Nomogram established using risk factors of early gastric cancer for predicting the lymph node metastasis

Table 2 Univariate analysis for lymph node metastasis of patients with early gastric cancer

Variables	Level	Training sets		P value	Testing sets		P value
		LNM (-)	LNM (+)		LNM (-)	LNM (+)
		n = 1308	n = 242		n = 572	n = 95
Age at diagnosis (mean ± SD)		71.07 (12.82)	68.64 (12.82)	0.0071	70.42 (12.80)	69.02 (12.03)	0.319
Race (%)	White	733 (56.0)	122 (50.4)	0.237	332 (58.0)	60 (63.2)	0.584
	Black	202 (15.4)	45 (18.6)		93 (16.3)	15 (15.8)
	Other	373 (28.5)	75 (31.0)		147 (25.7)	20 (21.1)
Gender (%)	Male	710 (54.3)	136 (56.2)	0.631	315 (55.1)	53 (55.8)	0.985
	Female	598 (45.7)	106 (43.8)		257 (44.9)	42 (44.2)
Location (%)	Body of stomach	215 (16.4)	38 (15.7)	0.239	99 (17.3)	13 (13.7)	0.444
	Gastric antrum	479 (36.6)	90 (37.2)		231 (40.4)	43 (45.3)
	Fundus of stomach	67 (5.1)	12 (5.0)		30 (5.2)	1 (1.1)
	Greater curvature of stomach	86 (6.6)	19 (7.9)		41 (7.2)	6 (6.3)
	Lesser curvature of stomach	192 (14.7)	35 (14.5)		72 (12.6)	12 (12.6)
	Stomach, NOS	51 (3.9)	10 (4.1)		13 (2.3)	4 (4.2)
	Pylorus	131 (10.0)	13 (5.4)		55 (9.6)	8 (8.4)
	Overlapping lesion of stomach	87 (6.7)	25 (10.3)		31 (5.4)	8 (8.4)
Histology type (%)	Neuroendocrine carcinoma	53 (4.1)	1 (0.4)	0.0031	27 (4.7)	0 (0.0)	0.088
	Signet ring cell carcinoma	238 (18.2)	43 (17.8)		98 (17.1)	14 (14.7)
	Adenocarcinoma	940 (71.9)	173 (71.5)		409 (71.5)	77 (81.1)
	Others/unknown	77 (5.9)	25 (10.3)		38 (6.6)	4 (4.2)
Grade (%)	Well	252 (19.3)	7 (2.9)	< 0.0011	125 (21.9)	5 (5.3)	< 0.0011
	Moderate	448 (34.3)	85 (35.1)		190 (33.2)	30 (31.6)
	Poor	608 (46.5)	150 (62.0)		257 (44.9)	60 (63.2)
Stage (%)	I	53 (4.1)	0 (0.0)	< 0.0011	27 (4.7)	0 (0.0)	< 0.0011
	IA	1250 (95.6)	0 (0.0)		543 (94.9)	0 (0.0)
	IB	5 (0.4)	166 (68.6)		2 (0.3)	59 (62.1)
	IIA	0 (0.0)	54 (22.3)		0 (0.0)	26 (27.4)
	IIB	0 (0.0)	22 (9.1)		0 (0.0)	10 (10.5)
T-stage (%)	T1/T1NOS	216 (16.5)	30 (12.4)	< 0.0011	101 (17.7)	9 (9.5)	< 0.0011
	T1a	514 (39.3)	37 (15.3)		231 (40.4)	19 (20.0)
	T1b	578 (44.2)	175 (72.3)		240 (42.0)	67 (70.5)
Tumor size (%)	0-1 cm	313 (23.9)	12 (5.0)	< 0.0011	136 (23.8)	3 (3.2)	< 0.0011
	< 2 cm	331 (25.3)	51 (21.1)		165 (28.8)	20 (21.1)
	< 3 cm	241 (18.4)	59 (24.4)		97 (17.0)	16 (16.8)
	< 4 cm	158 (12.1)	45 (18.6)		70 (12.2)	19 (20.0)
	< 5 cm	89 (6.8)	28 (11.6)		43 (7.5)	14 (14.7)
	> 5 cm and more	176 (13.5)	47 (19.4)		61 (10.7)	23 (24.2)
Primary (%)	No	268 (20.5)	34 (14.0)	0.0251	119 (20.8)	20 (21.1)	0.956
	Yes	1040 (79.5)	208 (86.0)		453 (79.2)	75 (78.9)
Order (%)	One primary only	918 (70.2)	190 (78.5)	0.146	405 (70.8)	69 (72.6)	0.332
	1st of 2 or more primaries	104 (8.0)	16 (6.6)		42 (7.3)	5 (5.3)
	2nd of 2 or more primaries	215 (16.4)	31 (12.8)		95 (16.6)	16 (16.8)
	3rd of 3 or more primaries	51 (3.9)	3 (1.2)		23 (4.0)	3 (3.2)
	4th of 4 or more primaries	14 (1.1)	2 (0.8)		6 (1.0)	1 (1.1)
	5th of 5 or more primaries	5 (0.4)	0 (0.0)		1 (0.2)	0 (0.0)
	6th of 6 or more primaries	1 (0.1)	0 (0.0)		0 (0.0)	0 (0.0)
	7th of 7 or more primaries	0 (0.0)	0 (0.0)		0 (0.0)	1 (1.1)
Marital status (%)	Married	743 (56.8)	131 (54.1)	0.444	314 (54.9)	57 (60.0)	0.431
	Divorced	80 (6.1)	15 (6.2)		47 (8.2)	11 (11.6)
	Separated	13 (1.0)	4 (1.7)		7 (1.2)	1 (1.1)
	Single	165 (12.6)	36 (14.9)		78 (13.6)	13 (13.7)
	Widowed	251 (19.2)	46 (19.0)		102 (17.8)	9 (9.5)
	Unmarried or Domestic Partner	2 (0.2)	2 (0.8)		0 (0.0)	0 (0.0)
	Unknown	54 (4.1)	8 (3.3)		24 (4.2)	4 (4.2)
Insurance (%)	Insured	784 (59.9)	149 (61.6)	0.515	345 (60.3)	52 (54.7)	0.771
	Insured/no specifics	234 (17.9)	34 (14.0)		104 (18.2)	19 (20.0)
	Any medicaid	243 (18.6)	48 (19.8)		101 (17.7)	21 (22.1)
	Uninsured	28 (2.1)	8 (3.3)		11 (1.9)	2 (2.1)
	Insurance status unknown	19 (1.5)	3 (1.2)		11 (1.9)	1 (1.1)

¹It means statistically significant.

LMN: Lymph node metastasis; EGC: Early gastric cancer.