2.3. Statistical Analysis

The distributions of the categorical variables are described by counts and frequencies or by median and range, whereas those of continuous and count variables are described by median and interquartile range. PFS was defined as the time between the date of the beginning of docetaxel and the date of progression. OS was defined as the time between the date of the starting of docetaxel and the date of death or last follow-up.

Univariate and multivariate hazard ratios for selected potential predictors of PFS and OS were performed using a Cox proportional hazards regression model. PFS and OS were estimated using the Kaplan–Meier method. p < 0.05 was considered as significant for all analyses. All statistical analyses were performed using SPSS version 24.