Analysis of the prognostic impact of nestin expression in non-small cell lung cancer.

BACKGROUND Nestin is an intermediary filament protein, expressed in progenitor cells of neural and muscle origin and in activated endothelium. The expression of this protein in tumours can be associated with degree of differentiation, biological potential and/or neoangiogenesis. AIMS The aim of this study was to examine the immunohistochemical expression of nestin in primary non-small cell lung carcinomas (NSCLC) and to determine its prognostic significance. METHODS Immunohistochemical detection of nestin was carried out on tissue microarrays constructed from 114 formalin-fixed and paraffin-embedded NSCLC samples. These included 78 squamous cell carcinomas and 37 adenocarcinomas. Expression of nestin was also analysed in 35 primary tumour independent NSCLC brain metastasis. The H-score and degree of nestin positive microvascularisation were determined. Both parameters correlated with the clinicopathological characteristics including disease-free and overall survival. Results. We demonstrated that expression of nestin is not significantly higher in tumour cells of adenocarcinomas than in sqamous cell carcinomas despite the fact that adenocarcinomas were more frequently positive (P≤0.30). On the other hand, nestin positivity and nestin positive neovascularisation were significantly more often found in stage IIIa tumours than tumours in stages I and II (P≤0.04, P≤0.02). Nestin expression was also significantly higher in brain metastases of squamous cell carcinomas than brain metastases of adenocarcinomas (P≤0.003). The expression of nestin, in general, did not significantly correspond to disease-free or overall survival. CONCLUSION Nestin expression in NSCLCs is associated with poorer prognosis and with greater nestin-positive microvessel density.