TABLE 4.

Multivariable analysis for MPT development using the Cox proportional hazards regression model

Variables	Multivariate analysis
	HR (95% CI)	p‐Value
Sex
Male	1.593 (1.286–1.974)	<0.001
Female	Reference
Age
<70	1.507 (1.194–1.900)	0.001
≥70	Reference
Metastasis
Yes	1.057 (0.791–1.411)	0.709
No	Reference
ESCC tumour stage
Low (0/I/II)	1.497 (1.188–1.887)	0.001
High (III/IV)	Reference

Abbreviations: CI, confidence interval; HR, hazard ratio; MPT, multiple primary tumour.