Overexpression of estrogen receptor beta is a prognostic marker in non-small cell lung cancer: a meta-analysis

Expression of estrogen receptor beta (ERβ) is a potentially interesting prognostic marker and therapeutic target in non-small cell lung cancer (NSCLC). Although the expression of ERβ has been reported to correlate with better prognosis of NSCLC in most literatures, some controversies still exist. Since the limited patient numbers within independent studies, here we performed a meta-analysis to clarify the correlations between ERβ expression and prognosis in NSCLC.

We performed a final analysis of 2279 patients from 14 evaluable studies for Prognostic Value of overexpression ERβ (up to October 2014). Data from eligible studies were extracted and included into meta-analysis using a random effects model. Studies were pooled. Summary hazard ratios (HR) were calculated.

Our study shows that the pooled hazard ratio (HR) of overexpression ERβ for overall survival in NSCLC was 0.78 [95% confidence interval (CI): 0.62-0.98] by univariate analysis and 1.06 (95% CI: 0.70-1.61) by multivariate analysis. Pooled HR in American and Japan was 1.09 (95% CI: 0.95-1.25, P=0.239) from 6 studies reported, however, pooled HR was 0.57 (95% CI: 0.46-0.70) outside of American and Japan from 8 studies reported. Pooled HR was 0.75 (95% CI: 0.60-0.94) from 6 studies reported for N-ERβ and 0.76 (95% CI: 0.51-1.12) from 6 Studies reported for C-ERβ.

Our results suggested ERβ was significant associated with good overall survival in patients with NSCLC on univariate analysis but not multivariate analysis. ERβ expression is a good prognostic outcome outside of American and Japan. Overexpression of N-ERβ NSCLC patients had better survival. Large prospective studies are now needed to confirm the clinical utility of ERβ as an independent prognostic marker.