Table 3. Multivariate Cox proportional hazards regression of the training & independent validation series (stage 2 and 3 patients) using clinical factors and gene expression risk groups.

	Training series (DFS)		Training series (DSS)		Validation series (DFS)
Covariate	P-value	Hazard ratio (95% CI)	P-value	Hazard ratio (95% CI)	P-value	Hazard ratio (95% CI)
Age	0.38	0.99 (0.96–1.01)	0.38	1.01 (0.98–1.05)	0.31	0.98 (0.93–1.02)
Gender (M)	0.59	0.81 (0.38–1.74)	0.97	0.98 (0.40–2.42)	0.22	0.49 (0.16–1.52)
Grade	0.96	1.02 (0.50–2.05)	0.95	1.02 (0.43–2.43)	—	—
Stage (3)	0.07	2.04 (0.95–4.41)	0.28	1.66 (0.65–4.22	0.0021	9.23 (2.26–37.70)
Adjuvant chemotherapy	—	—			0.22	0.43 (0.12–1.62)
Adjuvant radiotherapy	—	—			0.32	3.35 (0.31–36.095)
Gene expression risk group (high risk)	0.0018	4.22 (1.72–10.39)	0.004	19.13 (2.59–141.54)	0.061	3.042 (0.96–9.69)

Abbreviations: CI=confidence interval; DFS=disease-free survival; DSS=disease-specific survival.