Table 1.
Concordance between conventional testing and NGS.
| Variable | IDH1 R132H (IHC) | ATRX loss (IHC) | 1p/19q codeletion (FISH) | CDKN2A/B loss (FISH) | TERT promoter mutation (Sanger) | EGFR amplification (FISH) | Chr7 imbalance (FISH) | Chr10 loss (FISH) | TP53 mutation (IHC) |
|---|---|---|---|---|---|---|---|---|---|
| by CT N° samples analysed | 60 | 60 | 10 | 18 | 45 | 39 | 33 | 33 | 59 |
| Positive for both | 7 | 3 | 5 | 5 | 33 | 4 | 19 | 20 | 15 |
| Positive for CT and Negative for NGS | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 3 |
| Positive for NGS and Negative for CT | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 |
| Positive for neither | 52 | 56 | 5 | 13 | 12 | 34 | 14 | 13 | 39 |
| Cohen’s k | 0.923 | 0.848 | 1 | 1 | 1 | 0.874 | 1 | 1 | 0.800 |
| Sensitivity for CT, % | 87.50 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 88.24 |
| Specificity for CT, % | 100.00 | 98.25 | 100.00 | 100.00 | 100.00 | 97.14 | 100.00 | 100.00 | 92.86 |
| Sensitivity for NGS, % | 100.00 | 75.00 | 100.00 | 100.00 | 100.00 | 80.00 | 100.00 | 100.00 | 83.33 |
| Specificity for NGS, % | 98.11 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 95.12 |
CT, conventional testing; NGS, next generation sequencing; IHC, immunohistochemistry; FISH, fluorescence in situ hybridization.