Table 2.

Concordance assessment of BRAFV600 mutations in FFPE tumor tissue and plasma cf DNA (n = 160)

Concordance for plasma cfDNA samples collected before therapy
BRAF mutation in tumor (CLIA)BRAF wild-type in tumor (CLIA)
BRAF mutation in cfDNA (Idylla)452
BRAF wild-type in cfDNA (Idylla)1796
Observed agreements141 (88%); κ, 0.74; SE, 0.06 (95% CI, 0.63–0.85)
Sensitivity73% (95% CI, 0.60–0.83)
Specificity98% (95% CI, 0.93–1.00)
Positive predictive value96% (95% CI, 0.85–0.99)
Negative predictive value85% (95% CI, 0.77–0.91)
Concordance for all plasma cfDNA samples collected at any time point
BRAF mutation in tumor (CLIA)BRAF wild-type in tumor (CLIA)
BRAF mutation in cfDNA (Idylla)482
BRAF wild-type in cfDNA (Idylla)1496
Observed agreements144 (90%); κ, 0.78; SE, 0.05 (95% CI, 0.68–0.88)
Sensitivity77% (95% CI, 0.65–0.87)
Specificity98% (95% CI, 0.93–1.00)
Positive predictive value96% (95% CI, 0.86–0.99)
Negative predictive value87% (95% CI, 0.80–0.93)