Predictive value of nodule size and differentiation in HCC recurrence after liver transplantation

Liver transplantation (LT) is considered the best treatment option for HCC patients with cirrhosis. However, the scarce availability of liver donors and the risk of dropout from the waiting list due to the tumor progression severely limit LT for HCC. In this study, we evaluate the survival and recurrence in a cohort of patients undergoing LT for HCC fulfilling "Milan Criteria" (MC) pre-LT. In this study, we propose the development of a new prognostic score which could improve the accuracy in predicting recurrence post-LT.

Between 1997 and 2011, out of 1010 LT performed in our unit, 131 patients had T2 staged HCC (inside MC). The prognostic model predicting HCC recurrence post-LT was derived from Cox regression analysis. The performance of this model was validated in an external cohort of 198 HCC patients transplanted at another center.

Overall survival at 1-3-5 years was 87%, 74.4%, 68.2%, whereas recurrence-free survival was 94.1%, 81.4%, 77.6%, respectively. Predictive factors for recurrence-free survival included high tumor grading (HR 5.01; p = 0.006) and tumor diameter (HR 1.46; p = 0.045). According to this model, the estimated relative risk of HCC recurrence after LT is given by this formula: 0.382 × (Tumor size [cm]) + 1.613 × (if Grading 3-4). The ROC curve was 0.878 (p < 0.001) in predicting HCC recurrence.

In conclusion, our study showed that the use of this new prognostic score, taking into account maximal tumor diameter and tumor differentiation, improves the accuracy of Milan criteria in predicting HCC recurrence.