Table 5. Adjusted HR estimates for SphK1 expression and recurrence of colon cancer-specific using multivariate Cox regression analysis.

	Multivariate analysis
Variables	Adjusted SHR	95% CI	P value
SphK1 expression
Absence (Ref)	1.0	—	—
Presence	1.35	0.48–3.77	0.564
Age
≤65 years (Ref)	1.0	—	—
>65 years	1.33	0.73–2.42	0.344
Ethnicity
Chinese (Ref)	1.0	—	—
Malays	3.29	1.35–8.02	0.009
Indians	2.17	0.45–10.50	0.336
Others	0.86	0.14–5.23	0.873
Pre-op CEA levels	1.002	1.00–1.001	0.647
AJCC stage
Stages 1 and 2 (Ref)	1.0	—	—
Stages 3 and 4	2.28	1.22–4.29	0.01
Vascular invasion
Absence (Ref)	1.0	—	—
Presence	1.52	0.55–4.23	0.422

CEA, carcinoembryonic antigen; CI, confidence interval; HR, hazard ratio; SHR, sub-hazard ratio; SphK1, sphingosine kinase 1.