Characterizing the Risk of False-Positive Hepatocellular Carcinoma in Recipients Transplanted With T2 MELD Exceptions.

Abstract

Patients with hepatocellular carcinoma (HCC) can receive Model for End-Stage Liver Disease (MELD) exception points to increase waitlist priority for liver transplantation. This process does not require a biopsy and is based on radiologic criteria. However, imaging modalities are imperfect, and some will ultimately have no HCC on explant. This was a retrospective cohort study using national explant pathology data from 2012 to 2015. False-positive HCC was defined as answering "no" to the question: "was evidence of HCC (viable or nonviable) found in the explant?" in patients with T2 MELD exceptions. Four thousand one hundred seventeen patients received T2 MELD exceptions, of which 245 (6%) had false-positive HCC. Maximal tumor diameter of 3 to 5 cm and serum α fetoprotein (AFP) greater than 100 ng/mL at transplant yielded a 50% lower risk of false-positive HCC (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.27-0.73 and OR, 0.57; 95% CI, 0.37-0.88, respectively). Recipients with immune-mediated liver disease were twice as likely to have no HCC on explant (OR, 2.12; 95% CI, 1.18-3.83) and had a predicted probability of false positive HCC greater than 10% regardless of largest tumor size or AFP. Significant among-center variability in the rate of false-positive HCC was seen. The risk of false-positive HCC is markedly higher in certain groups, such that biopsy may be warranted before T2 MELD exception point approval. Transplant centers with high false-positive HCC rates may benefit from greater oversight.