rss
J Clin Pathol 2006;59:585-590 doi:10.1136/jcp.2005.028373
  • Original article

Pitfalls in immunohistochemical assessment of EGFR expression in soft tissue sarcomas

  1. C Kersting1,
  2. J Packeisen1,
  3. B Leidinger2,
  4. B Brandt3,
  5. R von Wasielewski4,
  6. W Winkelmann2,
  7. P J van Diest5,
  8. G Gosheger2,
  9. H Buerger1
  1. 1Institute of Pathology, University of Münster, Münster, Germany
  2. 2Department of Orthopaedic Surgery, University of Münster
  3. 3Institute of Clinical Chemistry and Laboratory Medicine, University of Münster
  4. 4Institute of Pathology, Medizinische Hochschule Hannover, Hannover, Germany
  5. 5Department of Pathology, University Medical Centre Utrecht, Utrecht, Netherlands
  1. Correspondence to:
    Dr Horst Bürger
    Institute of Pathology, Westfälische Wilhelmsuniversität Münster, Domagkstraße 17, 48149 Münster, Germany; burgerh{at}uni-muenster.de
  • Accepted 28 June 2005
  • Published Online First 3 February 2006

Abstract

Background: New targeted cancer treatments acting against growth factor receptors such as the epidermal growth factor receptor (EGFR) necessitate selecting patients for treatment with these drugs. Besides carcinomas, soft tissue sarcomas (STS) express EGFR and might thereby be a promising target for this new therapeutic strategy.

Objective: To test and compare different EGFR antibodies to determine the frequency of EGFR expression in STS.

Methods: 302 consecutive specimens of STS were examined using the tissue microarray technique. EGFR expression levels were assessed by immunohistochemistry using five different commercially available antibodies. Gene amplification status was measured by fluorescence in situ hybridisation (FISH). Immunoreactivity and amplification status were correlated with clinicopathological features and follow up data available in 163 cases.

Results: EGFR expression frequency ranged between 0.3% and 52.9%, depending on the antibody and scoring method used. In all, 3.5% of the tumours showed egfr gene amplification by FISH, which correlated with EGFR expression for three antibodies. Only one antibody had independent prognostic value in multivariate analysis and correlated with an unfavourable outcome; egfr gene amplification status showed no correlation with clinical features.

Conclusions: Frequency of EGFR immunopositivity in STS strongly depends on the antibody used, and only one of five antibodies tested predicted an unfavourable clinical outcome. This indicates that choice of primary antibody and scoring system have a substantial impact on the determination of EGFR immunoreactivity.

Footnotes

    Register for free content

    The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.