Standardisation of EGFR FISH in colorectal cancer

Results of an international interlaboratory reproducibility ring study

Andrea Sartore-Bianchi, Steffen Fieuws, Silvio Veronese, Mauro Moroni, Nicola Personeni, Milo Frattini, Valter Torri, Federico Cappuzzo, Sara Vander Borght, Vittoria Martin, Margaret Skokan, Armando Santoro, Marcello Gambacorta, Sabine Tejpar, Marileila Varella-Garcia, Salvatore Siena

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Aims: Epidermal growth factor receptor (EGFR) gene copy number evaluated by fluorescence in situ hybridisation (FISH) can discriminate among KRAS wild-type patients those with better outcome to EGFR-targeted therapy in metastatic colorectal cancer, further enhancing selection of patients. Nevertheless, enumeration of gene copies is challenging and the lack of analytical standardisation has limited incorporation of the test into the clinical practice. We therefore assessed EGFR FISH interlaboratory consensus among five molecular diagnostic reference centres. Methods: A set of 12 colorectal cancer samples circulated among laboratories, and samples were scored according to commonly agreed guidelines. Reproducibility was quantified using the standard error of measurement (SEM). Results: A SEM of 0.865 and a within-subject coefficient of variation (WSCV) of 26.8% for mean EGFR gene/nuclei and a SEM of 0.235 and a WSCV of 19.4% for the mean EGFR gene/CEP7 ratio were observed. Measurement of the fraction of cells displaying chromosome 7 polysomy showed WSCV of 46.6%, 34.0% and 51.0% for percentage of cells displaying ≤2, ≥3 and ≥4 EGFR signals, respectively. Among different slides of the same specimen, the WSCV was 6.1% for mean EGFR gene/ nuclei and 3.9% for mean of EGFR gene/CEP7 ratios. Conclusions: Molecular diagnosis of EGFR gene copy number by FISH varied largely among pathology centres, with fluctuations covering the whole range of proposed cut-offs of predictive usefulness from literature. Definition of a detailed scoring system and implementation of comprehensive training programmes for laboratories are therefore necessary before including the test into clinical practice.

Original languageEnglish
Pages (from-to)218-223
Number of pages6
JournalJournal of Clinical Pathology
Volume65
Issue number3
DOIs
Publication statusPublished - Mar 2012

Fingerprint

erbB-1 Genes
Fluorescence In Situ Hybridization
Epidermal Growth Factor Receptor
Colorectal Neoplasms
Gene Dosage
Chromosomes, Human, Pair 7
Molecular Pathology
Patient Selection
Guidelines
Pathology
Education
Genes

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Cite this

Standardisation of EGFR FISH in colorectal cancer : Results of an international interlaboratory reproducibility ring study. / Sartore-Bianchi, Andrea; Fieuws, Steffen; Veronese, Silvio; Moroni, Mauro; Personeni, Nicola; Frattini, Milo; Torri, Valter; Cappuzzo, Federico; Vander Borght, Sara; Martin, Vittoria; Skokan, Margaret; Santoro, Armando; Gambacorta, Marcello; Tejpar, Sabine; Varella-Garcia, Marileila; Siena, Salvatore.

In: Journal of Clinical Pathology, Vol. 65, No. 3, 03.2012, p. 218-223.

Research output: Contribution to journalArticle

Sartore-Bianchi, A, Fieuws, S, Veronese, S, Moroni, M, Personeni, N, Frattini, M, Torri, V, Cappuzzo, F, Vander Borght, S, Martin, V, Skokan, M, Santoro, A, Gambacorta, M, Tejpar, S, Varella-Garcia, M & Siena, S 2012, 'Standardisation of EGFR FISH in colorectal cancer: Results of an international interlaboratory reproducibility ring study', Journal of Clinical Pathology, vol. 65, no. 3, pp. 218-223. https://doi.org/10.1136/jclinpath-2011-200353
Sartore-Bianchi, Andrea ; Fieuws, Steffen ; Veronese, Silvio ; Moroni, Mauro ; Personeni, Nicola ; Frattini, Milo ; Torri, Valter ; Cappuzzo, Federico ; Vander Borght, Sara ; Martin, Vittoria ; Skokan, Margaret ; Santoro, Armando ; Gambacorta, Marcello ; Tejpar, Sabine ; Varella-Garcia, Marileila ; Siena, Salvatore. / Standardisation of EGFR FISH in colorectal cancer : Results of an international interlaboratory reproducibility ring study. In: Journal of Clinical Pathology. 2012 ; Vol. 65, No. 3. pp. 218-223.
@article{7e625092a84d48e3adae40502277b936,
title = "Standardisation of EGFR FISH in colorectal cancer: Results of an international interlaboratory reproducibility ring study",
abstract = "Aims: Epidermal growth factor receptor (EGFR) gene copy number evaluated by fluorescence in situ hybridisation (FISH) can discriminate among KRAS wild-type patients those with better outcome to EGFR-targeted therapy in metastatic colorectal cancer, further enhancing selection of patients. Nevertheless, enumeration of gene copies is challenging and the lack of analytical standardisation has limited incorporation of the test into the clinical practice. We therefore assessed EGFR FISH interlaboratory consensus among five molecular diagnostic reference centres. Methods: A set of 12 colorectal cancer samples circulated among laboratories, and samples were scored according to commonly agreed guidelines. Reproducibility was quantified using the standard error of measurement (SEM). Results: A SEM of 0.865 and a within-subject coefficient of variation (WSCV) of 26.8{\%} for mean EGFR gene/nuclei and a SEM of 0.235 and a WSCV of 19.4{\%} for the mean EGFR gene/CEP7 ratio were observed. Measurement of the fraction of cells displaying chromosome 7 polysomy showed WSCV of 46.6{\%}, 34.0{\%} and 51.0{\%} for percentage of cells displaying ≤2, ≥3 and ≥4 EGFR signals, respectively. Among different slides of the same specimen, the WSCV was 6.1{\%} for mean EGFR gene/ nuclei and 3.9{\%} for mean of EGFR gene/CEP7 ratios. Conclusions: Molecular diagnosis of EGFR gene copy number by FISH varied largely among pathology centres, with fluctuations covering the whole range of proposed cut-offs of predictive usefulness from literature. Definition of a detailed scoring system and implementation of comprehensive training programmes for laboratories are therefore necessary before including the test into clinical practice.",
author = "Andrea Sartore-Bianchi and Steffen Fieuws and Silvio Veronese and Mauro Moroni and Nicola Personeni and Milo Frattini and Valter Torri and Federico Cappuzzo and {Vander Borght}, Sara and Vittoria Martin and Margaret Skokan and Armando Santoro and Marcello Gambacorta and Sabine Tejpar and Marileila Varella-Garcia and Salvatore Siena",
year = "2012",
month = "3",
doi = "10.1136/jclinpath-2011-200353",
language = "English",
volume = "65",
pages = "218--223",
journal = "Journal of Clinical Pathology - Clinical Molecular Pathology",
issn = "0021-9746",
publisher = "BMJ Publishing Group",
number = "3",

}

TY - JOUR

T1 - Standardisation of EGFR FISH in colorectal cancer

T2 - Results of an international interlaboratory reproducibility ring study

AU - Sartore-Bianchi, Andrea

AU - Fieuws, Steffen

AU - Veronese, Silvio

AU - Moroni, Mauro

AU - Personeni, Nicola

AU - Frattini, Milo

AU - Torri, Valter

AU - Cappuzzo, Federico

AU - Vander Borght, Sara

AU - Martin, Vittoria

AU - Skokan, Margaret

AU - Santoro, Armando

AU - Gambacorta, Marcello

AU - Tejpar, Sabine

AU - Varella-Garcia, Marileila

AU - Siena, Salvatore

PY - 2012/3

Y1 - 2012/3

N2 - Aims: Epidermal growth factor receptor (EGFR) gene copy number evaluated by fluorescence in situ hybridisation (FISH) can discriminate among KRAS wild-type patients those with better outcome to EGFR-targeted therapy in metastatic colorectal cancer, further enhancing selection of patients. Nevertheless, enumeration of gene copies is challenging and the lack of analytical standardisation has limited incorporation of the test into the clinical practice. We therefore assessed EGFR FISH interlaboratory consensus among five molecular diagnostic reference centres. Methods: A set of 12 colorectal cancer samples circulated among laboratories, and samples were scored according to commonly agreed guidelines. Reproducibility was quantified using the standard error of measurement (SEM). Results: A SEM of 0.865 and a within-subject coefficient of variation (WSCV) of 26.8% for mean EGFR gene/nuclei and a SEM of 0.235 and a WSCV of 19.4% for the mean EGFR gene/CEP7 ratio were observed. Measurement of the fraction of cells displaying chromosome 7 polysomy showed WSCV of 46.6%, 34.0% and 51.0% for percentage of cells displaying ≤2, ≥3 and ≥4 EGFR signals, respectively. Among different slides of the same specimen, the WSCV was 6.1% for mean EGFR gene/ nuclei and 3.9% for mean of EGFR gene/CEP7 ratios. Conclusions: Molecular diagnosis of EGFR gene copy number by FISH varied largely among pathology centres, with fluctuations covering the whole range of proposed cut-offs of predictive usefulness from literature. Definition of a detailed scoring system and implementation of comprehensive training programmes for laboratories are therefore necessary before including the test into clinical practice.

AB - Aims: Epidermal growth factor receptor (EGFR) gene copy number evaluated by fluorescence in situ hybridisation (FISH) can discriminate among KRAS wild-type patients those with better outcome to EGFR-targeted therapy in metastatic colorectal cancer, further enhancing selection of patients. Nevertheless, enumeration of gene copies is challenging and the lack of analytical standardisation has limited incorporation of the test into the clinical practice. We therefore assessed EGFR FISH interlaboratory consensus among five molecular diagnostic reference centres. Methods: A set of 12 colorectal cancer samples circulated among laboratories, and samples were scored according to commonly agreed guidelines. Reproducibility was quantified using the standard error of measurement (SEM). Results: A SEM of 0.865 and a within-subject coefficient of variation (WSCV) of 26.8% for mean EGFR gene/nuclei and a SEM of 0.235 and a WSCV of 19.4% for the mean EGFR gene/CEP7 ratio were observed. Measurement of the fraction of cells displaying chromosome 7 polysomy showed WSCV of 46.6%, 34.0% and 51.0% for percentage of cells displaying ≤2, ≥3 and ≥4 EGFR signals, respectively. Among different slides of the same specimen, the WSCV was 6.1% for mean EGFR gene/ nuclei and 3.9% for mean of EGFR gene/CEP7 ratios. Conclusions: Molecular diagnosis of EGFR gene copy number by FISH varied largely among pathology centres, with fluctuations covering the whole range of proposed cut-offs of predictive usefulness from literature. Definition of a detailed scoring system and implementation of comprehensive training programmes for laboratories are therefore necessary before including the test into clinical practice.

UR - http://www.scopus.com/inward/record.url?scp=84857366043&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84857366043&partnerID=8YFLogxK

U2 - 10.1136/jclinpath-2011-200353

DO - 10.1136/jclinpath-2011-200353

M3 - Article

VL - 65

SP - 218

EP - 223

JO - Journal of Clinical Pathology - Clinical Molecular Pathology

JF - Journal of Clinical Pathology - Clinical Molecular Pathology

SN - 0021-9746

IS - 3

ER -