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

Table 1 Univariate and multivariate analyses for local tumor progression-free survival

Variable	Number of tumors (n = 138)	LTP rate (%)	Univariate	Multivariate
			P value	HR (95%CI)	P value
Gender			0.052
Male	91	27.5
Female	47	42.6
Age (yr)			0.653
≤ 60	76	30.3
> 60	62	35.5
Location of primary tumor			0.868
Colon	99	32.3
Rectum	39	33.3
TNM classification			0.502
I, II, or III	81	30.9
IV	57	35.1
Tumor differentiation			0.591
Well or moderate	81	34.6
Poor	57	29.8
Previous liver resection			0.120
No	105	29.5
Yes	33	42.4
EHD			0.522
No	93	32.3
Yes	45	33.3
Tumor number			0.799
1	45	35.6
2 or 3	93	31.2
Tumor size			< 0.001	3.712 (1.894-7.277)	< 0.001
≤ 3 cm	86	15.1
> 3 to 5 cm	52	61.5
Ablative margin			< 0.001	3.077 (1.479-6.405)	0.003
≤ 5 mm	67	52.2
> 5 mm	71	14.1

LTP: Local tumor progression; LTPFS: Local tumor progression-free survival; EHD: Extrahepatic disease; HR: Hazard ratio; CI: Confidence interval.