Busuttil, Ronald W

HCC recurrence following liver transplantation (LT) is highly morbid and occurs despite strict patient selection criteria. Individualized prediction of post-LT HCC recurrence risk remains an important need. Clinico-radiologic and pathologic data of 4981 patients with HCC undergoing LT from the US Multicenter HCC Transplant Consortium (UMHTC) were analyzed to develop a REcurrent Liver cAncer Prediction ScorE (RELAPSE). Multivariable Fine and Gray competing risk analysis and machine learning algorithms (Random Survival Forest and Classification and Regression Tree models) identified variables to model HCC recurrence. RELAPSE was externally validated in 1160 HCC LT recipients from the European Hepatocellular Cancer Liver Transplant study group. Of 4981 UMHTC patients with HCC undergoing LT, 71.9% were within Milan criteria, 16.1% were initially beyond Milan criteria with 9.4% downstaged before LT, and 12.0% had incidental HCC on explant pathology. Overall and recurrence-free survival at 1, 3, and 5 years was 89.7%, 78.6%, and 69.8% and 86.8%, 74.9%, and 66.7%, respectively, with a 5-year incidence of HCC recurrence of 12.5% (median 16 months) and non-HCC mortality of 20.8%. A multivariable model identified maximum alpha-fetoprotein (HR = 1.35 per-log SD, 95% CI,1.22–1.50, p < 0.001), neutrophil-lymphocyte ratio (HR = 1.16 per-log SD, 95% CI,1.04–1.28, p < 0.006), pathologic maximum tumor diameter (HR = 1.53 per-log SD, 95% CI, 1.35–1.73, p < 0.001), microvascular (HR = 2.37, 95%–CI, 1.87–2.99, p < 0.001) and macrovascular (HR = 3.38, 95% CI, 2.41–4.75, p < 0.001) invasion, and tumor differentiation (moderate HR = 1.75, 95% CI, 1.29–2.37, p < 0.001; poor HR = 2.62, 95% CI, 1.54–3.32, p < 0.001) as independent variables predicting post-LT HCC recurrence (C-statistic = 0.78). Machine learning algorithms incorporating additional covariates improved prediction of recurrence (Random Survival Forest C-statistic = 0.81). Despite significant differences in European Hepatocellular Cancer Liver Transplant recipient radiologic, treatment, and pathologic characteristics, external validation of RELAPSE demonstrated consistent 2- and 5-year recurrence risk discrimination (AUCs 0.77 and 0.75, respectively). We developed and externally validated a RELAPSE score that accurately discriminates post-LT HCC recurrence risk and may allow for individualized post-LT surveillance, immunosuppression modification, and selection of high-risk patients for adjuvant therapies.

Background and Aims The Organ Procurement and Transplantation Network recently approved liver transplant (LT) prioritization for patients with hepatocellular carcinoma (HCC) beyond Milan Criteria (MC) who are down‐staged (DS) with locoregional therapy (LRT). We evaluated post‐LT outcomes, predictors of down‐staging, and the impact of LRT in patients with beyond‐MC HCC from the U.S. Multicenter HCC Transplant Consortium (20 centers, 2002‐2013). Approach and Results Clinicopathologic characteristics, overall survival (OS), recurrence‐free survival (RFS), and HCC recurrence (HCC‐R) were compared between patients within MC (n = 3,570) and beyond MC (n = 789) who were down‐staged (DS, n = 465), treated with LRT and not down‐staged (LRT‐NoDS, n = 242), or untreated (NoLRT‐NoDS, n = 82). Five‐year post‐LT OS and RFS was higher in MC (71.3% and 68.2%) compared with DS (64.3% and 59.5%) and was lowest in NoDS (n = 324; 60.2% and 53.8%; overall P < 0.001). DS patients had superior RFS (60% vs. 54%, P = 0.043) and lower 5‐year HCC‐R (18% vs. 32%, P < 0.001) compared with NoDS, with further stratification by maximum radiologic tumor diameter (5‐year HCC‐R of 15.5% in DS/<5 cm and 39.1% in NoDS/>5 cm, P < 0.001). Multivariate predictors of down‐staging included alpha‐fetoprotein response to LRT, pathologic tumor number and size, and wait time >12 months. LRT‐NoDS had greater HCC‐R compared with NoLRT‐NoDS (34.1% vs. 26.1%, P < 0.001), even after controlling for clinicopathologic variables (hazard ratio [HR] = 2.33, P < 0.001) and inverse probability of treatment‐weighted propensity matching (HR = 1.82, P < 0.001). Conclusions In LT recipients with HCC presenting beyond MC, successful down‐staging is predicted by wait time, alpha‐fetoprotein response to LRT, and tumor burden and results in excellent post‐LT outcomes, justifying expansion of LT criteria. In LRT‐NoDS patients, higher HCC‐R compared with NoLRT‐NoDS cannot be explained by clinicopathologic differences, suggesting a potentially aggravating role of LRT in patients with poor tumor biology that warrants further investigation.