Statistical analyses
Chi-square test or Fisher’s exact test were used to compare the groups. The Kaplan–Meier method and Cox proportional regression model were used to estimate the mean/median survival rates, failure rates, and hazard ratios (HRs). Log-rank test was used to compare the survival distributions between groups. The prognostic ability of ALDH1 and CD44 were evaluated for DFS in both univariate and multivariable analyses. DFS was defined as the time from diagnosis to any documented clinical progression, relapse, or death from any cause. The results were reported as mean±SD, median, number (n ) and percent (%). A p value < 0.05 was considered significant. The analyses were performed using the IBM SPSS Statistics version 22.0 (IBM Corp., Armonk, NY).