Serological diagnostic factors for liver metastasis in patients with colorectal cancer

Table 1 Methods to determine biomarkers and upper or lower limits of normality used in our laboratory

Diagnostic factors	Methods	Lower and upper limits
Total bilirubin (μmol/L)	Jendrassik-Grof	2-20
Direct bilirubin (μmol/L)	Jendrassik-Grof	0-10
Alanine aminotransferase (U/L)	Rate	0-40
Aspartate aminotransferase (U/L)	Rate	0-42
Serum total protein (g/L)	Biuret	60-80
Globulin (g/L)		27-35
γ-glutamyltransferase (U/L)	Nitrophenol rate	0-50
Alkaline phosphatase (U/L)	P-nitrophenol phosphate rate	45-132
Lactate dehydrogenase (U/L)	Rate	80-240
Carcinoembryonic antigen (μg/L)	Elisa	0-5

Table 2 Characteristics of patients enrolled in our study

	With liver metastasis	Without liver metastasis
Age (yr)	55.69 ± 11.773	55.21 ± 13.225
Sex
Male	32	36
Female	18	20
Primary tumor (UICC stage)
T1	1	0
T2	4	0
T3	12	10
T4	22	23
Lymph node metastasis (UICC stage)
N0	29	12
N1	8	13
N2	2	6

UICC: International Union Against Cancer.

Table 3 Cox regression analysis of patients with colorectal cancer

	χ2	P
Serum total protein (g/L)	0.093	0.761
Globulin (g/L)	< 0.000	0.994
Alanine aminotransferase (U/L)	1.943	0.163
Aspartate aminotransferase (U/L)	0.143	0.705
Total bilirubin (μmol/L)	0.122	0.726
Direct bilirubin (μmol/L)	0.063	0.801
γ-glutamyltransferase (U/L)	1.126	0.289
Alkaline phosphatase (U/L)	1.006	0.316
Lactate dehydrogenase (U/L)	11.254	0.001
Carcinoembryonic antigen (μg/L)	0.159	0.690
Lymph node metastasis	1.601	0.206

Table 4 Levels of γ-glutamyltransferase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and carcinoembryonic antigen in patients with and without liver metastasis of colorectal cancer

	With liver metastasis	Without liver metastasis	P
GGT (U/L)	43.00 (64.75)	24.00 (35)	0.001
ALT (U/L)	22.00 (22.75)	13.00 (12.50)	< 0.001
AST (U/L)	22.00 (17.50)	16.00 (10.00)	< 0.001
LDH (U/L)	201.5 (169.50)	164.50 (70.75)	0.003
CEA (μg/L)	13.70 (93.8)	4.87 (12.82)	0.039

GGT: γ-glutamyltransferase; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; LDH: Lactate dehydrogenase; CEA: Carcinoembryonic antigen.

Table 5 Screening test for liver metastasis in patients with colorectal cancer

	Sen (%)	Spe (%)	DI	CA	AA	PV+	PV-	P	α	β
LDH	64.3	64.0	1.283	0.642	0.641	0.667	0.615	0.003	0.360	0.356
GGT	69.6	60.0	1.296	0.651	0.649	0.661	0.638	0.001	0.400	0.304
CEA	70.4	52.4	1.228	0.625	0.623	0.655	0.579	0.039	0.476	0.296
LDH and CEA (serial test)	51.9	85.7	1.376	0.667	0.695	0.823	0.581	0.007	0.143	0.481
LDH and CEA (parallel test)	85.2	42.9	1.281	0.667	0.657	0.657	0.692	0.030	0.571	0.148
GGT and CEA (serial test)	44.4	85.7	1.301	0.625	0.662	0.800	0.545	0.025	0.143	0.556
GGT and CEA (parallel test)	92.6	38.1	1.307	0.687	0.691	0.658	0.800	0.009	0.619	0.074

LDH: Lactate dehydrogenase; GGT: γ-glutamyltransferase; CEA: Carcinoembryonic antigen; Sen: Sensitivity; Spe: Specificity; DI: Diagnostic index; α: False positive rate; β: False negative rate; CA: Crude accuracy; PV+: Positive predictive value; PV-: Negative predictive value.