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

BACKGROUND: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: 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.