TABLE 2.
Comparison of HER2 testing and F1CDx analyses for ERBB. A, Concordance between HER2 testing and F1CDx results for ERBB2; (B) Conversion and oncogenic variants in ERBB2 with F1CDx
| (A) HER2 testing | F1CDx (ERBB2) | Total | ||||
|---|---|---|---|---|---|---|
| IHC | FISH | Amplification | Low amplification a | Mutation | ND | |
| 3+ | 21 | 0 | 0 | 0 | 21 | |
| 2+ | Positive | 1 | 2 | 0 | 0 | 3 |
| Negative | 0 | 0 | 2 | 22 | 24 | |
| 1+ | 1 b | 1 | 3 b | 30 | 35 | |
| 0 | 1 | 0 | 0 | 26 | 27 | |
| Total | 24 | 3 | 5 | 78 | 110 | |
| (B) Sample no | HER2 testing | F1CDx | |
|---|---|---|---|
| IHC | FISH | ERBB2 | |
| 064 | 2+ | Negative | S563C |
| 070 | 2+ | Negative | R896H |
| 035 | 1+ | D769Y | |
| 100 | 1+ | G776V | |
| 073 | 1+ | Low amplification a | |
| 079 | 1+ | Positive | Amplification/L755S |
| 022 | 0 (partially 3+) | Amplification | |
Abbreviations: F1CDx, FoundationOne® CDx, FISH, fluorescence in situ hybridization, HER2, human epidermal receptor type 2; IHC, immunohistochemical staining.
a
Low amplification: ERBB2 amplification of copy number 4 was detected.
b
One patient showed both ERBB2 amplification and mutation.