High-level expression of Hsp90β is associated with poor survival in resectable non-small-cell lung cancer patients

Aims: The aim of this study was to investigate theexpression of Hsp90b and GRP94, and elucidate theclinical significance of their expression, in patientswith resectable non-small-cell lung cancer (NSCLC).Methods and results: Surgical tissue specimens wereobtained from 208 patients with NSCLC who under-went surgical resection. The expression levels ofHsp90b and GRP94 were assessed with tissue micro-arrays and immunohistochemistry. No correlationswere observed between Hsp90b or GRP94 expressionand several clinicopathological factors. The high-Hsp90b group [median overall survival (OS)20.4 months; 95% confidence interval (CI) 0.000–40.864] showed a significant decrease in OS as com-pared with the low-Hsp90b group (median OS notreached; P = 0.003). In contrast to the Hsp90b analy-sis, the GRP94 analysis did not show a difference inOS. Moreover, in subgroup analyses of patients withsquamous cell carcinoma histology, OS (P = 0.012)and relapse-free survival (P = 0.044) were signifi-cantly worse in the high-Hsp90b group than in thelow-Hsp90b group. Multivariate analysis suggestedthat 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 Hsp90b expres-sion (HR 1.802; 95% CI 1.061–3.060; P = 0.029)were independent poor prognostic factors for OS.Conclusions: Hsp90b expression might be a usefulmarker of poor OS, although further large prospectivestudies are warranted to validate our findings.Keywords: GRP94, Hsp90b, non-small-cell lung cancer, prognosis