Background: Hepatocellular carcinoma (HCC) is a common indication for liver transplantation (LT), but post-LT tumor recurrence remains a concern. Early post-LT immunosuppression is suggested to affect recurrence risk. We evaluated the impact on HCC recurrence of an immunosuppression protocol introduced in 2010 with interleukin-2 receptor antibody (IL-2RA) induction and delayed-introduction of reduced-dose tacrolimus with mycophenolate.
Methods: We included consecutive HCC patients transplanted 2000-2017 in Gothenburg. The impact on HCC recurrence of IL-2RA induction and mean tacrolimus trough concentration during the first 20 post-LT days was analyzed by multivariable Cox regression and propensity score-adjusted analyses.
Results: The study comprised 235 patients (mean age 57 yrs, men 80%, mean MELD 13, within Milan criteria 57%). The cumulative 5-yr HCC recurrence rate among patients transplanted before and after 2010 were 28.6% and 19.7%, respectively. IL-2RA induction had no independent effect on HCC recurrence. High tacrolimus exposure (mean 20-day tacrolimus concentration ≥8ng/mL) was associated with increased HCC recurrence risk on univariable analysis (HR 2.22, 95% CI 1.23-4.01, p = .008), but was non-significant on multivariable analysis (p = .17). Outside Milan criteria, high tacrolimus exposure was significant for HCC recurrence (HR 3.68, 95% CI 1.34-10.11, p = .012) independently of tumor characteristics and AFP level. This was confirmed on multivariable propensity score-adjusted analysis.
Conclusions: Reduced early tacrolimus exposure, facilitated by IL-2RA induction, was associated with reduced risk for HCC recurrence among patients outside Milan criteria. Prospective studies are needed to confirm if early tacrolimus-minimization strategies can help reduce HCC recurrence rates and help extend transplant criteria.
Keywords: HCC; Tacrolimus; basiliximab; interleukin-2 receptor antibody; recurrence.