Immunohistochemical detection of EGFR in paraffin-embedded tumor tissues: variation in staining intensity due to choice of fixative and storage time of tissue sections.

Author(s): Atkins D, Reiffen K A, Tegtmeier C L, Winther H, Bonato M S, Storkel S

Publication: J Histochem Cytochem, 2004, Vol. 52, Page 893

PubMed ID: 15208356 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this paper was to assess the effects of fixative type and duration (4-48 h) on EGFR immunoreactivity in non-small-cell lung, head and neck, and colorectal cancer.

   Summary of Findings:

   While the most robust EGFR staining was observed with samples fixed for 24 hours in 4% unbuffered formalin or acetic formalin alcohol (AFA), or for 4 hours in Pen-fix, differences among fixatives were not statistically significant. Non-specific staining, while observed, was independent of fixative type. Prefer-fixed specimens alone resulted in inadequate preservation of morphology and antigenicity.

   Biospecimens

   • Tissue - Head and Neck
   • Tissue - Colorectal
   • Tissue - Lung

   Preservative Types

   • Formalin
   • Other Preservative

   Diagnoses:

   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Protein	Immunohistochemistry

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Preservation	Time in fixative	4 h 24 h 48 h
   Storage	Storage duration	<3 months
   Biospecimen Acquisition	Biospecimen location	Colorectal cancer Non-small-cell lung cancer Head and neck cancer
   Biospecimen Preservation	Type of fixation/preservation	Acetic formalin alcohol Bouin's fixative Formalin (buffered) Pen-fix Prefer Formalin (unbuffered)

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2. Study Purpose

   The purpose of this study was to assess the impact of storage (up to 24 months) of unstained paraffin-embedded sections that were differentially fixed on EGFR immunoreactivity in head/neck and colon specimens.

   Summary of Findings:

   EGFR antigenicity was significantly impacted by storage of unstained paraffin-embedded tissue sections (in the dark at room temperature) in a fixative-dependent manner. The incidence of positive immunostaining was significantly lower after 9 months of storage for Pen-fix, and 12 months of storage for AFA, 4% unbuffered or neutral buffered formalin fixed specimens. Statistical significance was limited to colon specimens.

   Biospecimens

   • Tissue - Head and Neck
   • Tissue - Colorectal

   Preservative Types

   • Formalin
   • Other Preservative

   Diagnoses:

   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Protein	Immunohistochemistry

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Preservation	Type of fixation/preservation	Acetic formalin alcohol Pen-fix 4% Unbuffered formalin 4% Neutral buffered formalin
   Storage	Storage duration	<3 months 6 months 9 months 12 months 18 months 24 months
   Biospecimen Preservation	Time in fixative	4 h 24 h

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