Table 2. EGFR Exon 19 del and Exon 21 L858R Mutations Detected in Plasma cfDNA (ddPCR) Versus Paired Tumor Tissues (ARMS).

Plasma cfDNA	Tumor tissues		Total	Sensitivity	Specificity	Consistency rate	κ	P
	+	−
Exon19 del or Exon 21L858R
+	57	4	61	61.3%	96.7%	81.4%	0.605	<0.001
−	36	118	154
Total	93	122	215
Exon 19del
+	26	2	28	57.8%	98.8%	90.2%	0.657	<0.001
−	19	168	187
Total	45	170	215
Exon 21L858R
+	31	3	34	64.6%	98.2%	90.7%	0.701	<0.001
−	17	164	181
Total	48	167	215