Table 1. Mutations tested in cfDNA and concordance between tumor tissue and cfDNA.

Mutations tested
Gene	Exon	Mutation type
BRAF	15	V600E
		V600K
EGFR	19	Δ E746_A750 (2235_2249del15)
		Δ E746_A750 (2235_2250del15)
		Δ E746_S752 ins V
		Δ L747_A750 ins P
		Δ L747_T751
		Δ L747_P753 ins S
	20	T790M
	21	L858R
KRAS	2	G12S
		G12R
		G12C
		G12D
		G12A
		G12V
		G13D
PIK3CA	9	E542K
		E545K
	20	H1047R
		H1047L
Concordance between mutation testing of tumor tissue and cfDNA
TESTED (N = 137)	BRAF mutation in tumor	BRAF wild-type in tumor
BRAF mutation in cfDNA	29	4
BRAF wild-type in cfDNA	9	95
Observed agreements	124 (91%); Kappa 0.75, SE 0.06; 95 CI% 0.63–0.88
Sensitivity	76% (95% CI 0.60–0.89)
Specificity	96% (95% CI 0.90–0.99)
Positive predictive value	88% (95% CI 0.72–0.97)
Negative predictive value	91% (95% CI 0.84–0.96)
TESTED (N = 79)	EGFR mutation in tumor	EGFR wild-type in tumor
EGFR mutation in cfDNA	5	1
EGFR wild-type in cfDNA	0	73
Observed agreements	78 (99%); Kappa 0.90, SE 0.10; 95 CI% 0.71–1.00
Sensitivity	100% (95% CI 0.48–1.00)
Specificity	99% (95% CI 0.93–1.00)
Positive predictive value	83% (95% CI 0.36–0.97)
Negative predictive value	100% (95% CI 0.95–1.00)
TESTED (N = 121)	KRAS mutation in tumor	KRAS wild-type in tumor
KRAS mutation in cfDNA	49	8
KRAS wild-type in cfDNA	12	52
Observed agreements	101 (83%); Kappa 0.67, SE 0.07; 95 CI% 0.54–0.80
Sensitivity	80% (95% CI 0.68–0.89)
Specificity	87% (95% CI 0.75–0.94)
Positive predictive value	86% (95% CI 0.74–0.94)
Negative predictive value	81% (95% CI 0.70–0.90)
TESTED (N = 107)	PIK3CA mutation in tumor	PIK3CA wild-type in tumor
PIK3CA mutation in cfDNA	12	8
PIK3CA wild-type in cfDNA	2	85
Observed agreements	97 (91%); Kappa 0.65, SE 0.10; 95 CI% 0.46–0.85
Sensitivity	86% (95% CI 0.57–0.98)
Specificity	91% (95% CI 0.84–0.96)
Positive predictive value	60% (95% CI 0.36–0.81)
Negative predictive value	98% (95% CI 0.92–1.00)