Circulating-tumor DNA as an early detection and diagnostic tool.

The development of new circulating-tumor DNA (ctDNA) analysis techniques has led to an explosion of studies demonstrating exciting clinical applications. Non-invasive genotyping can characterize mutations of interest without the need for an invasive biopsy. Serial ctDNA monitoring can assess response to treatment, and potentially identify mechanisms of resistance. Perhaps most excitingly, sensitive ctDNA analysis methods allow for detection of minimally residual disease, predicting recurrence months before clinical presentation. In this review, we highlight several recent, key studies in the ctDNA field and discuss future advances which would further improve patient care.