SESSION TITLE: Biomarkers in Lung Cancer
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Sunday, October 27, 2013 at 10:45 AM - 11:45 AM
PURPOSE: EGFR overexpression is observed in significant proportions of non-small cell lung carcinomas (NSCLC). Furthermore, overactivation of telomerase leads to cell immortalization during carcinogenesis. Our aim was the evaluation of EGFR gene and protein alterations in NSCLC and the potential role of telomerase in the regulation of its expression.
METHODS: Using tissue microarray technology (ATA 100), forty (n=40) paraffin embedded histologically confirmed primary NSCLCs were cored twice at a diameter of 1mm and re-embedded into a recipient block. Immunohistochemistry was performed by the use of monoclonal antibodies anti-EGFR (31G7), and anti-telomerase/h-TERT (44F12). Also, a Chromogenic in situ hybridization (CISH-SPOTLIGHT) protocol was applied based on the use of EGFR gene and chromosome 7 centromeric probes. Computerized Image Analysis was performed for the evaluation of immunohistochemistry results. Statistical analysis was based on SPSS (v 11.0)
RESULTS: EGFR overexpression was observed in 23/40 (57.5%) cases correlating to stage (p=0.001) and histological type (p=0.04). Telomerase was overexpressed in all examined cases (high and moderate levels) correlating to stage (p=0.001). A significant value of concordance (kappa=0.686, 0.677-0.695) was assessed comparing telomerase and EGFR protein expression. EGFR gene amplification was identified in 2/40 (5%) cases associating to histological type (p=0.027) and chromosome 7 aneuploidy in 7/40 (17.5%) cases.
CONCLUSIONS: NSCLC is characterized by rare cases of EGFR gene amplification and this genetic event maybe affect the efficacy of targeted therapeutic strategies based on monoclonal antibodies. Also, the strong concordance between EGFR and telomerase overexpression demonstrates that the enzyme is potentially involved in the growth-controlling gene expression.
CLINICAL IMPLICATIONS: Our combined study showed that there is a strong correlation between the activation and expression of these two genes and maybe this co-deregulation could be used as a prognostic factor for the evaluation of biological behavior in NSCLCs.
DISCLOSURE: The following authors have nothing to disclose: Athanassios Stamatelopoulos, Evangelos Tsiambas, Petros Michos, Nicolaos Antzoulatos, Ioannis Gakidis, Christos Chatziantoniou, Dimosthenes Bouros
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