Table 2 Distribution of the 840 cases analyzed by mono or double probe FISH expressed as HER2 copy number (cutoff set at 6 HER2 copies) with respect to the CISH, SISH and QPCR alternative techniques
Techniques | Class | Number of cases | FISH Copies Number <6 N=592 (%) | FISH Copies Number >=6 N=248 (%) |
|---|---|---|---|---|
IHC | 0 | 317 | 316 (99.6) | 1 (0.4) |
1+ | 183 | 179 (97.8) | 4 (2.2) | |
2+ | 109 | 86 (78.9) | 23 (21.1) | |
3+ | 231 | 11 (4.8) | 220 (95.2) | |
SISH | <6 | 417 | 409 (98) | 8 (2) |
>=6 | 170 | 4 (2.4) | 166 (97.6) | |
ND or NA | 243 | 179 | 74 | |
CISH | <6 | 89 | 88 (98.8) | 1 (0.2) |
>=6 | 115 | 49 (42.6) | 66 (57.4) | |
ND or NA | 636 | 455 | 181 | |
qPCR | <6 | 576 | 531 (92.2) | 45 (7.8) |
>=6 | 197 | 12 (6) | 185 (94) | |
ND or NA | 67 | 49 | 18 |