Statistical analyses
Categorical variables were compared using χ2 tests or Fisher’s exact
tests. OS, PFS, DMFS and LRPFS were compared using the Kaplan–Meier
method with log-rank test. Cox regression analysis was used to estimate
hazard ratios (HR) and 95% confidence interval (CI). Variables with aP <0.10 in univariate analyses were included in a
multivariate analysis. Variables analyzed in our univariate analysis
study included gender (male vs female), age (<56y vs ≥56),
treatment modality (IC+CCRT vs IC+RT), smoking (no vs yes), alcohol
consumption (no vs yes), T stage (T1-2 vs T3-4), N stage (N0-2 vs N3),
overall stage (III/IVA vs IVB), modality of IC (PF/TP vs TPF), cycle of
IC treatment (≤2 vs >2), and toxicities during treatment
(<3 grade vs ≥3 grade).
The SPSS Statistics for Windows, version 24.0 (IBM, Chicago, IL), was
used for statistical analysis. All statistical tests were based on a
two-sided significance level, and P -values of <0.05,
were considered indicative of a statistically significant finding.