Table 1.
Reporting Elements for IHC and FISH
| IHC/FISH shared elements |
| Patient identification information |
| Physician identification |
| Date of service |
| Specimen identification (case and block No.) |
| Specimen site and type |
| Specimen fixative type |
| Time to fixation (if available) |
| Duration of fixation (if available) |
| Method used (specifics test/vendor and if FDA-approved) |
| Image analysis method (if used) |
| Adequacy of sample for evaluation (adequate No. of invasive tumor cells present) |
| IHC-specific elements |
| Antibody clone/vendor |
| Controls (high protein expression, low-level protein expression, negative protein expression, internal) |
| Results |
| • Percentage of invasive tumor cells exhibiting complete membrane staining • Uniformity of staining: present/absent • Homogenous, dark circumferential pattern: present/absent |
| Interpretation: Positive (for HER2 protein expression), equivocal (FISH will be done and reported), negative (for HER2 protein expression), not interpretable. |
| FISH-specific elements |
| Probe(s) identification |
| Controls (amplified, equivocal, and nonamplified, internal) |
| Results |
| • No. if invasive tumor cells counted • No. of observers • Average No. of HER2 signals/nucleus or tile • Average No. of CEP 17 chromosome probes/nucleus or tile • Ratio of average HER2 signals/CEP 17 probe signals |
| Interpretation: Positive (amplified), equivocal, negative (not amplified), not interpretable. If IHC is being done because of problems with assay or results, this should also be indicated. |
NOTE. If an FDA-approved method is used, it should be stated. If the FDA-approved method has been modified, a statement in the report should be included indicating what modifications were made and that the changes have been validated. If the test is not FDA-approved or if an FDA-approved test has been modified, a clear statement must be made that the laboratory reporting the results take responsibility for test performance.
Abbreviations: IHC, immunohistochemistry; FISH, fluorescence in situ hybridization; FDA, US Food and Drug Administration; HER2, human epidermal growth factor receptor 2; CEP 27, entromeric chromosome 17–specific probe. Tile is unit used for image system counting.