Diagnostic performance of diffusion-weighted magnetic resonance imaging in assessing lymph node metastasis of esophageal cancer compared with PET

Table 7 Risk factors for relapse-free survival by univariate and multivariate analysis

Clinical risk factor	Category	Univariate analysis			Multivariate analysis
Clinical risk factor	Category	Hazard ratio	95% CI	P value	Hazard ratio	95% CI	P value
Age	< 67	1.605	0.798–3.229	0.185
Age	≥ 67
Gender	Female	1.427	0.619–3.290	0.404
Gender	Male
Tumor location	Upper/middle	1.008	0.506–2.012	0.981
Tumor location	Lower/abdominal
Histological grade	G3	1.056	0.408–2.738	0.910
Histological grade	G1/G2
Lymphadenectomy	2-field	1.135	0.492–2.616	0.766
Lymphadenectomy	3-field
Clinical T stage	T3/T4a	5.101	2.515–10.348	< 0.001
Clinical T stage	T1/T2
Clinical N stage	N2/N3	4.575	2.022–10.353	< 0.001
Clinical N stage	N0/N1
Clinical M stage	M1	5.768	1.304–25.506	0.021
Clinical M stage	M0
Clinical stage	III/IV	3.845	1.920–7.702	< 0.001	1.596	0.709–3.591	0.259
Clinical stage	I/II
DWI-N status	DWI-N+	4.786	2.149–10.660	< 0.001	2.642	1.010–6.913	0.048
DWI-N status	DWI-N0
PET-N status	PET-N+	4.778	2.384–9.577	< 0.001	2.418	1.076–5.436	0.033
PET-N status	PET-N0

95% CI 95% confidence interval,DWI diffusion-weighted magnetic resonance image, PET positron emission tomography, Upper, middle and lower location of thoracic esophagus, N + positive for metastasis