Statistics for windows version 24

Statistical analysis was performed using the software package IBM SPSS (Chicago, IL) Statistics for Windows (version 24). For comparison of BUB1 and Ki-67 protein expression with clinico-pathologic parameters (gender, age, tumor stage, nodal status, metastasis status, lymphatic vessel invasion, vein invasion, resection status, grade and UICC stage) a non-parametric Spearman's rank correlation coefficient was calculated. The relation between Ki-67 expression and histologic type of GC was evaluated by Fisher's exact test. The correlation between BUB1 and Ki-67 expression was examined using Spearman's rank correlation coefficient. OS estimates were calculated according to the Kaplan-Meier method using log-rank test. Univariate and multivariate analysis were performed using Cox regression. Multivariate Cox regression analysis was run backwards with p(in) = 0.05 and p(out) = 0.1. Hazard ratios (HR) and their 95% confidence intervals (95% CI) were calculated. All tests were 2-sided, and p values <0.05 were considered statistically significant.