Table 3.

Correlations between clinicopathological characteristics of patients and liver metastasis in the training and validation sets

Clinicopathological variables	Training set			Validation set
	Negative	Positive	P value	Negative	Positive	P value
Age	67.07 (13.38)	63.70 (12.88)	0.494	67.24 (13.42)	62.78 (13.15)	0.481
Gender
Female	10,821	146	0.084	5464	48	0.001
Male	10,736	177		5343	84
Marriage
Married	11,881	165	0.311	5970	77	0.461
Single	8324	138		4156	50
Unknown	1352	20		681	5
Race
American Indian/Alaska Native	152	2	0.006	67	2	0.063
Asian or Pacific Islander	1634	16		803	14
Black	2600	58		1276	22
White	17,171	247		8661	94
Histological grade
Well differentiated	4124	34	< 0.001	2043	13	< 0.001
Moderately differentiated	15,394	240		7795	100
Poorly differentiated	1720	41		841	13
Undifferentiated	319	8		128	6
Histological type
Adenocarcinoma	18,632	285	0.067	9327	112	0.154
Carcinoid tumor	641	3		341	1
Neuroendocrine carcinoma	190	4		94	3
Mucinous adenocarcinoma	1054	21		501	9
Other	1040	10		544	7
T classification
T1	11,222	122	< 0.001	5631	42	< 0.001
T2	10,335	201		5176	90
Tumor size
<5 cm	16,310	164	< 0.001	8120	74	< 0.001
≥ 5 cm	2312	99		1118	36
Unknown	3115	60		1569	22
CEA
Negative	8057	54	< 0.001	4019	26	< 0.001
Borderline	53	1		25	1
Positive	2097	173		1057	58
Unknown	11,350	95		5706	47
Tumor number
1	15,001	213	0.441	7482	93	0.687
2	4904	85		2474	32
3	1242	20		646	6
> 3	410	5		205	1
Overall survival
Alive	18,646	151	< 0.001	9342	67	< 0.001
Dead	2911	172		1465	65

Italic values: differences are statistically significant

CEA, carcinoembryonic antigen