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

Table 2 Cox proportional hazards regression analysis of overall survival in 23 patients with esophageal squamous cell carcinoma and direct gastric invasion

	Univariable		Multivariable1		Multivariable2
Variable	HR (95%CI)	P value	HR (95%CI)	P value	HR (95%CI)	P value
Age in years
< 58.1	1		1		1
≥ 58.1	1.13 (0.4-2.9)	0.76	1.3 (0.4-4.4)	0.68	0.65 (0.2-2.2)	0.48
Sex
Female	1		1		1
Male	0.68 (0.1-5.4)	0.71	0.1 (0.00-1.8)	0.12	0.2 (0.01-3.7)	0.26
Clinical stage
II	1		1		-
III	1.4 (0.2-11.1)	0.78	2.2 (0.2-24.6)	0.53	-
IV	1.4 (0.2-11.2)	0.77	1.4 (0.2-12.4)	0.78	-
ECOG performance status
0-1	1		1		1
2	18.8 (3.3-107.4)	< 0.01	16.6 (2.7-103.4)	< 0.01	27.2 (3.1-237.2)	< 0.01
T category
T2	1		-		1
T3-T4	1.2 (0.1-8.9)	0.89	-		0.9 (0.1-12.6)	0.94
N category
N0-N1	1		-		1
N2-N3	0.4 (0.1-1.2)	0.11	-		0.5 (0.1-2.2)	0.39
M category
M0	1		-		1
M1	2.1 (0.8-5.8)	0.16	-		2.9 (0.6-13.5)	0.17
Treatment modality
Best supportive care	1		1		1
CRT	0.3 (0.1-1.7)	0.18	0.3 (0.04-1.6)	0.15	0.11 (0.01-1.05)	0.06
CRT followed by surgery	0.1 (0.02-0.7)	0.02	0.03 (0.00-0.5)	0.02	0.03 (0.002-0.6)	0.02

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.