Table 4.
Concordance assessment of KRASG12/G13 mutations in plasma cell-free DNA (cfDNA) and formalin-fixed, paraffin-embedded (FFPE) tumor tissue or urine cfDNA from patients with advanced cancers.
| Concordance for plasma samples
collected before systemic therapy tested for
KRASG12/G13 mutations versus FFPE tumor
samples tested in the clinical laboratory | ||
| Number of patients, N=33 | KRASG12/G13 Mutation in Tumor | KRASG12/G13 Wild-Type in Tumor |
| KRASG12/G13 mutation in plasma, no. of patients | 22 | 0 |
| KRASG12/G13 wild-type in plasma, no. of patients | 2 | 9 |
| Observed concordance | 31 (94%); kappa, 0.86; SE, 0.10; 95% CI, 0.67–1.00 | |
| Sensitivity | 92% (95% CI, 0.73–0.99) | |
| Specificity | 100% (95% CI, 0.66–1.00) | |
| Positive predictive value | 100% (95% CI, 0.85–1.00) | |
| Concordance for plasma and
urine samples collected before systemic therapy tested for
KRASG12/G13 mutations | ||
| Number of patients, N=33 | KRASG12/G13 mutation in plasma | KRASG12/G13 wild-type in plasma |
| KRASG12/G13 mutation in urine, no. of patients | 13 | 2 |
| KRASG12/G13 wild-type in urine, no. of patients | 9 | 9 |
| Observed concordance | 22 (67%); kappa, 0.35; SE, 0.15; 95% CI, 0.07–0.64 | |
| Sensitivity | 59% (95% CI, 0.36–0.79) | |
| Specificity | 82% (95% CI, 0.48–0.98) | |
| Positive predictive value | 87% (95% CI, 0.60–0.98) | |