Direct gastric invasion is associated with poor prognosis in esophageal squamous cell carcinoma involving the lower-third esophagus

Table 4 Cox proportional hazards regression analysis of overall survival in 176 patients with esophageal squamous cell carcinoma involving the lower third of the esophagus, n (%)

	Univariable		Multivariable1		Multivariable2
Variable	HR (95%CI)	P value	HR (95%CI)	P value	HR (95%CI)	P value
Gastric invasion
No	1		1		1
Yes	2.5 (1.4-4.4)	0.001	2.2 (1.2-3.9)	0.01	1.9 (1.0-3.7)	0.04
Age in years
< 57.3	1		1		1
≥ 57.3	1.1 (0.8-1.6)	0.53	0.8 (0.5-1.2)	0.25	0.8 (0.5-1.2)	0.21
Sex
Female	1		1		1
Male	1.1 (0.4-2.9)	0.92	0.6 (0.2-1.6)	0.32	0.7 (0.2-1.8)	0.41
Clinical stage
I-II	1		1		-
III	1.1 (0.5-2.2)	0.82	1.2 (0.6-2.5)	0.58	-
IV	2.2 (1.1-4.7)	0.03	1.7 (0.8-3.7)	0.15	-
Treatment
CRT	1		1		1
CRT followed by surgery	0.3 (0.2-0.5)	< 0.001	0.3 (0.2-0.5)	0.01	0.3 (0.2-0.5)	< 0.001
ECOG performance status
0	1		1		1
1	1.0 (0.6-1.9)	0.89	1.0 (0.5-2.0)	0.95	0.9 (0.4-1.8)	0.71
2	2.3 (0.9-6.2)	0.09	1.8 (0.6-5.1)	0.27	1.6 (0.5-4.6)	0.43
T category
T2	1		-		1
T3	0.8 (0.5-1.5)	0.60	-		1.2 (0.6-2.6)	0.62
T4	1.7 (0.9-3.2)	0.08	-		1.5 (0.7-3.0)	0.27
N category
N0	1		-		1
N1	1.4 (0.7-2.8)	0.35	-		1.3 (0.6-2.8)	0.55
N2	1.1 (0.5-2.3)	0.77	-		1.0 (0.4-2.1)	0.95
N3	1.4 (0.6-3.1)	0.41	-		1.0 (0.4-2.3)	> 0.99
M category
M0	1		-		1
M1	3.0 (1.8-4.9)	< 0.001	-		1.7 (0.9-2.9)	0.06

¹Multivariable model adjusted for age, sex, clinical stage, Eastern Cooperative Oncology Group performance status, and treatment modality.

²Multivariable model adjusted for age, sex, clinical T category, clinical N category, clinical M category, Eastern Cooperative Oncology Group performance status, and treatment modality.

ECOG: Eastern Cooperative Oncology Group; CI: Confidence interval; CRT: Chemoradiotherapy; HR: Hazard ratio.