Table 4.

Cox Proportional Hazards Regression Modeling: Time to First Recurrence Primaries Treated at UTMDACC Only

Independent variable	Frequency		Univariate analysis				Multivariate reduced model
	n	%	HR	95% CI		P	HR	95% CI		P
Mutation
45F	19	22	4.28	1.75	10.48	0.0015	4.28	1.75	10.48	0.0015
Not 45F	69	78	1.00				1.00
Gender
Female	52	59	1.15	0.47	2.82	0.7559
Male	36	41	1.00
Site
Extremity	31	35	5.87	0.76	45.52	0.0905
Superficial trunk	33	37	2.99	0.36	24.87	0.3117
Head and neck	10	11	3.60	0.32	39.82	0.2969
Deep trunk/viscera	14	16	1.00
Age at diagnosis (years)	88	100	0.98	0.95	1.01	0.1596
Tumor size (cm)	75	100	0.98	0.89	1.07	0.6564
Margins
Positive	36	44	2.33	0.92	5.93	0.0755
Negative	46	56	1.00

Cox proportional hazards univariate and multivariate reduced models including only the 89 primaries treated surgically at UTMDACC. In this model, the status of margins (as determined by histopathological examination) was included and all patients were known to be treated surgically with intent for complete resection. Approximately 20% of patients were treated with adjuvant radiation therapy. Neither radiation therapy nor margin status was associated with mutation type on contingency analysis (data not shown). Although site and margins showed trends towards a significant relationship with recurrence, only mutational type was significantly related in both the univariate and reduced multivariate models. n, number of patients; HR, hazard ratio; CI, confidence interval; WT, wild type, not mutated.