The decision for precision.

The reproducibility of next-generation sequencing (NGS) has already been called into question for evaluating germlines. Now it’s on the chopping block for its use in liquid biopsies. Last week’s JAMA Onc pub compares results of two popular NGS platforms when used simultaneously on cell-free DNA obtained from 40 patients with metastatic prostate cancer. Of 25 patients with discovered alterations, only 3 had results that were completely congruent between the two platforms. Eesh. As a companion editorial points out, any debate over the clinical utility of precision medicine techniques (such as NGS) presupposes their analytical validity. In other words, maybe we should hit pause on the NGS cost-effectiveness controversy and first figure out what precisely the tests are even telling us.