Table 2 Overall concordance between ctDNA and tissue DNA based on time interval between blood draw and tissue biopsy and on whether primary or metastatic tumor was biopsied (N = 66)
From: Clinical correlates of blood-derived circulating tumor DNA in pancreatic cancer
Patients with pancreatic ductal adenocarcinoma who had both ctDNA and tissue DNA sequencing (N = 66) | Â | Â | ||||||||
|  |  | Tissue DNA (+) | Tissue DNA (−) | Overall concordance* (%) | Kappa (SE) |  |  | |||
TP53 | ctDNA (+) | 29 (44%) | 4 (6.1%) | 61 | 0.21 (0.1) | Â | Â | |||
ctDNA (−) | 22 (33%) | 11 (17%) |  |  | ||||||
KRAS | ctDNA (+) | 28 (42%) | 0 (0.0%) | 52 | 0.14 (0.1) | Â | Â | |||
ctDNA (−) | 32 (48%) | 6 (9.1%) |  |  | ||||||
Concordance depending on whether primary tumor or metastatic site was biopsied | ||||||||||
| Â | Â | Primary tumor (n = 41) | Metastatic sites (n = 25) | Â | ||||||
|  |  | Tissue DNA (+) | Tissue DNA (−) | Overall concordance* (%) | Kappa (SE) | Tissue DNA (+) | Tissue DNA (−) | Overall concordance* (%) | Kappa (SE) | P value |
TP53 | ctDNA (+) | 14 (34%) | 1 (2.4%) | 54 | 0.19 (0.1) | 15 (60%) | 3 (12%) | 72 | 0.27 (0.2) | 0.20 |
ctDNA (−) | 18 (44%) | 8 (20%) | 4 (16%) | 3 (12%) | ||||||
KRAS | ctDNA (+) | 14 (34%) | 0 (0.0%) | 39 | 0.05 (0.04) | 14 (56%) | 0 (0.0%) | 72 | 0.39 (0.2) | 0.01 |
ctDNA (−) | 25 (61%) | 2 (4.9%) | 7 (28%) | 4 (16%) | ||||||
Concordance based on time interval between blood draw and tissue biopsy | ||||||||||
|  |  | ≤ 6 months (n = 49) | >6 months (n = 17) |  | ||||||
|  |  | Tissue DNA (+) | Tissue DNA (−) | Overall concordance* (%) | Kappa (SE) | Tissue DNA (+) | Tissue DNA (−) | Overall concordance* (%) | Kappa (SE) | P value |
TP53 | ctDNA (+) | 25 (51%) | 3 (6.1%) | 65 | 0.24 (0.1) | 4 (24%) | 1 (5.9%) | 47 | 0.10 (0.2) | 0.25 |
ctDNA (−) | 14 (29%) | 7 (14%) | 8 (47%) | 4 (24%) | ||||||
KRAS | ctDNA (+) | 22 (45%) | 0 (0.0%) | 55 | 0.17 (0.1) | 6 (35%) | 0 (0.0%) | 41 | 0.07 (0.1) | 0.40 |
ctDNA (−) | 22 (45%) | 5 (10%) | 10 (59%) | 1 (6%) | ||||||