Table 3.

Cox Proportional Hazards Regression Modeling: Time to First Recurrence

Independent variable	Frequency		Univariate analysis				Multivariate reduced model
	n	%	HR	95% CI		P	HR	95% CI		P
Mutation
41A	68	51	1.03	0.45	2.37	0.9423	1.11	0.48	2.56	0.8064
45F	37	28	3.05	1.32	7.04	0.0092	3.50	1.51	8.14	0.0036
45P	9	7	1.15	0.34	3.93	0.8259	1.13	0.33	3.86	0.8499
WT (no mutation)	19	14	1.00
Gender
Female	81	61	1.29	0.78	2.14	0.3234
Male	52	39	1.00
Site
Extremity	53	40	3.52	1.24	9.95	0.0178
Superficial trunk	52	39	2.50	0.87	7.18	0.0900
Head and neck	11	8	1.50	0.34	6.72	0.5956
Deep trunk/viscera	17	13	1.00
Age at diagnosis (years)			0.98	0.96	1.00	0.0209	0.98	0.96	0.99	0.0059
Tumor size (cm)			0.95	0.90	1.02	0.1505

Cox proportional hazards univariate and multivariate reduced models. This time to recurrence analysis is from the initial surgical procedure (whether at UTMDACC or elsewhere) to the first recurrence. In the multivariate model, both mutation type and age were significant independent predictors of time to recurrence with a 3.5-fold increase in hazard among those with mutation 45T versus no mutation and a 2% decrease in hazard for each year increase in age at diagnosis. Of the 138 patients 133 were used in this cohort; 5 had missing data and were excluded. n, number of patients; HR, hazard ratio; CI, confidence interval; WT, wild type, not mutated.