Table 2.

Characteristics of patients in SEER cohort: univariate and multivariate analysis.

Characteristics	Patients	Overall Survival
		Univariate analysis	Multivariate analysis	Multivariate HR	95% Confidence interval (CI)
Total	1028
Gender		0.55	NA	0.89	0.664–1.203
Males	609
Females	419
Age (years)		0.001	0.46
15–39	68
40–59	546
60–79	336
80+	78
Differentiation		0.001	0.000	1.28	1.16–1.42
Well-differentiated	563
Moderately-differentiated	125
Poorly differentiated/undifferentiated	340
T classification		0.001	0.053	1.19	1.06–1.33
T1	527
T2	44
T3	110
T4	60
N classification		0.001	0.018	0.68	0.38–1.22
N0	216
N1	648
N2	164
M classification		0.000	0.003	0.38	0.22–0.67
M0	832
M1	196
TNM stage		0.000	0.000	1.54	1.30–1.82
I	516
II	88
III	143
IV	281
Surgery of primary site		0.001	0.000	0.43	0.30–0.62
Yes	804
No	412