Expression of γ-tubulin in non-small cell lung cancer and effect on patient survival

Abstract

Introduction. It has been reported that overexpression and altered compartmentalization of γtubulin may contribute to tumorigenesis and tumor aggressiveness in a variety of human malignancies. We have shown that γ-tubulin expression and cellular distribution pattern is also altered in non-small cell lung cancer (NSCLC) (Histol. Histopathol. 2012; 27: 1183- 1194). In the present study we examined the relationship between γ-tubulin expression and patient overall survival (OS). Material and methods. Immunohistochemistry was performed, with well-characterized anti-γ-tubulin antibodies, on 109 formalin-fixed, paraffin-embedded NSCLC specimens (p-TNM stage IIII). γ-Tubulin labeling indexes (LIs) were determined, and the association of γ-tubulin expression with clinicopathological parameters was evaluated. To analyze OS rates according to γ-tubulin LIs, patients were categorized into three groups: those with low (0- 30%), intermediate (31-69%) or high (70-100%) γtubulin LI. Association of clinicopathological parameters and γ-tubulin with survival were examined using univariate and multivariate Cox regression analysis. Results. No statistically significant association was seen between γ-tubulin overexpression and histological type, tumor differentiation, p-TNM stage and adenocarcinoma subtyping. Longer survival was observed in the high γtubulin LI group of patients with p-TNM stages II+III when compared to intermediate or low γ-tubulin LI groups, but the difference was not statistically significant (p=0.066). On the other hand, when combined low and intermediate γ-tubulin LI groups (p-TNM stages II+III) where compared to high γ-tubulin LI group, statistically significant longer survival was observed in high γtubulin group (p=0.021). Conclusion. Our findings suggest that level of γ-tubulin expression may have an impact on patient survival at more advanced NSCLC stages.