Risk factors and a predictive nomogram for lymph node metastasis in superficial esophageal squamous cell carcinoma

Table 1 Patient clinicopathologic characteristics

Characteristics	No. of patients, n (%)
Gender
Male	367 (77.4)
Female	107 (22.6)
Age (yr), median (range)	60 (38-84)
Tumor size (mm), median (range)	23 (3-73)
Tumor location
Upper third	28 (5.9)
Middle third	303 (63.9)
Lower third	143 (30.2)
Paris classification
0-I	95 (20.0)
0-II	309 (65.2)
0-III	70 (14.8)
Depth of invasion
MM	152 (32.1)
SM1	80 (16.9)
SM2	106 (22.3)
SM3	136 (28.7)
Differentiation
Well	103 (21.7)
Moderate	279 (58.9)
Poor	92 (19.4)
INF pattern
INF-a	196 (41.4)
INF-b	232 (48.9)
INF-c	46 (9.7)
Tumor budding	64 (13.5)
LVI	27 (5.7)
LNM
Yes	90 (19.0)
No	384 (81.0)
Dissected LN, median (range)	18.0 (12-53)

MM: Muscularis mucosae; SM1: Upper third of submucosa; SM2: Middle third of submucosa; SM3: Lower third of submucosa; INF pattern: Infiltrative growth pattern; LVI: Lymphovascular invasion; LNM: Lymph node metastasis; LN: Lymph node.

Table 2 Comparisons of clinicopathological characteristics between lymph node metastasis positive and lymph node metastasis negative group

Variable	Training set (n = 332)		P value	Validation set (n = 142)		P value
	LNM(-)	LNM(+)		LNM(-)	LNM(+)
Gender			0.298			0.913
Male	201	51		84	20
Female	68	12		31	7
Age (yr), median (range)	60 (42-80)	60 (45-84)	0.204	60 (38-78)	58 (47-76)	0.522
Tumor size, (cm), mean ± SD	2.23 ± 1.21	2.65 ± 0.99	0.008	2.07 ± 0.97	2.61 ± 0.86	0.008
Tumor location, n (%)			0.095			0.702
Upper third	14	6		7	1
Middle third	181	47		62	13
Lower third	74	10		46	13
Paris classification, n (%)			0.282			0.158
0-I	46	14		26	9
0-II	186	37		74	12
0-III	37	12		15	6
Depth of invasion, n (%)			< 0.001			< 0.001
MM	100	3		47	2
SM1	53	6		19	2
> SM1	116	54		49	23
Differentiation, n (%)			0.015			0.029
Well	77	8		15	3
Moderate	148	38		80	13
Poor	44	17		20	11
INF pattern, n (%)			0.001			0.014
INF-a	125	13		53	5
INF-b	123	41		52	16
INF-c	21	9		10	6
Tumor budding, n (%)			0.009			0.009
No	241	48		103	18
Low	19	8		8	5
High	9	7		4	4
LVI, n (%)			0.005			0.004
Yes	10	8		4	5
No	259	55		111	22

LNM: Lymph node metastasis; MM: Muscularis mucosae; SM1: Upper third of submucosa; INF pattern: Infiltrative growth pattern; LVI: Lymphovascular invasion.

Table 3 Multivariate logistic analysis of risk factors for lymph node metastasis in superficial esophageal squamous cell carcinoma

Factors	Training set			Validation set
	OR	95%CI	P value	OR	95%CI	P value
Tumor size (cm)	1.365	1.081-1.723	0.009	1.750	1.139-2.688	0.011
Invasive depth
MM	Reference			Reference
SM1	3.774	0.907-15.696	0.068	2.474	0.325-18.856	0.382
> SM1	15.517	4.707-51.158	0.001	11.031	2.463-49.401	0.002
Tumor differentiation
Well or cis	Reference			Reference
Moderate	2.423	0.807-9.451	0.072	0.715	0.179-2.856	0.635
Poor	3.670	1.465-9.198	0.006	4.078	0.977-17.026	0.054
INF pattern
INF-a	Reference			Reference
INF-b	3.205	1.637-6.274	0.001	3.262	1.114-9.552	0.031
INF-c	4.121	1.566-10.843	0.004	6.360	1.623-24.922	0.008
Tumor budding
Low	2.114	0.875-5.108	0.096	3.815	0.978-14.813	0.054
High	3.905	1.387-10.995	0.010	4.769	1.315-17.290	0.017
No	Reference			Reference
LVI
No	Reference			Reference
Yes	3.767	1.422-9.979	0.008	4.408	1.346-14.438	0.014

MM: Muscularis mucosae; SM1: Upper third of submucosa; INF pattern: Infiltrative growth pattern; LVI: Lymphovascular invasion.