Table 2.
Discrepancies between FISH and GOLDFISH
| GOLDFISH (Preview) | GOLDFISH (Rereview) | Initial direct FISH | HER/ 17 ratio | Dig FISH | Repeat direct FISH | Repeat HER/17 ratio | mRNA | HercepTest | CB11 | Resolution |
|---|---|---|---|---|---|---|---|---|---|---|
| Not amplified | Not amplified | 4.9 | 1.3 | 2.9 | 2.0 | 0.6 | Negative | 3+ | 0 | FISH pseudoamplification* |
| Not amplified | Not amplified | 4.3 | 1.7 | 5.7 | 3.6 | 1.3 | Negative | 3+ | 2+ | FISH pseudoamplification* |
| Low-level amplified | Local low-level amplification | 2.1 | 1.1 | 1.7 | 2.2 | 1.0 | Negative | 0 | 0 | Most of tissue on GOLDFISH not amplified. Rare focal areas demonstrated background and low level positive GOLDFISH staining. |
| Low-level amplified | Amplified | 16.7 | 14.0 | 13.2 | See Resolution | See Resolution | Negative | 3+ | 3+ | GOLDFISH interpreted as focally positive on rereview and again on repeat staining. Repeat direct FISH demonstrated one small area with HER-2/neu amplification and only one chromosome 17 signal per nucleus. |
| Not amplified | Not amplified | 4.8 | 3.3 | 3.9 | 9.3 | 4.2 | Negative | 2+ | 2+ | Unresolved |
| Low-level amplified | Low-level amplified | 3.5 | 1.6 | 4.0 | 3.4 | 1.2 | Negative | 2+ | 0 | Unresolved |
*FISH pseudoamplification was defined as the presence of apparent low-level HER-2/neu gene amplification attributable to a polysomic state of chromosome 17, based on the results of the reference direct dual-color FISH reference standard. In such cases, the HER-2/neu gene copy number was >4, but <8 (usually between 4.1 and 5.0) and multiple copies of chromosome 17 were present, each with a nonamplified HER-2/neu gene at locus 17q11.2-q12, resulting in a HER-2/chromosome 17 ratio < 2.0.