1.6 Data Analysis
Data were analyzed by SPSS 24.0 statistical software (IBM Corporation, Armonk, NY, USA). 95% confidence intervals (CIs) were calculated for means and percentages. Curves of PFS, DMFS, LNRFS, LRFS, NRF and OS were estimated with the Kaplan–Meier method (GraphPad Prism 8.0.1). Group frequency data were examined using Chi-squared tests. Multivariate Cox regression analysis and Log-rank tests were used for survival correlation factors and inter-group curve comparisons, respectively.