Table 2.

Association between prognostic factors and overall survival in 388 patients with detectable serum levels of CA 19-9^a

Variables	HR	95% CI	P value
RAS/BRAF mutation status
RAS/BRAF wild-type			0.003b
CA 19-9 <35 kU/L	1
CA 19-9 ≥35 kU/L	1.35	0.96–1.91
RAS mutation
CA 19-9 <35 kU/L	1
CA 19-9 ≥35  kU/L	1.43	1.00–2.05
BRAF mutation
CA 19-9 <35 kU/L	1
CA 19-9 ≥35 kU/L	4.35	2.89–8.28
CEA level
<5 µg/L	1		0.036
≥5 µg/L	1.41	1.02–1.94
WHO performance status
0	1		0.004
1	1.37	1.07–1.76
2	2.56	1.31–3.89
Alkaline phosphatase level
Normal	1		0.003
>UNL	1.44	1.13–1.82
CRP level
Per categoryc	1.17	1.05–1.31	0.006

CI confidence interval, CEA carcinoembryonic antigen, CA carbohydrate antigen, CRP C-reactive protein, HR hazard ratio, OS overall survival, UNL upper normal limit, WHO World Health Organization

^a Adjusted model including the interaction between tumour RAS/BRAF mutation status and CA 19-9.

^b Interaction P.

^c CRP categories: from 0 to 10 mg/L, from 10 to 30 mg/L, from 30 to 60 mg/L, from 60 mg/L and higher.