Correlation between pre-treatment serum total blood bilirubin and unconjugated bilirubin and prognosis in patients with colorectal cancer

Table 1 Determination of optimal cut-off values for total bilirubin and unconjugated bilirubin (%)

	Cut-off (μmol/L)	Sensitivity	Specificity	Jordan index	Area	95%CI
TBIL	13.45	67.9	72.1	0.400	0.660	0.565-0.755
UCB	10.75	67.9	82.0	0.499	0.735	0.646-0.823

TBIL: Total bilirubin; UCB: Unconjugated bilirubin; CI: Confidence interval.

Table 2 Relationship between total bilirubin level grouping and basic clinical characteristics of patients (mean ± SD)

		TBIL ≤ 13.45 μmol/L (n = 70)	TBIL > 13.45 μmol/L (n = 72)	t/χ2	P value
Age (yr)		65.21 ± 8.33	63.03 ± 9.73	1.437	0.153
TBIL (μmol/L)		10.65 ± 2.11	17.70 ± 4.43	12.163	< 0.001
UCB (μmol/L)		8.81 ± 2.42	13.48 ± 4.10	8.297	< 0.001
Sex	Male	49 (70.0)	42 (58.3)	2.099	0.147
	Female	21 (30.0)	30 (41.7)
Grade	High	20 (18.6)	26 (36.1)	16.039	< 0.001
	Middle	16 (22.9)	33 (45.8)
	Low	34 (48.6)	13 (18.1)
Diameter	< 5 cm	26 (37.1)	38 (52.8)	3.505	0.061
	≥ 5 cm	44 (62.9)	34 (47.2)
Site	Rectum	26 (37.1)	34 (47.2)	1.508	0.471
	Right	20 (28.6)	18 (25.0)
	Left	24 (34.3)	20 (27.8)
Lymph node metastasis	No	27 (38.6)	40 (55.6)	4.108	0.043
	Yes	43 (61.4)	32 (44.4)
TNM	Ⅰ	23 (32.9)	34 (47.2)	6.077	0.048
	Ⅱ	22 (31.4)	25 (34.7)
	Ⅲ	25 (35.7)	13 (18.1)
Smoking	Yes	23 (32.9)	26 (36.1)	0.166	0.683
	No	47 (67.1)	46 (63.9)
Chemotherapy	Yes	42 (60.0)	38 (52.8)	0.753	0.386
	No	28 (40.0)	34 (47.2)

T-test for age, total bilirubin, unconjugated bilirubin, χ² for gender, degree of tumour differentiation, tumour diameter, tumour location, presence of lymph node metastasis, pathological tumour, node, and metastasis stage, smoking, whether chemotherapy. TBIL: Total bilirubin; UCB: Unconjugated bilirubin; TNM: Tumor, node, and metastasis.

Table 3 Cox regression analysis affecting the prognosis of colorectal cancer patients

Variable		Univariate analysis			Multivariate analysis
		HR	95%CI	P value	HR	95%CI	P value
Age (yr)		1.017	0.989-1.046	0.234	-
Sex	Male
	Female	0.805	0.468-1.384	0.433	-
Grade	High	1			1
	Middle	4.664	1.888-11.521	0.001	2.619	0.939-7.303	0.066
	Low	39.435	16.469-94.427	< 0.001	22.873	7.092-73.769	< 0.001
Diameter	< 5 cm
	≥ 5 cm	2.287	1.315-3.980	0.003	0.927	0.494-1.741	0.814
Lymph node metastasis	No
	Yes	17.672	7.815-39.963	< 0.001	9.129	1.157-73.485	0.036
TNM	Ⅰ	1			1
	Ⅱ	7.235	3.023-17.315	< 0.001	0.998	0.121-8.218	0.999
	Ⅲ	19.778	8.461-46.235	< 0.001	1.124	0.125-10.088	0.917
Smoking	No
	Yes	2.357	1.424-3.093	0.001	0.800	0.444-1.442	0.458
TBIL (μmol/L)	≤ 13.45
	> 13.45	0.282	0.160-0.495	< 0.001	0.360	0.159-0.812	0.014
UCB (μmol/L)	≤ 10.75
	> 10.75	0.178	0.093-0.344	< 0.001	0.986	0.385-2.526	0.977

TBIL: Total bilirubin; UCB: Unconjugated bilirubin; TNM: Tumour, node, and metastasis; CI: Confidence interval; HR: Hazard Ratio.