Table 3.

Multivariate analysis of factors predictive of low risk (negative lymph node metastasis and recurrence-free survival) following endoscopic submucosal resection for esophageal squamous cell carcinoma

Variable	OR	95% CI	p value
Differentiation	0.138	0.085–0.524	< 0.001*
Depth of invasion (sm1)	0.246	0.115–0.634	< 0.001*
Tumor length (< 20 mm)	1.085	1.142–1.231	< 0.001*

CI confidence interval, OR odds ratio, sm1 invasion of the upper third of the submucosal layer or reaching the submucosal layer > 200 µm from the muscularis