Table 2. Univariate analysis of predictors of lymph node metastasis.

Variable	No metastasis	Metastasis	P
	(n = 239)	(n = 203)
Gender			0.335
Male	168	134
Female	71	69
Age (years)			0.526
≤50	64	49
>50	175	154
Tumor size (cm)			0.007
<6	220	170
≥6	19	33
Tumor location			0.662
Upper third	56	45
Middle third	39	26
Lower third	133	120
Two or more thirds	11	12
Histological type			0.147
Well differentiated	10	3
Moderate differentiated	72	57
Poor differentiated	144	137
Undifferentiated	13	6
Depth of invasion in muscularis propria			0.022
Shallow layer	154	109
Deep layer	85	94
Vascular tumor emboli			0.000
Yes	29	76
No	210	127
Nervous invasion			0.097
Yes	30	37
No	209	166