Prognostic value of preoperative carcinoembryonic antigen/tumor size in rectal cancer

Table 3 Univariate analysis of prognostic factors for disease-free survival

Variable	Training cohort (n = 371)			Validation cohort (n = 185)
	Hazard ratio	95%CI	P-value	Hazard ratio	95%CI	P-value
Age	1	0.99-1.02	0.572	1.02	0.99-1.04	0.173
Tumor size	1.01	0.91-1.12	0.828	1.12	0.97-1.30	0.128
Sex (ref = male)	1.26	0.85-1.87	0.247	0.75	0.41-1.37	0.353
TNM1 (ref = stage I)	1.9	1.45-2.50	<0.001a	1.6	1.07-2.39	0.023a
Differentiation1 (ref = poor)	0.78	0.58-1.06	0.113	0.6	0.38-0.95	0.031a
Lymphovascular invasion (ref = negative)	2.44	1.45-4.12	0.001a	2.63	1.11-6.22	0.028a
Perineural invasion (ref = negative)	2.17	1.23-3.82	0.008a	1.98	0.78-5.03	0.151
CEA (ref = CEA < 5)	1.55	1.03-2.32	0.034a	1.9	1.05-3.41	0.033a
CA 19-9 (ref = CA 19-9 < 37)	1.43	0.85-2.42	0.177	1.96	0.97-3.96	0.061
CEA/tumor size (ref = low)	1.72	1.10-2.71	0.018a	2.58	1.37-4.85	0.003a

¹These variables were treated as ordinal categorical data;

^aP < 0.05. CEA: Carcinoembryonic antigen; CA 19-9: Carbohydrate antigen 19-9; CI: Confidence interval; ref: Reference.