TABLE 3.

Risk factors for three‐year disease‐free survival

			Multivariate analysis
	Univariate analysis		Model 1		Model 2, PNI
	Hazard ratio (95% CI)	p	Hazard ratio (95% CI)	p	Hazard ratio (95% CI)	p
Age	1.008 (0.983–1.033)	0.551	1.024 (0.991–1.058)	0.163	1.011 (0.988–1.035)	0.339
Sex	0.772 (0.376–1.586)	0.481	0.858 (0.339–2.175)	0.747	0.777 (0.377–1.603)	0.495
Neoadjuvant Tx.	2.037 (1.346–3.083)	0.001	0.741 (0.382–1.435)	0.373	2.436 (1.589–3.735)	< 0.001
Incomplete resection	4.467 (2.614–7.631)	< 0.001	1.167 (0.476–2.858)	0.020	2.114 (1.166–3.835)	0.014
Stage II (vs. 0 and I)	1.553 (0.937–2.573)	0.087	0.736 (0.329–1.647)	0.456	1.489 (0.896–2.474)	0.124
Stage III (vs. 0 and I)	5.736 (3.689–8.918)	< 0.001	3.860 (1.620–9.193)	0.002	4.987 (3.114–7.987)	< 0.001
Perineural invasion	4.000 (2.393–6.688)	< 0.001			1.890 (1.088–3.282)	0.024
Concordance index			0.712 (0.638–0.786)		0.723 (0.649–0.798)

Abbreviations: CI, confidence interval; PNI, perineural invasion.