Is there an ideal cutoff for α-fetoprotein as an exclusion criterion for liver transplantation?

Abstract

TO THE EDITORS:Hameed et al.1 published a study on a-fetoprotein (AFP) as an exclusion criterion for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). We believe that they used a very high cutoff for AFP (>1000 ng/mL). Because of the retrospective nature of the study and the small sample with elevated AFP levels, we believe that it is difficult to take this value as definitive.We conducted a retrospective study of 768 patients undergoing LT between 1997 and 2010 (206 with a histological diagnosis of HCC). The leading cause of cirrhosis was also hepatitis C. Patients were followed for up to 173 months (mean 5 49.8 months). The survival of LT recipients at 1, 3, 5, and 14 years was 78.6%, 65.4%, 60.5%, and 38.7%, respectively. Survival was higher in the recurrence-free group versus patients with HCC recurrence (P < 0.001), and AFP levels correlated with tumor recurrence. At the 5-year posttransplant follow-up, the rate of HCC recurrence in patients with AFP levels < 50 ng/mL was 13.1%, whereas the rates were 29.4% for AFP levels of 50 to 200 ng/mL and 36.8% for AFP levels >200 ng/mL (P 5 0.002). A univariate analysis of risk factors for HCC recurrence revealed a hazard ratio (HR) of 3.85 [95% confidence interval (CI) 5 1.66-8.93, P 5 0.002] for AFP levels 200 ng/mL. Other risk factors for recurrence were the number of tumors (HR 5 1.37, 95% CI 5 1.20-1.56, P < 0.001), the degree of differentiation (HR 5 2.28, 95% CI 5 1.18-4.39, P 5 0.014), vascular invasion (HR 5 4.82, 95% CI 5 2.08-11.17, P < 0.001), and the presence of satellite nodules (HR 5 3.33, 95% CI 5 1.66-6.68, P 5 0.001). In a multivariate analysis, only AFP levels > 200 ng/mL remained a risk factor with an HR of 3.32 (95% CI 5 1.40-7.91, P 5 0.007).Despite the diversity of values reported in the literature, 2-4 we believe that very high levels of AFP (>1000 ng/mL) are restrictive because of the small number of patients who meet this criterion and the need for a better standard for organ allocation.