Are heterogenous results of EGFR immunoreactivity in renal cell carcinoma related to non-standardised criteria for staining evaluation?
- 1Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, A-8036 Graz, Austria
- 2Department of Surgery, Division of Biomedical Engineering and Computing, Medical University of Graz
- 3Department of Urology, Medical University of Graz
- Correspondence to: Dr C Langner Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, A-8036 Graz, Austria; cord.langnermeduni-graz.at
- Accepted 12 February 2004
Abstract
Aims: To assess whether heterogeneity of epidermal growth factor receptor (EGFR) immunoreactivity in renal cell carcinoma (RCC) is related to non-standardised criteria for staining evaluation.
Methods: EGFR expression was investigated in 132 primary and 55 metastatic conventional RCCs using a tissue microarray technique.
Results: Overall, membranous and/or cytoplasmic EGFR immunostaining was present in 123 of 132 (93%) primary and 49 of 53 (92%) metastatic RCCs, with extensive immunoreactivity (> 50% of tumour cells) in 110 of 132 (83%) primary tumours and 39 of 53 (73%) metastases. Cytoplasmic staining was associated with high tumour stage and high tumour grade. In addition, strong membranous staining (score 3+) prevailed in high grade RCCs. Cytoplasmic immunostaining was associated with an unfavourable prognosis, whereas overall (cytoplasmic and membranous) immunoreactivity and intensity of membranous staining were not.
Conclusions: Different methods of immunohistochemical evaluation led to different results, strengthening the need for standardisation, especially against a background of rapidly evolving EGFR targeted cancer treatment strategies.
- renal cell carcinoma
- epidermal growth factor receptor
- immunohistochemical evaluation
- prognosis
- treatment
