Quantification of human epidermal growth factor receptor 2 immunohistochemistry using the ventana image analysis system: Correlation with gene amplification by fluorescence in situ hybridization: The importance of instrument validation for achieving high (> 95%) concordance rate

Jake Dennis, Rezvaneh Parsa, Donnie Chau, Prasad Koduru, Yan Peng, Yisheng Fang, Venetia Rumnong Sarode

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

The use of computer-based image analysis for scoring human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) has gained a lot of interest recently. We investigated the performance of the Ventana Image Analysis System (VIAS) in HER2 quantification by IHC and its correlation with fluorescence in situ hybridization (FISH). We specifically compared the 3+ IHC results using the manufacturer's machine score cutoffs versus laboratory-defined cutoffs with the FISH assay. Using the manufacturer's 3+ cutoff (VIAS score; 2.51 to 3.5), 181/536 (33.7%) were scored 3+, and FISH was positive in 147/181 (81.2%), 2 (1.1%) were equivocal, and 32 (17.6%) were FISH (-). Using the laboratory-defined 3+ cutoff (VIAS score 3.5), 52 (28.7%) cases were downgraded to 2+, of which 29 (55.7%) were FISH (-), and 23 (44.2%) were FISH (+). With the revised cutoff, there were improvements in the concordance rate from 89.1% to 97.0% and in the positive predictive value from 82.1% to 97.6%. The false-positive rate for 3+ decreased from 9.0% to 0.8%. Six of 175 (3.4%) IHC (-) cases were FISH (+). Three cases with a VIAS score 3.5 showed polysomy of chromosome 17. In conclusion, the VIAS may be a valuable tool for assisting pathologists in HER2 scoring; however, the positive cutoff defined by the manufacturer is associated with a high false-positive rate. This study highlights the importance of instrument validation/calibration to reduce false-positive results.

Original languageEnglish (US)
Pages (from-to)624-631
Number of pages8
JournalAmerican Journal of Surgical Pathology
Volume39
Issue number5
DOIs
StatePublished - Apr 28 2015

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Keywords

  • concordance
  • HER2
  • Ventana Image Analysis System

ASJC Scopus subject areas

  • Anatomy
  • Pathology and Forensic Medicine
  • Surgery

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