Table 4.

Multivariate analyses (Cox regression model) of overall survival of all patients and of patients having a normal pretreatment serum carcinoembryonic antigen

Variable	Hazard ratio	95% CI	P value
All patients
Perioperative chemotherapy	0.723	0.501–1.044	0.084
T staging	1.422	1.067–1.896	0.016
Lymph node metastasis rate	1.302	1.101–1.539	0.002
Normal-CEA patients
Perioperative chemotherapy	0.670	0.434–1.033	0.070
T staging	1.443	1.041–2.000	0.028
Lymph node metastasis rate	1.274	1.053–1.542	0.013

CEA: Carcinoembryonic antigen.