Table 4. COX regression analysis of prognostic factors for stage pN0 ESCC patients with negative LN metastasis on preoperative CT scan.

Variables	Univariate COX regression			Multivariate COX regression
	HR (95% CI)	P value		HR (95% CI)	P value
Gender
Male	Reference			Reference
Female	0.147 (0.020–1.082)	0.060		0.163 (0.022–1.207)	0.076
Age, years
<60	Reference
≥60	1.196 (0.528–2.708)	0.668
Position		0.624
Upper	Reference
Middle	0.808 (0.240–2.726)	0.731
Lower	0.803 (0.191–3.383)	0.765
Surgery
Left	Reference
Right	1.085 (0.515–2.287)	0.830
Three-incisions	0.289 (0.037–2.241)	0.235
T stage
T1+T2	Reference			Reference
T3+T4	2.058 (0.981–4.315)	0.056		2.212 (1.051–4.654)	0.036
Length
<3	Reference
<5	0.780 (0.306–1.989)	0.603
≥5	1.613 (0.651–3.994)	0.302
Differentiation
High	Reference
Moderately	1.965 (0.447–8.642)	0.586
Poorly	2.908 (0.645–13.115)	0.165
Harvested LNs
<12	Reference			Reference
≥12	0.429 (0.206–0.893)	0.024		0.409 (0.196–0.856)	0.018
Adjuvant therapy
No	Reference
Yes	1.406 (0.670–2.949)	0.368