Statistical analysis
Progression-free survival (PFS) and OS were the primary endpoints of the study. PFS referred to the time from the beginning of treatment to disease progression or death. OS was defined as the time of death due to any cause. Categorical variables are expressed as total numbers and percentages. Because the continuous variables are not normally distributed, median, minimum and maximum values were used as descriptive statistics. Clinical characteristics, complete remission (CR) rate, and mortality rate-related variables were compared. Categorical variables were compared using χ2 test, likelihood ratio χ2 or Fisher’s exact test, and differences in continuous variable were compared using nonparametric Mann–Whitney U-test. For the logistic proportional hazard regression models, the results were expressed as odds ratios (ORs), 95% confidence intervals (CIs) and P -values. Variables with P <.10 in univariate analysis were included in this model for multivariate analysis.P <.05 indicated statistical significance. The PFS and OS rates were estimated by Kaplan-Meier survival analysis, and the log-rank test was used for survival comparison. All tests were 2-sided. SPSS 25 was used for all statistical analyses.