Table 4.

Univariate and multivariate analysis of overall survival

Variable	N	5-Year OS (%)	UV P	MVa P	HR (95% CI)
All patients	119	26
Patient factors
Gender
Male	79	23	0.12	–	–
Female	40	30
Age at hepatectomy
<60 years	46	21	0.49	–	–
≥60 years	73	29
Primary malignancy
Location
Colon	95	25	0.73	–	–
Rectum	24	29
T classification
1–2	9	22	0.24	–	–
3–4	74	24
N classification
0	33	25	0.77	–	–
1–2	52	18
CLM at diagnosis
Timing of diagnosisb
Synchronous	41	14	0.009	NS	–
Metachronous	78	33
No. of CLM
<4	78	32	0.002	<0.001	2.6 (1.6–4.3)
≥4	37	17
Max. size of CLM
<35 mm	50	34	0.005	0.002	2.2 (1.3–3.7)
≥35 mm	58	16
Distribution
Unilateral	61	35	0.004	NS	–
Bilateral	57	16
Initial resectability
Yes	64	40	0.01	NS	–
No	55	15
Hepatic resection
Preoperative chemotherapy
Total no. of lines
1	87	30	0.6	–	–
≥2	32	13
Total no. of cycles
<10	72	34	0.13	–	–
≥10	40	7
Regimen last preoperative line
5-FU LV	32	25	0.17	–	–
5-FU LV oxaliplatin	61	32
5-FU LV irinotecan	18	16
Other	8	0
Chronomodulated therapy
Yes	59	28	0.57	–	–
No	60	23
Radiological response at CT scanc
Response or stabilization	100	29	0.09	0.004	2.6 (1.3–4.9)
Progression	19	7
Biological response, CEAd
Response or stabilization	89	28	0.36	–	–
Progression	24	14
Biological response, CA19.9d
Response or stabilization	56	33	0.002	NS	–
Progression	12	0
Extent of hepatic resection
Minor (<3 segments)	57	32	0.06	NS	–
Major (≥3 segments)	62	20
Resection type
Anatomical	58	31	0.49	–	–
Nonanatomical	26	29
Both	35	12
Vascular occlusion
Yes	97	25	0.95	–	–
No	17	30
Intraoperative RBC transfusion
Yes	32	25	0.85	–	–
No	60	30
Postoperative chemotherapy
Yes	105	27	0.37	–	–
No	11	12
Surgical margin statuse
R0	71	28	0.16	–	–
R1	43	21
R2	4	25

OS overall survival, UV univariate, MV multivariate, HR hazard ratio, CI confidence interval, CLM colorectal liver metastases, NS not significant, 5-FU 5-fluorouracil, LV leucovorin, CT computed tomography, CEA carcinoembryonic antigen, CA carbohydrate antigen, RBC red blood cell

^aVariables with univariate P ≤ 0.10 were entered in the Cox regression model

^bSynchronous = diagnosed before, during, or within 3 months after colorectal resection

^cAccording to RECIST criteria22

^dCutoff point 20%

^eR0: complete surgical resection with a negative surgical margin at histopathology; R1: invaded surgical margins according to the pathologist; R2: macroscopic tumor remnant intraoperatively