Proposal of criteria to select candidates with colorectal liver metastases for hepatic resection: Comparison of our scoring system to the positive number of risk factors

Table 1 Prognostic factors entered into multivariate analysis based on proposed clinical and histopathological features

Variable	n
Gender (male/female)	61/20
Age at hepatectomy(< 60/≥ 60 yr)	32/49
Chronology of hepatic metastasis
(synchronous/metachronous)	41/40
Disease free interval after colectomy
(synchronous or ≤ 1 yr/> 1 yr)	56/25
Extrahepatic distant metastases (no/yes)	9/72
CEA ( ≤ 10 times of normal value/> 10 times of normal value)	57/24
Primary lesion
Depth of invasion (up to subserosa/more)	57/24
Lymph node metastasis (no/yes)	39/42
Hepatic metastasis
Number (single / multiple)	45/36
Maximum diameter ( ≤ 5 cm/> 5 cm)	59/22
Lobe involved (unilobar/bilobar)	64/17
Therapeutic factor
Type of hepatectomy (limited/lobectomy)	56/25
Surgical margin (< 1 cm /≥ 1 cm)	61/20

Table 2 Multivariate analysis for clinicopathological variables with the stepwise analysis of Cox proportional hazard regression model n = 81(Tokyo Univ 1981-1997)

Variable	Parameter	P	Hazard ratio (95% CI)
Diameter > 5 cm	1.35657	0.0013	3.883 (1.703-8.852)
Extrahep met (+)	1.19430	0.0133	3.301 (1.282-8.502)
Number ≥ 2	0.85412	0.0265	2.349 (1.105-4.997)
DF interval < 1 yr	0.67838	0.1602	1.971 (0.765-5.080)
n (+) of primary	0.60034	0.1352	1.823 (0.829-4.007)
≥ se (+) of primary	0.54877	0.1676	1.731 (0.794-3.774)

P > 0.2; Age ≥ 60, Gender, Synchronous, Bilobar invasion, CEA, Major hepatectomy (lobectomy), Surgical margin < 1 cm.

Table 3 The scoring formula (y1) and the positive number of risk factors (y2)

Score (y1) = 1.35657 × (Diameter > 5 cm)

+ 1.19430 ×（Extrahep.met)

+ 0.85412 × (Multiple)

+ 0.67838 × (D.F.I. < 1 yr)

+ 0.60034 × (n+ of Primary)

+ 0.54877 × (≥ se of Primary)

y1: 0 ≤ y1 ≤ 5.2324

Score (y2) = Number of Factors

y2: 0, 1, 2, 3, 4, 5, 6