AR mRNA Expression and Survival Analysis

The cut-off point for the AR mRNA level was determined by a web-based calculator cut-off finder (http://molpath.charite.de/cutoff.) and median values were used as the cut-off points for other factors to categorize continuous measurements [19 (link)]. Spearman’s rank-order correlation was used to measure the association between AR mRNA expression level and clinical factors. A Kaplan–Meier product-limit estimator was used to assess RFS distribution. Log-rank tests were used to analyze differences in RFS between the high- and low-risk groups. Univariate and multivariate COX models were used to analyze factors for predicting RFS. We derived relative risks and 95% confidence intervals (95% CIs). All tests were two-sided; alpha = 0.05 was considered significant. All analyses were conducted using IBM SPSS Statistics software for Windows, version 22 (IBM Corp., Armonk, NY, USA).