Table 2. Univariate analysis of prognostic factors of esophagitis grade ≥2.

Variable	P value	HR (95% CI)
Age (<65 vs. ≥65)	0.591	1.244 (0.560–2.765)
Sex (male/female)	0.317	0.55 (0.170–1.776)
Tumor location (cervical/upper/middle/lower)	0.457	0.828 (0.504–1.361)
Clinical stage (I–II vs. III–IV)	0.356	1.649 (0.570–4.770)
Treatment (radiotherapy/chemoradiotherapy/preoperative chemoradiotherapy)	0.185	1.481 (0.829–2.646)
Dose (≤40 vs. >40)	0.015*	2.864 (1.230–6.671)
GTV (<50 vs. ≥50)	0.136	1.904 (0.817–4.440)
PTV (<495 vs. ≥495)	0.049*	2.336 (1.004–5.435)
BMI (underweight/normal/overweight)	0.898	1.000 (0.505–1.981)
PG-SGA (<9 vs. ≥9)	0.001*	3.948 (1.699–9.174)
WL (<10% vs. ≥10%)	0.019*	2.690 (1.180–6.131)
ALB (≥35 vs. <35)	0.043*	2.507 (1.027–6.116)
HB (>120 vs. ≤120)	0.756	0.840 (0.279–2.526)
CRP (<10 vs. ≥10)	0.469	0.594 (0.617–3.052)
ADS (≤1vs. >1)	0.438	1.372 (0.716–3.416)
GPS (0 vs.1/2)	0.186	1.742 (0.765–3.968)

*, statistical significance at P<0.05. GTV, gross tumor volume; PTV, planning tumor volume; BMI, body mass index; PG-SGA, Patient-Generated Subjective Global Assessment; ALB, albumin; HB, hemoglobin; CRP, C-reactive protein; ADS, Atkinson dysphagia score; GPS, Glasgow prognostic score.