Dynamic monitoring of serum tumor markers in predicting recurrence after radical gastrectomy for gastric cancer

Table 7 Multivariate Cox regression analysis of factors affecting recurrence after radical gastrectomy

Variable	HR	95%CI	P value
Tumor size ≥ 5 cm (vs < 5 cm)	2.156	1.287-3.613	0.004
Poorly differentiated-undifferentiated (vs well-moderately differentiated)	2.024	1.168-3.508	0.012
TNM stage III (vs stage I-II)	3.245	1.856-5.672	< 0.001
Vascular invasion (yes vs no)	1.847	1.098-3.108	0.021
Neural invasion (yes vs no)	1.726	1.045-2.852	0.033
Progressive elevation of CEA (yes vs no)	3.124	1.687-5.786	< 0.001
Progressive elevation of CA19-9 (yes vs no)	2.856	1.542-5.291	0.001
Progressive elevation of CA72-4 (yes vs no)	2.634	1.418-4.895	0.002
Progressive elevation of CA125 (yes vs no)	2.487	1.325-4.667	0.005
Recurrent elevation of CEA (yes vs no)	2.145	1.158-3.972	0.015
Recurrent elevation of CA19-9 (yes vs no)	1.967	1.054-3.672	0.034

T stage and N stage were removed due to collinearity with tumor-node-metastasis stage (variance inflation factor > 5). Recurrent elevation of carbohydrate antigen 72-4 [hazard ratio (HR) = 1.756, 95%CI: 0.912-3.382, P = 0.092] and carbohydrate antigen 125 (HR = 1.684, 95%CI: 0.875-3.242, P = 0.118) did not reach statistical significance (P > 0.05) in multivariate analysis and were excluded from the final model after stepwise backward selection. Stepwise backward method was used with exclusion criterion P > 0.10. CI: Confidence interval; CEA: Carcinoembryonic antigen; CA19-9: Carbohydrate antigen 19-9; CA72-4: Carbohydrate antigen 72-4; CA125: Carbohydrate antigen 125; TNM: Tumor-node-metastasis; HR: Hazard ratio.