High-level expression of Hsp90 beta is associated with poor survival in resectable non-small-cell lung cancer patients

Abstract

Aims: The aim of this study was to investigate the expression of Hsp90 beta and GRP94, and elucidate the clinical significance of their expression, in patients with resectable non-small-cell lung cancer (NSCLC). Methods and results: Surgical tissue specimens were obtained from 208 patients with NSCLC who underwent surgical resection. The expression levels of Hsp90 beta and GRP94 were assessed with tissue micro-arrays and immunohistochemistry. No correlations were observed between Hsp90 beta or GRP94 expression and several clinicopathological factors. The high-Hsp90 beta group [median overall survival (OS) 20.4 months; 95% confidence interval (CI) 0.0004-0.864] showed a significant decrease in OS as compared with the low-Hsp90 beta group (median OS not reached; P = 0.003). In contrast to the Hsp90 beta analysis, the GRP94 analysis did not show a difference in OS. Moreover, in subgroup analyses of patients with squamous cell carcinoma histology, OS (P = 0.012) and relapse-free survival (P = 0.044) were significantly worse in the high-Hsp90 beta group than in the low-Hsp90 beta group. Multivariate analysis suggested that old age [hazard ratio (HR) 1.568; 95% CI 1.019-2.412; P = 0.041], advanced disease (HR 2.066; 95% CI 1.218-3.502; P = 0.007) and high Hsp90 beta expression (HR 1.802; 95% CI 1.061-3.060; P = 0.029) were independent poor prognostic factors for OS. Conclusions: Hsp90 beta expression might be a useful marker of poor OS, although further large prospective studies are warranted to validate our findings.