Table 2.
Algorithm, Technique, and Reporting for ERBB2/HER2 (Human Epidermal Growth Factor Receptor 2) Testing in Endometrial Serous Carcinoma (ESC)
| No. (%) | |
|---|---|
|
| |
| Algorithm used for ERBB2/HER2 testing in ESC | 286 |
| IHC with reflex to ISH for equivocal results | 254 (88.8) |
| Both IHC and ISH testing | 20 (7.0) |
| ISH only testing | 2 (0.7) |
| ISH with reflex to IHC for equivocal results | 1 (0.3) |
| Othera | 9 (3.1) |
| ISH technique used for ERBB2/HER2 testing in ESC | 213 |
| FISH | 187 (87.8) |
| CISH | 20 (9.4) |
| Otherb | 6 (2.8) |
| Scoring criteria/guidelines used to report ERBB2/HER2 IHC and ISH in ESC | 281 |
| ASCO/CAP 2018 guideline for breast carcinoma (PMID 29846122) | 195 (69.4) |
| ASCO/CAP 2013 guideline for breast carcinoma (PMID 24101045) | 5 (1.8) |
| ASCO/CAP 2007 guideline for breast carcinoma (PMID 19548375) | 4 (1.4) |
| Fader et al17 2018 clinical trial guidelines requiring >30% strong complete or basolateral/lateral IHC or HER2/CEP17 ratio ≥2.0 (PMID 32649220) | 45 (16.0) |
| “Overall” assessment of positive versus negative result | 10 (3.6) |
| Original FDA scoring criteria (HercepTest package insert) for breast carcinoma (PMID 10888772) | 14 (5.0) |
| Otherc | 8 (2.9) |
Abbreviations: ASCO, American Society of Clinical Oncology; CAP, College of American Pathologists; CISH, chromogenic (bright-field) ISH; FDA, US Food and Drug Administration; FISH, fluorescence ISH; IHC, immunohistochemistry; ISH, in situ hybridization.
a
Other responses: IHC only (4), clinician request (3), IHC in laboratory with ISH send-out for 2+ and 3+ (1), and no algorithm defined (1).
b
Other responses: dual ISH (3) and silver ISH (2).
c
Other responses: CAP/American Society for Clinical Pathology/ASCO gastroesophageal adenocarcinoma (PMID 27841667) (4) and in-house guideline (1).