Lower Alpha-Fetoprotein Threshold of 500 ng/mL for Liver Transplantation May Improve Posttransplant Outcomes in Patients With Hepatocellular Carcinoma.

Abstract

Under current United Network for Organ Sharing (UNOS) policy, patients with hepatocellular carcinoma (HCC) and alpha-fetoprotein (AFP) levels ≥1000 ng/mL are required to show a reduction in AFP level to <500ng/mL before liver transplantation (LT). However, effects of AFP reduction on post-LT HCC outcomes among patients with HCC with moderately elevated AFP levels between 100 and <1000ng/mL are unclear. Adults in the UNOS registry who underwent LTs from January 2005 to September 2015 with initial AFP levels of 100 to 999ng/mL at listing for Model for End-Stage Liver Disease exceptions were included. Primary predictor was AFP level at LT, categorized as <100, 100 to 499, or ≥500ng/mL, and patients with only 1 recorded pre-LT AFP value (AFP 1-value). Survival was compared using the Kaplan-Meier curve method. Factors associated with post-LT survival and HCC recurrence were assessed in a multivariable Cox regression model. Among 1766 included patients, 50.2% had AFP 1-value, followed by 24.7%, 18.9%, and 6.2% with AFP levels <100, 100 to 499, and ≥500ng/mL, respectively. The 5-year post-LT survival rate was lowest in the AFP ≥500 category, at 56.1%, compared with 72.7%, 70.4%, and 65.6% in the AFP <100, 100 to 499ng/mL, and AFP 1-value categories, respectively. In multivariable analysis, AFP ≥500 ng/mL at LT was associated with a greater risk of post-LT death (hazard ratio [HR], 1.5; 95% confidence interval [CI], 1.1-2.1) and HCC recurrence (HR, 1.9; 95% CI, 1.1-3.1) when compared with the AFP <100ng/mL category; other significant variables included donor risk index, age, race/ethnicity, Child-Turcotte-Pugh class, and tumor diameter. Among AFP levels ≥500 ng/mL at LT, 40.4% had AFP levels ≥1000, but no difference in post-LT survival or recurrence was seen between those patients with AFP levels < or ≥1000ng/mL. Mandating AFP <500 ng/mL at LT for all patients, not only for those with initial AFP levels ≥1000ng/mL, may improve post-LT outcomes and can be considered in future UNOS policy.