Table 6.

Kaplan Meier and Cox Proportional Hazards Analysis for Disease Free Survival (DFS)

		% DFS (95%CI)
Disease Free Survival (3 NAs)	1-year	68.8 (64.1 – 73.9)
	3-year	53.0 (47.8 – 58.7)
	5-year	50.3 (45.0 – 56.2)

Variable	Univariable regression		Multivariable model
	HR (95% CI)	P	HR (95% CI)	P
Age (per decade increase in age)	1.08 (0.98 – 1.19)	0.09	1.06 (0.95 – 1.18)	0.29
Depth (deep vs superficial)	2.55 (1.58 – 4.11)	<0.001 *	2.15 (1.25 – 3.68)	0.006 *
Maximal Diameter (cm)	1.06 (1.04 – 1.08)	<0.001 *	1.04 (1.02 – 1.07)	<0.001 *
Margin
Micro + vs Negative	1.68 (1.06 – 2.66)	0.03 *	1.63 (1.01 – 2.64)	0.04 *
Gross + vs Negative	1.81 (0.98 – 3.36)	0.06	1.67 (0.88 – 3.16)	0.11
Radiotherapy (yes vs no)	0.99 (0.73 – 1.34)	0.96	0.92 (0.66 – 1.27)	0.61
Chemotherapy (yes vs no)	0.96 (0.72 – 1.30)	0.81	0.87 (0.62 – 1.22)	0.42
Treating institution	n/a		n/a	0.26

(†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)