Table 4.

Cox proportional hazards multiple regression analyses for outcome of systemic recurrence

Variable	Univariable regression		Multivariable model
	HR (95% CI)	P	HR (95% CI)	P
Age (per decade increase in age)	1.13 (1.02 – 1.26)	0.02 *	1.09 (0.96 – 1.23)	0.18
Depth (deep vs superficial)	3.00 (1.69 – 5.31)	<0.001 *	2.42 (1.28 – 4.60)	0.007 *
Maximal Diameter (cm)	1.06 (1.04 – 1.08)	<0.001 *	1.05 (1.02 – 1.07)	<0.001 *
Margin
Micro + vs Negative	1.32 (0.76 – 2.30)	0.33	1.22 (0.69 – 2.16)	0.50
Gross + vs Negative	1.54 (0.75 – 3.17)	0.24	1.48 (0.71 – 3.08)	0.30
Radiotherapy (yes vs no)	1.15 (0.82 – 1.61)	0.41	1.05 (0.74 – 1.50)	0.79
Chemotherapy (yes vs no)	0.98 (0.70 – 1.37)	0.90	0.86 (0.60 – 1.26)	0.45
†† Treating Institution	n/a	0.11	-	-

(†Variables in model selected based on a priori determination (CT and RT) and univariable cox analysis with p<0.10)

(†† Controlling for random effects of treating institution)

(n=343, 27 observations deleted due to missingness)