Comparative analysis of radiofrequency ablation and resection for resectable colorectal liver metastases

Table 1 Types of surgery for colorectal liver metastasis

Type of surgery		n (%)
Major resection	Right hemihepatectomy	5 (41.7)
Minor resection	Segmentectomy	6 (50.0)
	Left lateral sectionectomy	1 (8.3)
Total		12

Table 2 Summary of patient information

No.	Age (yr)	Sex	Comorbidity	Treatment modality	Location	Timing of metastasis	Recurrence	Results
1	51	M		RFA	Colon	Meta	Yes	S
2	60	M		RFA	Colon	Meta	Yes	D
3	69	M		Resection	Colon	Meta	Yes	D
4	76	M	DM, HT	Resection	Rectum	Meta	Yes	D
5	62	M		RFA	Colon	Syn	No	S
6	61	M	DM	RFA	Rectum	Meta	Yes	D
7	70	F		Resection	Colon	Meta	Yes	S
8	70	M		Resection	Rectum	Meta	No	S
9	71	F		Resection	Rectum	Meta	Yes	S
10	69	F	DM, HT	Resection	Colon	Syn	Yes	S
11	74	F		Resection	Colon	Syn	No	S
12	71	M		Resection	Colon	Meta	Yes	S
13	82	M		Resection	Rectum	Meta	Yes	D
14	58	F		RFA	Colon	Meta	No	S
15	60	M		RFA	Colon	Syn	Yes	D
16	56	F		RFA	Colon	Meta	Yes	S
17	56	M		RFA	Colon	Meta	Yes	S
18	54	F		RFA	Colon	Meta	Yes	D
19	52	F		RFA	Rectum	Meta	No	S
20	60	M		RFA	Colon	Meta	Yes	D
21	55	M		RFA	Rectum	Meta	Yes	D
22	75	M		Resection	Colon	Syn	Yes	D
23	54	F		RFA	Rectum	Meta	Yes	D
24	63	F		RFA	Colon	Syn	Yes	D
25	66	M		Resection	Rectum	Syn	Yes	S
26	56	F		RFA	Rectum	Meta	Yes	D
27	67	M		Resection	Colon	Meta	Yes	D
28	58	M		RFA	Rectum	Syn	No	S
29	71	M		Resection	Colon	Meta	Yes	S

DM: Diabetes mellitus; HT: Hypertension; RFA: Radiofrequency ablation; Meta: Metachronous; Syn: Synchronous; S: Survival; D: Death; M: Male; F: Female.

Table 3 Summary of pathological findings

No.	Metastatic tumor size (cm)	Diff	T	N	M	LNR	LV	PN
1	2.5	Mod	3	2	0	0.23	Pos	Pos
2	1.6	Mod	3	2	0	0.17	Pos	Pos
3	4	Mod	4	2	0	0.37	Pos	Pos
4	4.2	Mod	4	1	0	0.43	Pos	Pos
5	3.2	Mod	3	1	1	0.07	Pos	Neg
6	4.2	Mod	2	2	0	0.25	Pos	Pos
7	4	Mod	3	0	1	0	Pos	Pos
8	2.8	Mod	4	0	0	0	Pos	Pos
9	4.4	Mod	1	2	0	0.06	Neg	Neg
10	4.9	Well	3	1	1	0.03	Pos	Neg
11	2.8	Mod	3	0	0	0	Neg	Pos
12	2.3	Mod	4	1	0	0.08	Neg	Neg
13	3.2	Mod	4	2	1	0.33	Neg	Pos
14	1.2	Mod	3	2	0	0.14	Pos	Pos
15	0.9	Poor	3	2	0	0.12	Pos	Pos
16	1.7	Poor	3	1	0	0.04	Pos	Pos
17	2	Mod	3	1	0	0.03	Neg	Neg
18	1	Mod	3	2	0	0.34	Pos	Pos
19	2.5	Mod	4	0	0	0	Neg	Neg
20	2	Mod	3	1	0	0.14	Pos	Pos
21	1.6	Mod	3	1	0	0.08	Pos	Pos
22	1	Mod	3	1	0	0.04	Pos	Pos
23	3.8	Mod	2	0	0	0	Neg	Neg
24	3.7	Mod	3	0	1	0	Neg	Neg
25	1	Mod	3	0	0	0	Neg	Neg
26	3.6	Mod	4	2	1	0.58	Neg	Pos
27	1.2	Mod	3	0	0	0	Pos	Pos
28	0.8	Mod	4	1	1	0.03	Neg	Neg
29	1.3	Mod	3	0	0	0	Neg	Neg

Diff: Differentiation of primary tumor; T: T stage; N: N stage; M: M stage; LNR: Lymph node ratio; LN: Lymphovascular invasion; PN: Perineural invasion; Mod: Moderate; Poor: Poorly; Pos: Positive; Neg: Negative.

Table 4 Clinicopathological data of colorectal liver metastasis n (%)

		RFA (n = 17)	Resection (n = 12)	P-value
Sex	Male	7 (41)	4 (33)	0.49
	Female	10 (59)	8 (67)
Age (yr)		61.35 ± 8.33	67.50 ± 7.44	0.07
Age (yr)	≤ 65	12 (71)	4 (33)	0.07
	> 65	5 (29)	8 (67)
Timing of metastasis	Synchronous	5 (29)	3 (25)	1.00
	Metachronous	12 (71)	9 (75)
Primary site	Colon	10 (59)	8 (67)	0.72
	Rectum	7 (41)	4 (33)
T stage	I-III	13 (76)	8 (67)	0.68
	IV	4 (24)	4 (33)
Lymphovascular	Positive	8 (47)	8 (67)	0.45
Invasion	Negative	9 (53)	4 (33)
Perineural invasion	Positive	10 (59)	7 (58)	1.00
	Negative	7 (41)	5 (42)
Lymph node metastasis	Positive	11 (65)	9 (75)	0.69
	Negative	6 (35)	3 (25)
Size of metastasis (cm)		2.02 ± 1.17	3.59 ± 0.81	0.03
Size of metastasis	≤ 3 cm	13 (76)	5 (42)	0.07
	> 3 cm	4 (24)	7 (58)
Recurrence	Yes	14 (82)	9 (75)	0.67
	No	3 (18)	3 (25)

RFA: Radiofrequency ablation.

Table 5 Univariate analysis of 5-year overall survival

		RFA (n = 17)		Resection (n = 12)		P-value
		3-yr	5-yr	3-yr	5-yr
Sex	Female	42.9%	42.9%	100%	100%	0.083%
	Male	60.0%	30.0%	50.0%	50.0%	0.925%
Age (yr)	≤ 65	58.3%	38.9%	50.0%	50.0%	0.848%
	> 65	40.0%	40.0%	75.0%	75.0%	0.187%
Primary	1-3	50.0%	33.3%	75.0%	75.0%	0.194%
T stage	4	66.7%	66.7%	50.0%	50.0%	0.847%
Timing of	Synchronous	33.3%	33.3%	100%	100%	0.093%
Metastasis	Metachronous	63.6%	42.4%	55.6%	55.6%	0.975%
Preoperative chemotherapy	No	50.0%	50.0	66.7	66.7	0.410
	Yes	54.5%	36.4%	66.7%	66.7%	0.495%
Primary site	Colon	50.0%	37.5%	75.0%	75.0%	0.202%
	Rectum	57.1%	38.1%	50.0%	50.0%	0.992%
Metastatic	Negative Positive	50.0%	50.0%	100%	100%	0.175%
Lymph node		54.5%	32.7%	55.6%	55.6%	0.502%
Lymphovascular invasion	Negative	55.6%	55.6%	100%	100%	0.140%
	Positive	50.0%	25.0%	50.0%	50.0%	0.638%
Perineural invasion	Negative Positive	71.4%	71.4%	100%	100%	0.214%
		40.0%	20.0%	42.9%	42.9%	0.515%
Primary	≤ 3 cm	69.2%	49.50%	80.0%	80.0%	0.464%
Tumor size	> 3 cm	0.0%	0.0%	57.1%	57.1%	0.005%
Postoperative chemotherapy	No	20.0%	20.0%	0.0%	0.0%	0.929%
	Yes	66.7%	47.6%	80.0%	80.0%	0.341%

RFA: Radiofrequency ablation.

Table 6 Univariate analysis of 5-year disease-free survival

		RFA (n = 17)		Resection (n = 12)		P-value
		3-yr	5-yr	3-yr	5-yr
Sex	Female	28.6%	28.6%	50.0%	50.0%	0.350
	Male	10.0%	10.0%	50.0%	33.3%	0.039
Age (yr)	≤ 65	25.0%	25.0%	50.0%	25.0%	0.449
	> 65	0.0%	0.0%	46.9%	46.9%	0.012
Primary	I-III	7.1%	7.1%	50.0%	25.0%	0.023
T Stage	IV	66.7%	66.7%	50.0%	50.0%	0.702
Timing of	Synchronous	16.7%	16.7%	66.7%	66.7%	0.201
Metastasis	Metachronous	18.2%	18.2%	41.7%	20.8%	0.172
Preoperative chemotherapy	No	16.7%	16.7%	53.3%	53.3%	0.112
	Yes	18.2%	18.2%	33.3%	0.0%	0.617
Primary site	Colon	10.0%	10.0%	50.0%	25.0%	0.048
	Rectum	28.6%	28.6%	37.5%	37.5%	0.385
Metastatic	Negative	16.7%	16.7%	100.0%	100.0%	0.037
Lymph node	Positive	18.2%	18.2%	29.6%	14.8%	0.325
Lymphovascular invasion	Negative	22.2%	22.2%	50.0%	50.0%	0.137
	Positive	12.5%	12.5%	50.0%	33.3%	0.197
Perineural invasion	Negative	28.6%	28.6%	40.0%	40.0%	0.423
	Positive	10.0%	10.0%	57.1%	28.6%	0.074
Primary	≤ 3 cm	23.1%	23.1%	60.0%	30.0%	0.204
Tumor size	> 3 cm	0.0%	0.0%	38.1%	38.1%	0.013
Postoperative chemotherapy	No	0.0%	0.0%	50.0%	50.0%	0.151
	Yes	25.0%	25.0%	50.0%	33.3%	0.235

RFA: Radiofrequency ablation.