Impact of Single Viable Hepatocellular Carcinoma ≤ 3 cm on Survival After Liver Transplantation.

BACKGROUND: The risks of recurrent hepatocellular carcinoma (HCC) and HCC-specific mortality post-liver transplant (LT) are influenced by the number and size of viable tumours. This study assesses HCC-specific mortality post-transplant for patients in two groups-those with no viable disease versus single viable tumour ≤ 3 cm, as assessed on most recent imaging prior to transplantation. METHODS: This retrospective cohort study included adult patients transplanted for the indication of HCC between 1998 and 2018 at two Australian centres. Competing risks regression assessed 5-year HCC-specific mortality, with the competing risk of non-HCC-specific mortality. RESULTS: There was a significantly lower 5-year HCC-specific mortality post-transplant for those with no viable disease (n = 152) versus single viable tumour ≤ 3 cm (n = 145) (4.0% vs. 10.5%, SHR 2.72, 95% CI: 1.06-6.98, p = 0.038) on univariable analysis. On multivariable competing risks analysis, the modified Response Evaluation Criteria In Solid Tumour (mRECIST) criteria and higher AFP level at transplant were significant predictors of 5-year HCC specific mortality, with progressive disease (aSHR 16.33, 95% CI: 2.35-113.6, p = 0.005) and stable disease (aSHR 10.26, 95% CI: 1.81-58.2, p = 0.0012) having a higher risk than complete response; whilst the significance of no viable disease versus single viable tumour ≤ 3 cm was not significant on multivariable analysis. CONCLUSIONS: There was a significantly lower 5-year HCC-specific mortality for those with imaging showing no viable disease versus single viable tumour ≤ 3 cm, prior to transplantation. Lower HCC-specific mortality was demonstrated for those with a lower AFP level and those in radiological complete response at time of transplant.