Table 3. Correlations between risk factors and the incidence of number 3b lymph node metastasis.

Variables		Total	Number 3b metastasis-positive	Incidence of Number 3b metastasis	P value
Sex					0.264
	Male	37	4	10.8%
	Female	14	0	0.0%
Age (years)					0.617
	≥65	28	2	7.1%
	<65	23	2	8.7%
Macroscopic type					0.300
	Type 0–2	37	2	5.4%
	Type 3, 4, and 5	14	2	14.3%
T stage					0.653
	T1	5	0	0.0%
	T2, T3, and T4	46	4	8.7%
Siewert type					0.120
	II	33	1	3.0%
	III	18	3	16.7%
Esophageal invasion (mm)					0.264
	≥20	14	0	0.0%
	<20	37	4	10.8%
Gastric invasion length (mm)					0.043
	≥40	24	4	16.7%
	<40	27	0	0.0%
Tumor size (mm)					0.405
	≥40	41	4	9.8%
	<40	10	0	0.0%
Invasion of the lesser curvature					0.494
	(+)	43	4	9.3%
	(−)	8	0	0.0%
Histological type					0.290
	Differentiated	25	3	12.0%
	Undifferentiated	26	1	3.8%
Lymphatic invasion involvement					0.186
	Present	34	4	11.8%
	Absent	17	0	0.0%
Venous invasion					0.494
	Present	43	4	9.3%
	Absent	8	0	0.0%
Neural invasion					0.261
	Present	24	3	12.5%
	Absent	27	1	3.7%