Table 2.

Summary of Important Prognostic Factors in Multivariate Analysis

	The Original Unmatched Cohort		The Propensity-Matched Cohort
Hazard Ratio (95% CI)	P*	Hazard Ratio (95% CI)	P†
FFS
IC + IMRT vs IMRT + CC	0.99 (0.61-1.61)	.963	0.82 (0.44-1.52)	.522
Age (continuous)	1.00 (0.98-1.02)	.940	1.01 (0.98-1.04)	.488
Sex	0.92 (0.56-1.49)	.730	1.04 (0.52-2.06)	.911
Histology	0.50 (0.23-1.11)	.089	1.69 (0.20-14.09)	.628
T stage	1.65 (1.27-2.14)	< .001	1.83 (1.24-2.69)	.002
N stage	1.49 (1.12-1.98)	.006	1.62 (0.94-2.79)	.081
OS
IC + IMRT versus IMRT + CC	0.90 (0.46-1.75)	.746	0.86 (0.39-1.89)	.700
Age (continuous)	1.03 (1.00-1.05)	.064	1.03 (0.99-1.07)	.113
Sex	0.82 (0.42-1.62)	.575	0.83 (0.34-1.99)	.671
Histology	0.58 (0.21-1.64)	.306	–	–
T stage	2.06 (1.40-3.03)	< .001	2.75 (1.59-4.76)	< .001
N stage	2.00 (1.37-2.90)	< .001	2.25 (1.22-4.16)	.009
DMFS
IC + IMRT versus IMRT + CC	1.09 (0.60-2.00)	.776	0.85 (0.40-1.82)	.672
Age (continuous)	1.00 (0.97-1.02)	.690	0.99 (0.96-1.03)	.741
Sex	0.81 (0.43-1.50)	.499	1.16 (0.52-2.60)	.724
Histology	0.48 (0.19-1.24)	.129	–	–
T stage	1.67 (1.21-2.31)	.002	2.22 (1.38-3.57)	.001
N stage	1.90 (1.36-2.64)	< .001	2.28 (1.21-4.31)	.011
LRFS
IC + IMRT versus IMRT + CC	1.06 (0.45-2.47)	.899	0.95 (0.30-3.00)	.936
Age (continuous)	0.99 (0.96-1.02)	.457	0.99 (0.94-1.04)	.684
Sex	0.99 (0.44-2.22)	.976	0.74 (0.19-2.96)	.671
Histology	0.51 (0.15-1.71)	.276	0.49 (0.06-3.67)	.486
T stage	1.29 (0.86-1.93)	.221	1.10 (0.64-1.89)	.727
N stage	1.31 (0.80-2.12)	.282	1.01 (0.37-2.77)	.981

^⁎Adjusted for age (continuous), sex, histology, T stage, and N stage.

^†Adjusted for the same covariates with a robust variance estimator to account for the clustering within matched pair.