[Hot topics of circulating tumor DNA testing in breast cancer]

The progress of gene detection technologies represented by next generation sequencing (NGS) and digital PCR laid a foundation for studies of circulating tumor DNA (ctDNA) in breast cancer. In 2014, the NGS workgroup organized by the College of American Pathologists (CAP) published the College of American Pathologists' Laboratory Standards for Next-Generation Sequencing Clinical Tests, which provides a blueprint for the standardization of gene testing. In 2015, the Guidelines for Diagnostic Next-generation Sequencing published by the European Society of Human Genetics claimed that NGS is unacceptable in clinical practice before studies guided by guidelines are approved. Although existing studies show the benefits of ctDNA testing in disease monitoring and prognosis analyzing, we have a ways to go to normalize the procedure and build strict detection criteria.