Table 2. Univariable Cox regression analysis of clinical parameters and biomarkers risk score.

Predictors	Test set (n=282, events=122)			Internal validation 9999 bootstrap samples			External validation (n=135, events=80)
	HR (95% CI)	P-value	Ca	HR (95% CI)	P-value	Ca	HR (95% CI)	P-value	Ca
Age	1.00 (0.98, 1.01)	0.84	0.51	1.00 (0.98, 1.01)	0.84	0.49b	0.99 (0.97, 1.01)	0.37	0.54
Gender	1.28 (0.84, 1.97)	0.25	0.52	1.29 (0.85, 2.04)	0.26	0.52b	1.00 (0.64, 1.57)	0.99	0.50
Histology grade	1.58 (1.19, 2.11)	0.002	0.56	1.59 (1.2, 2.11)	0.001	0.56b	1.17 (0.80, 1.71)	0.41	0.54
Nodal status	2.61 (1.68, 4.07)	<0.001	0.59	2.64 (1.71, 4.35)	<0.001	0.59b	1.76 (1.13, 2.73)	0.01	0.60
Tumor stage	1.73 (1.12, 2.67)	0.01	0.55	1.75 (1.14, 2.82)	0.02	0.54b	1.48 (0.91, 2.41)	0.12	0.56
Clinical stage	1.77 (0.95, 3.3)	0.07	0.53	1.79 (1, 3.91)	0.10	0.53b	1.40 (0.90, 2.19)	0.14	0.57
Biomarker signature score	1.11 (1.08, 1.13)	< 0.001	0.69	1.11 (1.08, 1.14)	<0.001	0.69b	1.06 (1.01, 1.12)	0.02	0.59

Abbreviations: CI, confidence interval; HR, hazard ratio.

^ac-Statistics.

^bOptimism-corrected index.