Table 2.

Univariate and multivariate analysis of OS in the training set (n=1,644).

Characteristics	No. of patient	Univariate analysis		Multivariate analysis
		HR(95%CI)	P value	HR(95%CI)	P value
Gender
Male	821	Reference		Reference
Female	823	0.88(0.79–0.98)	0.023	0.86(0.77–0.96)	0.009
Age
≤37	296	Reference		Reference
38-47	988	0.89(0.77–1.03)	0.121	0.9(0.77–1.04)	0.138
≥48	360	0.91(0.77–1.09)	0.305	0.93(0.78–1.11)	0.437
Race
White	1126	Reference		–	–
Black	304	0.95(0.82–1.11)	0.528	–	–
Other	214	0.97(0.83–1.14)	0.747	–	–
Grade
Well	104	Reference		–	–
Moderately	1245	0.99(0.8–1.23)	0.936	–	–
Poorly	249	0.87(0.68–1.13)	0.307	–	–
Undifferentiated	46	1.09(0.72–1.66)	0.691	–	–
Tumor size
≤2.4cm	199	Reference		Reference
2.5-4.7cm	642	1.21(1.02–1.44)	0.03	1.39(1.11–1.73)	0.004
≤4.7cm	803	1.11(0.94–1.32)	0.217	1.28(1.02–1.62)	0.032
AJCC T stage (7th)
T1	147	Reference		Reference
T2	187	0.91(0.72–1.13)	0.386	0.77(0.59–0.99)	0.042
T3	981	0.96(0.8–1.15)	0.69	0.75(0.58–0.95)	0.02
T4a	224	0.99(0.78–1.26)	0.93	0.73(0.55–0.98)	0.039
T4b	105	1.25(0.93–1.69)	0.143	0.95(0.67–1.35)	0.792
AJCC N stage (7th)
N0	751	Reference		–	–
N1	527	1(0.88–1.13)	0.992	–	–
N2	366	1.06(0.91–1.23)	0.472	–	–
AJCC M stage (7th)
M0	1374	Reference		–	–
M1	270	1.12(0.91–1.38)	0.285	–	–
Regional nodes
Positive	858	Reference		Reference
Negative	786	0.43(0.25–0.73)	0.002	0.43(0.25–0.73)	0.002
Tumor deposits
Positive	192	Reference		Reference
Negative	1452	0.64(0.53–0.78)	<0.001*	0.67(0.55–0.82)	<0.001
Bone metastasis
Yes	2	Reference		–	–
No	1642	59959.03(0–Inf)	0.986	–	–
Liver metastasis
Yes	197	Reference		–	–
No	1447	0.94(0.74–1.2)	0.623	–	–
Lung metastasis
Yes	40	Reference		Reference
No	1604	0.42(0.24–0.75)	0.003	0.53(0.3–0.95)	0.033
Perineural invasion
Yes	248	Reference		Reference
No	1396	0.78(0.65–0.92)	0.004	0.82(0.68–0.98)	0.027

*Two-sided P values <0.05; HR, hazard ratio; CI, confidence intervals; AJCC, American Joint Committee on Cancer; TNM, tumor-node-metastasis.