checkpoint inhibitors are under development worldwide. Although issues such as standardization of the measurement methods and the samples used remain, early diagnosis of cancer by liquid biopsy may become a reality in the near future.