Competing risk analysis on outcome after hepatic resection of hepatocellular carcinoma in cirrhotic patients

Table 1 Characteristics of the study population of cirrhotic patients, belonging to Child - Pugh class A, submitted to curative hepatectomy of hepatocellular carcinoma n (%)

	n = 864
Age (yr)	67 (61- 72)
≥ 67 yr	432 (50.0)
Gender male	678 (78.5)
Anti-HCV positive	538 (62.3)
HBsAg positive	197 (22.8)
Alcohol/other	120 (13.9)
Creatinine (mg/dL)	0.90 (0.80-1.04)
Albumin (g/L)	4.0 (3.7-4.3)
Bilirubin (mg/dL)	0.85 (0.64-1.19)
INR	1.13 (1.07-1.22)
Platelet count (× 103/mL)	142 (102-186)
< 100.000/mL	202 (23.4)
MELD score	9 (8-10)
< 9	428 (49.5)
9-10	298 (34.5)
> 10	138 (16.0)
Oesophageal varices	216 (25.0)
Tumour size (cm)	3.5 (2.3-5.0)
Single nodule	676 (78.2)
UNOS Stage
T1	84 (9.7)
T2	527 (61.0)
T3	237 (27.4)
T4a	16 (1.9)
Extension of hepatectomy
Wedge/segmentectomy	625 (72.3)
Bisegmentectomy	146 (16.9)
Three or more segments	93 (10.8)

Continuous variables are reported as medians and interquartile ranges. Tumour features are radiological: 610 patients were within Milan criteria (70.6%). UNOS: United Network for Organ Sharing.

Table 2 Cumulative incidence of death from tumour recurrence and from liver failure resulting from competing risk analysis

	Death from tumour recurrence			Death from liver failure
	1-year (%)	3-year (%)	5-year (%)	1-year (%)	3-year (%)	5-year (%)
Age (yr)		P = 0.915			P = 0.267
< 67	3.8 (0.9)	19.9 (2.2)	28.1 (2.6)	4.5 (1.0)	6.2 (1.2)	7.8 (1.4)
≥ 67	3.2 (0.8)	14.7 (1.9)	28.1 (2.8)	4.3 (1.0)	6.7 (1.3)	10.5 (1.8)
Gender		P = 0.738			P = 0.287
Male	3.6 (0.7)	17.7 (1.7)	27.7 (2.1)	4.2 (0.8)	6.6 (1.0)	8.5 (1.2)
Female	3.4 (1.4)	15.4 (2.9)	28.2 (4.1)	5.0 (1.6)	7.2 (1.9)	11.1 (2.8)
Hepatitis C infection		P = 0.838			P = 0.032
Positive	3.7 (0.8)	15.9 (1.8)	27.4 (2.4)	5.3 (1.0)	7.5 (1.2)	10.9 (1.6)
Negative	3.2 (1.0)	19.3 (2.5)	28.3 (3.1)	2.8 (0.9)	4.7 (1.2)	5.9 (1.5)
Portal hypertension1		P = 0.515			P = 0.029
Absent	3.6 (0.8)	17.6 (1.8)	27.2 (2.3)	3.3 (0.8)	5.1 (1.0)	6.9 (1.2)
Present	3.3 (1.0)	16.5 (2.3)	28.8 (3.2)	6.2 (1.4)	8.9 (1.7)	12.9 (2.2)
MELD score		P = 0.760			P = 0.001
< 9	4.2 (1.0)	16.7 (2.0)	27.7 (2.8)	1.9 (0.7)	3.3 (0.9)	5.2 (1.3)
9-10	2.5 (0.9)	17.7 (2.5)	27.8 (3.2)	4.7 (1.2)	6.0 (1.4)	10.2 (2.1)
> 10	3.6 (1.6)	17.3 (3.6)	27.7 (4.7)	11.0 (2.7)	16.6 (3.2)	17.9 (3.4)
UNOS T-stage		P = 0.002			P = 0.597
T1	1.0 (0.0)	7.6 (0.2)	14.5 (0.7)	1.2 (1.0)	3.2 (2.3)	10.6 (4.6)
T2	3.0 (0.7)	15.4 (1.8)	25.0 (2.4)	4.1 (0.9)	6.7 (1.2)	8.7 (1.4)
T3-T4a	5.8 (1.5)	26.3 (3.0)	34.6 (3.6)	6.0 (1.5)	7.8 (1.7)	9.3 (2.0)
Hepatectomy extension		P = 0.042			P = 0.052
Wedge/segmentectomy	3.2 (0.7)	15.2 (1.6)	26.7 (2.3)	3.0 (0.7)	5.5 (1.0)	8.7 (1.4)
Two or more segments	4.4 (1.4)	22.3 (2.9)	30.7 (3.5)	8.1 (1.8)	9.0 (1.9)	10.3 (2.1)

Standard errors are reported in parentheses.

¹Defined as presence of oesophageal varices and/or platelet count < 100000/mL. MELD: Model for End-stage Liver Disease; UNOS: United Network for Organ Sharing.

Table 3 Results from multivariable competing risk regression models

	Sub-Hazard ratio	95%CI	P value
Death for tumour recurrence
UNOS T-stage (T1 vs T2 vs T3-4a)	1.59	1.21-2.09	0.001
Removal of more than one segment	1.08	0.76-1.51	0.667
Death for liver failure
Hepatitis C (positive vs negative)	1.79	1.01-3.17	0.046
Portal hypertension (present vs absent)	1.84	1.08-3.12	0.024
MELD class (< 9 vs 9-10 vs > 10)	2.21	1.59-3.07	0.001
Removal of more than one segment	1.89	1.11-3.21	0.019

The multivariable model included variables with a P < 0.10 of Table 2. A backward stepwise variable-selection process was selected to obtain estimates of non-significant variables (Removal of more than one segment for death from tumour recurrence; P = 0.667). Sub-hazard ratios were used together with the baseline cumulative sub-hazard function (data not reported) to predict individual risks of death for liver failure and for tumour recurrence reported in Figure 2.