Table 1.

Patients’ demographics and clinical characteristics SEER 2004–12 (n = 2996)

Variable	All patients		Training cohort		SEER validation cohort
	No.	%	No.	%	No.	%
	2996	100	2247	75	749	25
Race
White	2352	78.5	1779	79.17	573	76.5
Black	387	12.92	282	12.55	105	14.02
Others*	257	8.58	186	8.58	71	9.48
Age
18–39	184	6.14	140	6.23	44	5.87
40–59	1245	41.46	928	41.3	317	42.32
>60	1567	52.3	1179	52.47	388	51.8
Sex
Female	1526	50.93	1134	50.47	392	52.34
Male	1470	49.07	1113	49.53	357	47.66
T
T1	40	1.34	33	1.47	7	0.93
T2	96	3.2	74	3.29	96	3.2
T3	1878	62.68	1390	61.86	488	65.15
T4	982	32.78	750	33.38	232	30.97
N
N0	527	17.59	409	18.2	118	15.75
N1	1129	37.68	843	37.52	286	38.18
N2	1340	44.73	995	44.28	345	46.06
M
M1a	711	23.73	529	23.54	182	24.3
M1b	2285	76.27	1718	76.46	567	75.7
CEA
Negative	709	23.66	540	24.03	169	22.56
Positive	2287	76.34	1707	75.97	580	77.44
Grade
Well differentiated	99	3.3	78	3.47	21	2.8
Moderately differentiated	2077	69.33	1562	69.51	515	68.76
Poorly differentiated	712	23.77	526	23.41	186	24.83
Undifferentiated	108	3.6	81	3.6	27	3.6
Histology
Other Adenocarcinoma	2681	89.49	2010	89.45	671	89.59
Mucinous adenocarcinoma	264	8.81	202	8.99	62	8.28
Signet ring cell carcinoma	51	1.7	35	1.56	16	2.14

^aIncluding American Indian or Alaska Native and Asian or Pacific Islander.