Statistical analysis
Data are presented as mean (SD) when normally distributed or as median with 25th and 75th percentiles (interquartile range [IQR]) when normality assumptions (the Shapiro-Wilk test) were not met. Categorical data are expressed as a number and percentage. Kaplan–Meier time-to-event curves were generated for the entire cohort and the subgroups were compared with the log-rank (Mantel–Cox) test. The five year survival with standard error was estimated for both groups. GraphPad Prism 8.2.0 (GraphPad Software, San Diego, California, United States) was used for all statistical analysis, except the Cox analysis which was done with IBM SPSS Statistics for Windows, version 22 (IBM Corp. Armonk, New York, United States).