Oncological outcomes and predictors of radiofrequency ablation of colorectal cancer liver metastases

Table 2 Univariate and multivariate analyses for overall survival

Variable	Number of patients (n = 85)	Median OS (mo)	Univariate	Multivariate
			P value	HR (95%CI)	P value
Gender			0.341
Male	56	42
Female	29	35
Age (yr)			0.504
≤ 60	44	35
> 60	41	36
Location of primary tumor			0.229
Colon	62	42
Rectum	23	33
TNM classification			0.208
I, II, or III	52	45
IV	33	33
Tumor differentiation			0.100
Well or moderate	56	36
Poor	29	34
Previous liver resection			0.084
No	65	36
Yes	20	34
EHD			< 0.001	3.676 (1.730-7.811)	0.001
No	63	50
Yes	22	26
Tumor number			< 0.001	2.475 (1.099-5.573)	0.029
1	45	50
2 or 3	40	26
Maximum tumor diameter			< 0.001	3.641 (1.732-7.654)	0.001
≤ 3 cm	48	45
> 3 to 5 cm	37	26
Minimum ablative margin			0.367
≤ 5 mm	44	33
> 5 mm	41	36

OS: Overall survival; EHD: Extrahepatic disease; HR: Hazard ratio; CI: Confidence interval.