Alpha-fetoprotein and 18F-FDG standard uptake value predict tumor recurrence after liver transplantation for hepatocellular carcinoma with portal vein tumor thrombosis: Preliminary experience

Abstract

Background: Portal vein tumor thrombosis (PVTT) is regarded as a contraindication for liver transplantation (LT) in hepatocellular carcinoma (HCC). However, some of these patients may have a favorable prognosis after LT. In this study, we evaluated the biological behavior of HCC with PVTT using tumor biomarker (alpha-fetoprotein, AFP) and ¹⁸F-FDG positron emission tomography (tumor standard uptake value) to identify a subset of patients who may be suitable for LT.

Methods: Seventy-five HCC-PVTT liver recipients transplanted during February 2016 and June 2018 were analyzed. Different pre-transplant prognostic factors were identified by univariate and multivariate analyses. PVTT status was identified following Vp classification (Vp1-Vp4).

Results: Three-year recurrence-free survival and overall survival rates were 40% and 65.4% in Vp2-Vp3 PVTT patients, 21.4% and 30.6% in Vp4 PVTT patients (P < 0.05). Total tumor diameter >8 cm, pre-transplant AFP level >1000 ng/mL and intrahepatic tumor maximal standard uptake value (SUVmax-tumor >5) were independent risk factors for HCC recurrence and overall survival after LT in Vp2-3 PVTT patients. Low risk patients were defined as total tumor diameter ≤8 cm; or if total tumor diameter more than 8 cm, with both pre-transplant AFP level less than 1000 ng/mL and intrahepatic tumor SUVmax less than 5, simultaneously. Twenty-two Vp2-3 PVTT HCC patients (46.8%) were identified as low risk patients, and their 3-year recurrence-free and overall survival rates were 67.6% and 95.2%, respectively.

Conclusions: Patients with segmental or lobar PVTT and biologically favorable tumors defined by AFP and ¹⁸F-FDG SUVmax might be suitable for LT.

Keywords: Alpha-fetoprotein; Hepatocellular carcinoma; Liver transplantation; Portal vein tumor thrombosis; Standard uptake value.