Fig 3.

Receiver operator characteristic curve. One patient with BRAF positivity on tumor did not get testing done by next-generation sequencing (NGS) on liquid biopsy; therefore, the analysis was done on 43 patient samples. Because all 24 of the patients without BRAF mutation tested negative for cell-free DNA by droplet digital polymerase chain reaction (ddPCR) and NGS, the receiver operating characteristic curve is degenerate. On cell-free DNA testing by NGS, three of 20 patients with BRAF positivity on tumor tissue tested negative. On ddPCR, four of 19 patients with BRAF positivity on tumor tissue tested negative. The plots and areas under the curve (AUCs) are identical for ddPCR and NGS on liquid biopsy. Wilcoxon rank sum test P < .001.