Table 2. Relation between lymph node metastasis and clinical and pathological characteristics of early gastric cancer.

Factors	All T1 patients					T1a					T1b
	Patients		Lymph node metastasis			Patients		Lymph node metastasis			Patients		Lymph node metastasis
	No.	%	(−)	(+)	P-value	No.	%	(−)	(+)	P-value	No.	%	(−)	(+)	P-value
All patients	105	100	81	24		66	100	53	13		39	100	28	11
Age					0.065					0.319					0.243
⩽65	65	61.9	54	11		45	68.2	38	7		20	51.3	16	4
>65	40	38.1	27	13		21	31.8	15	6		19	48.7	12	7
Gender					0.276					0.668					0.477
Female	51	48.6	37	14		27	40.9	21	6		24	61.5	16	8
Male	54	51.4	44	10		39	59.1	32	7		15	38.5	12	3
Localization					0.357					0.345					1
Middle+Proximal	39	37.1	32	7		24	36.4	21	3		15	38.5	11	4
Distal	66	62.9	49	17		42	63.6	32	10		24	61.5	17	7
Diameter					0.049					0.105					0.482
⩽ 2 cm	66	62.8	55	11		44	66.7	38	6		22	56.4	17	5
>2 cm	39	37.2	26	13		22	33.3	15	7		17	43.6	11	6
Differentiation					0.039					0.095					0.471
Well+Moderately	50	47.6	43	7		34	51.5	30	4		16	41	13	3
Poorly	55	52.4	38	17		32	48.5	23	9		23	59	15	8
Intravascular tumor thrombi					0.028					0.337					0.042
No	93	88.6	75	18		60	90.9	49	11		33	84.6	26	7
Yes	12	11.4	6	6		6	9.1	4	2		6	15.4	2	4
Lauren classification					0.622					0.731					0.767
Intestinal type	70	66.7	53	17		43	65.2	34	9		27	69.2	19	8
Diffuse+Mixed type	35	33.3	28	7		23	34.8	19	4		12	30.8	9	3
OLFM4 expression					<0.001					0.01					0.027
Low	32	30.5	17	15		16	24.2	9	7		16	41	8	8
High	73	69.5	64	9		50	75.8	44	6		23	59	20	3

Abbreviations: TNM, tumor node metastasis; T1a, tumor does not reach submucosa; T1b, tumor infiltrates to submucosa. P-value<0.05 marked in bold font shows statistical significance