Fig. 2

Variant allele frequency (%) in plasma. Sensitizing EGFR mutations (n = 36 cases) and T790M mutations (n = 18 cases) were determined in plasma by tag-based NGS and are reported as variant allele frequency percentage (%) (a) Variant allele frequency (%) for EGFR mutations determined by tag-based NGS in two patients groups classified as positive or negative for the sensitizing mutation of EGFR based on both (black circles) or one (black squares) the methods employed in the study (b) Results of tests similar to those in b except that the L858R and T790M mutations were measured in (c) and (d), respectively. Each dot represents one patient. Solid lines represent median values. Statistical P values were derived from a Mann-Whitney test. PCR, Real Time PCR; NGS, tag-based NGS; sens mut, sensitizing mutations; pos, positive; neg, negative