Epidermal growth factor receptor (EGFR) status in different stages of resected non-small cell lung cancer (NSCLC): Implications for treatment with EGFR-targeted monoclonal antibodies

Abstract

20015 Background: Aim of our study was to verify potential changes in EGFR status in different stages of resected NSCLC. This was done in order to find out whether assessing the EGFR status could be considered an effective tool for planning therapy with EGFR-targeted monoclonal antibodies in different setting of patients. Methods: From January 1996 through December 2001, 439 patients underwent radical surgery for NSCLC at the Department of Thoracic Surgery of Università Politecnica delle Marche. EGFR expression was evaluated with an immunohistochemical technique on five micron-thick tissue sections obtained from specimens fixed in 10% (v/v) neutral buffered formalin and paraffin embedded.EGFR expression was detected as membranous and/or cytoplasmic brown staining of neoplastic cells with various intensity. Positivity for EGFR expression was defined as any membrane staining above background level. Both the primary and metastatic neoplasm were considered positive when ≥ 1% of the tumour cells had membranous staining. Results: Table 1 summarizes patients’ characteristics. Samples from 423 patients were available for EGFR analysis. EGFR immunohistochemical expression was found positive as follows: 15.8% in stage IIIB, 12.2% in IIIA, 2.3% in IIB, 5.3% in IIA, 4.8% in IB and 5% in IA. At multivariate analysis, EGFR status resulted indicator of prognosis both when considering all the patients and in the groups of patients with different stages of disease. Conclusions: Globally our findings seem to confirm the role of EGFR as a prognostic indicator in NSCLC. Furthermore the observation that EGFR is more frequently overexpressed in the advanced stages may suggest that EGFR-targeted treatment strategies could be more appropriated in this subgroup of patients. [Table: see text] No significant financial relationships to disclose.