Statistical Analysis
Statistical analyses were performed by a biostatistician using SPSS Statistics version 21.0 (IBM). The normality of data analyzed by using Kolmogorov-Smirnov. The descriptive statistics were reported as mean± standart deviation, medians, and ranges (min-max). Independent Sample T-Test and Mann Whitney U test, these tests are used to see there or not the average difference between the two independent groups, accordingly in parametric and nonparametric variables. The relationship between two sets of data was analyzed by Spearman’s rank correlation test. OS analyses of the groups were evaluated with Kaplan-Meier curves, and differences were tested with a log-rank test. All comparative tests were 2-tailed, and a p -value of less than 0.05 was considered to be statistically significant. Effects of covariates on possibility of survivals in univariate analysis are reported as hazard ratio (HR) with 95% confidence interval (CI).