Tumour size and differentiation in predicting recurrence of hepatocellular carcinoma after liver transplantation: external validation of a new prognostic score.

Background: A new prognostic score including tumour differentiation--establishing two groups of patients: group A with >3 points and group B with >4 points--improved the accuracy of the Milan criteria in predicting recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) in a large multicentre study (Decaens 2007).

Aim: The aim of this study was to validate the new score in our HCC cohort.

Methods: The study involved 100 consecutive patients with mean age 55 years (range 31-68 years) (M/F: 88/22) transplanted for known HCC: 60 unifocal and 40 multifocal (2-3 nodules in 32 and >or=4 nodules in 8) at pre-LT imaging. Survival differences were analysed by log-rank test. Patient/tumour variables before LT and tumour differentiation at explant were assessed by univariate/multivariate analysis.

Results: Median follow-up was 29 months (range 1-145 months). HCC recurrence was recorded in 18 patients. Five-year recurrence-free survival rate was 67 +/- 7%. Patient survival at 3 months was 84 +/- 4% and at 5 years was 45 +/- 6%. Both recurrence-free survival and patient survival were not significantly different between groups A and B. Diameter of largest nodule was the sole pre-LT variable independently associated with recurrence [odd ratio (OR) 1.07; 95% confidence interval (CI) 1.01-1.12; P = 0.012]. Recurrence-free survival was significantly better in patients with diameter <30 mm compared with those with larger nodules (P = 0.0229). Number of nodules and tumour differentiation did not influence recurrence. There were three HCC recurrences with largest nodule size <30 mm, seven recurrences between 30-40 mm, and eight recurrences >40 mm.

Conclusion: Tumour differentiation did not add significantly to prediction of HCC recurrence in our cohort. Conversely, diameter of the largest nodule remained a significant risk for recurrence.