Table 1.

Predictors for recurrence within 5 years (n = 280)

	Univariate Cox regression			Multivariable Cox regression
	HR	95% CI	p value	HR	95% CI	p value
Male sex	0.99	0.49–2.00	0.976
Age (years)
< 40	Ref	Ref	Ref
41–50	0.72	0.18–2.88	0.639
51–60	0.86	0.23–3.26	0.826
61–70	1.06	0.30–3.74	0.923
> 70	0.20	0.02–1.95	0.167
Tumor location
Head	Ref	Ref	Ref
Body	0.86	0.36–2.05	0.738
Tail	0.85	0.37–1.97	0.704
Tumor size (mm)
< 20	Ref	Ref	Ref
21–40	2.45	0.84–7.16	0.102
> 41	6.13	2.24–16.75	<0.001	2.27	1.10–4.72	0.027
R1 resection	1.72	0.71–4.19	0.233
WHO tumor grade	0.24	0.12–0.47	<0.001	–	–	–
Ki67 (%)
0–2	Ref	Ref	Ref
3–5	1.99	0.72–5.52	0.188
6–10	5.88	2.46–14.05	<0.001
11–20	7.68	2.52–23.42	<0.001
Ki67 > 5%	5.54	2.68–11.43	<0.001	5.21	1.47–18.4	0.010
Positive lymph nodes	4.95	2.32–10.58	<0.001	3.36	1.48–7.61	0.004
Perineural invasion	3.17	1.41–7.17	0.005	–	–	–
Vascular invasion	3.09	1.50–6.37	0.002	–	–	–

HR hazard ratio, CI confidence interval, WHO World Health Organization