Differential effects of the KRAS gene on recurrence in right- vs left-sided colorectal liver metastases undergoing radiofrequency ablation

Table 4 Univariable and multivariable analyses of prognostic factors for overall survival for colorectal liver metastases

Prognostic factor	Univariable analysis		Multivariable analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Age (year)	1.057 (0.707-1.579)	0.787
Tumor size > 3 cm	1.598 (1.037-2.464)	0.034	1.829 (1.124-2.972)	0.015
Sex	0.898 (0.599-1.347)	0.604
Right colon	2.098 (1.258-3.498)	0.005	2.234 (1.298-3.845)	0.004
Pathological differentiation/poorly	1.465 (0.813-2.638)	0.203
KRAS mutation	1.681 (1.123-2.515)	0.012	1.325 (0.865-2.031)	0.196
T stage	1.338 (0.583-3.070)	0.492
Lymph node metastases	1.317 (0.787-2.201)	0.294
Synchronous liver metastasis	1.267 (0.846-1.898)	0.252
No. of liver metastases	1.708 (1.124-2.594)	0.012	1.469 (0.839-2.570)	0.178
Liver metastasis resection pre-RFA	0.803 (0.526-1.226)	0.310
Extrahepatic metastases	1.849 (1.229-2.782)	0.003	1.700 (1.113-2.598)	0.014
CRS	1.690 (1.115-2.561)	0.013	1.174 (0.658-2.095)	0.587
CEA	1.069 (0.636-1.797)	0.802
DFI	1.279 (0.755-2.167)	0.360
Margin	1.216 (0.843-1.755)	0.295
Preoperative chemotherapy	1.623 (0.751-3.508)	0.218

DFI: Disease-free interval from primary resection to the diagnosis of liver metastasis; CRS: Clinical risk score, including node-positive primary tumor, DFI < 12 months, more than one liver tumor, size of largest tumor > 3 cm, carcinoembryonic antigen level > 30 ng/mL (mg/L); RFA: Radiofrequency ablation; CEA: Carcinoembryonic antigen.