Impact of timing and cycles of systemic chemotherapy on survival outcome of colorectal liver metastases patients treated by percutaneous microwave ablation

Figures & data

Table 1. Baseline data for the study cohort.

Characteristics	Value (% or range)
Total	199 (100)
Age in years, median (range)	60 (30–86)
≤60 years	107 (53.8)
>60 years	92 (46.2)
Gender
Male	132 (66.3)
Female	67 (33.7)
Primary tumour
Colon	114 (57.3)
Rectum	85 (42.7)
Node status
Positive	142 (71.4)
Negative	57 (28.6)
Histology grade
High differentiation	26 (13.1)
Moderate differentiation	133 (66.8)
Poor differentiation	40 (20.1)
CLM
Synchronous	116 (58.3)
Metachronous	83 (41.7)
Number of CLM median (range)	1 (1–3)
1 CLM	119 (59.8)
2–3 CLM	80 (40.2)
Maximum size in cm, median (range)	3 (1–5)
≤4 cm	148 (74.4)
>4 cm	51 (25.6)
Topography
Unilobar	160 (80.4)
Bilobar	39 (19.6)
Major complications
Yes	7 (3.5)
No	192 (96.5)
Chemotherapy status
Use of pre-ablative chemotherapy†	148 (74.4)
Use of post-ablative chemotherapy#	142 (73.6)
Follow-up in months, median (range)	30.2 (6.0–68.4)
Loss	6 (3.0)
Total number with follow-up	193 (97.0)

†Data based on the total 199 patients.

#Data based on the 193 patients with full information of follow-up.

CLM, colorectal liver metastases.

Table 2. Univariate analysis of prognostic factors for progression free survival and overall survival.

Factors	No. (%)	PFS		OS
		Median months (95% CI)	Log-rank p-value	Median months (95% CI)	Log-rank p-value
Age			0.638		<0.001*
≤60 years	104 (53.9)	22.8 (17.3–28.3)		56.3 (39.3–73.4)
>60 years	89 (46.1)	17.4 (12.3–22.6)		35.1 (30.8–39.3)
Gender			0.858		0.469
Male	128 (66.3)	21.0 (15.5–26.6)		40.2 (37.0–43.4)
Female	65 (33.7)	17.1 (8.7–25.5)		51.2 (39.3–63.2)
Primary tumour			0.215		0.451
Colon	112 (58.0)	21.1 (12.7–29.5)		39.7 (35.7–43.7)
Rectum	81 (42.0)	18.6 (14.0–23.2)		48.0 (36.9–59.1)
Node status			0.303		0.557
Positive	138 (71.5)	15.4 (11.7–19.1)		39.7 (35.3–44.2)
Negative	55 (28.5)	22.9 (17.5–28.4)		44.9 (36.0–53.9)
Histology grade			0.327		0.960
High differentiation	26 (13.5)	28.8 (22.4–35.2)		48.2 (34.6–61.7)
Moderate differentiation	128 (66.3)	19.7 (15.5–23.9)		40.2 (37.4–43.0)
Poor differentiation	39 (20.2)	14.6 (9.9–19.3)		Not reached
Character			0.472		0.869
Synchronous	112 (58.0)	16.6 (12.1–21.7)		40.4 (32.8–48.0)
Metachronous	81 (42.0)	22.8 (17.8–27.8)		43.1 (33.4–52.7)
Number of CLM			<0.001*		0.026*
1 CLM	115 (59.6)	25.3 (21.8–28.8)		51.2 (43.6–58.8)
2–3 CLM	78 (40.4)	14.5 (12.8–16.1)		28.4 (34.6–42.2)
Maximum size			<0.001*		<0.001*
≤4 cm	145 (75.1)	25.1 (21.3–29.0)		48.0 (37.4–58.6)
>4 cm	48 (24.9)	12.3 (8.4–16.2)		35.5 (27.9–43.1)
Topography			<0.001*		0.068
Unilobar	155 (80.3)	24.1 (18.8–29.4)		48.0 (37.9–58.1)
Bilobar	38 (19.7)	12.4 (10.0–14.7)		36.6 (30.7–42.4)
Pre-ablative chemotherapy			0.446		0.292
No	48 (24.9)	19.7 (6.1–33.3)		Not reached
Yes	145 (75.1)	21.0 (16.8–25.3)		40.4 (35.1–45.7)
Post-ablative chemotherapy			0.111		0.002*
No	51 (26.4)	14.7 (8.5–20.9)		35.1 (28.4–41.7)
Yes	142 (73.6)	22.8 (19.4–28.2)		48.0 (38.1–57.9)

*p-value <0.05 considered statistically significant.

CLM, colorectal liver metastases; OS, overall survival; PFS, progression free survival.

Table 3. Multivariate analysis of prognostic factors for progression free survival and overall survival.

Factors	PFS		OS
	HR (95% CI)	p-value	HR (95% CI)	p-value
Age	1.081 (0.745–1.570)	0.682	2.310 (1.362–3.918)	0.002*
Gender	0.913 (0.622–1.341)	0.644	0.806 (0.466–1.394)	0.439
Primary tumour	1.167 (0.816–1.671)	0.398	0.743 (0.458–1.205)	0.229
Node status	0.702 (0.472–1.043)	0.080	0.862 (0.484–1.534)	0.614
Histology grade		0.561		0.962
Moderate	1.278 (0.740–2.209)	0.379	1.093 (0.558–2.139)	0.796
Poor	1.408 (0.749–2.645)	0.287	1.114 (0.469–2.644)	0.807
Character	1.021 (0.708–1.474)	0.910	0.717 (0.417–1.234)	0.229
Number of CLM	1.925 (1.259–2.943)	0.003*	1.830 (0.997–3.360)	0.051
Maximum size	2.240 (1.497–3.352)	<0.001*	2.035 (1.226–3.379)	0.006*
Topography	1.678 (1.053–2.674)	0.030*	1.208 (0.615–2.374)	0.583
Pre-ablative chemotherapy	1.508 (0.968–2.349)	0.069	1.932 (0.981–3.806)	0.057
Post-ablative chemotherapy	0.781 (0.521–1.169)	0.229	0.573(0.332–0.990)	0.046*

*p-value <0.05 considered statistically significant.

CLM, colorectal liver metastases; HR, hazard ratio; OS, overall survival; PFS, progression-free survival.

Table 4. Multivariate analysis of the impact of different systemic chemotherapy cycles on progression free survival and overall survival.

Cycles	No.	PFS			OS
		Median months (range)	HR (95% CI)	p-value	Median months (range)	HR (95% CI)	p-value
Pre-chemotherapy				0.193			0.224
0	48	19.7 (6.1–33.3)	Reference		Not reached	Reference
1–6	68	22.0 (14.4–29.6)	1.324 (0.797–2.199)	0.279	40.1 (34.6–45.7)	1.817 (0.867–3.807)	0.114
>6	77	18.6 (14.5–22.6)	1.556 (0.964–2.512)	0.070	41.0 (31.5–50.4)	1.831 (0.869–3.857)	0.112
Post-chemotherapy				0.267			0.052
0	51	14.7 (8.5–20.9)	Reference		35.1 (28.4–41.7)	Reference
1–6	71	17.3 (11.4–23.6)	0.888 (0.557–1.415)	0.617	40.2 (33.5–40.9)	0.697 (0.381–1.274)	0.240
>6	71	25.1 (23.0–27.2)	0.697 (0.444–1.095)	0.118	56.3 (30.0–82.7)	0.416 (0.206–0.844)	0.015*

*p-value <0.05 considered statistically significant.

HR, hazard ratio; OS, overall survival; PFS, progression-free survival.

Reference: the control for another two subgroups.