Sudan, Debra L.

Background. The adoption of technical variant grafts has expanded the donor pool for pediatric liver transplantation, but it also poses a risk of portal vein thrombosis (PVT). This study evaluated risk and prognostic factors of PVT in children undergoing liver transplantation with technical variant grafts. Methods. A total of 3137 pediatric patients from 19 centers were included: 470 received split/reduced deceased donor grafts and 2667 received living donor grafts. Multivariable logistic regression was used to identify risk factors, whereas time-dependent Cox models were used to assess the impact on survival. Results. PVT occurred in 102 patients (3.3%) and was associated with increased mortality (adjusted hazard ratio, 2.86; 95% confidence interval [CI], 1.13-7.25; P = 0.027) and graft loss (adjusted hazard ratio, 9.97; 95% CI, 4.90-20.3; P < 0.001). Risk factors included younger age, lower weight, higher Pediatric End-Stage Liver Disease score, longer cold ischemia and operation times, higher graft-to-recipient weight ratio, increased red blood cell transfusions, and biliary atresia. After adjusting for center, lower weight (odds ratio, 0.84 per kg; 95% CI, 0.71-1.00; P = 0.047) and biliary atresia (odds ratio, 2.34; 95% CI, 1.10-5.00; P = 0.027) remained predictors. Five-year patient (88.4% versus 93.1%) and graft survival (82.7% versus 96.3%) were significantly inferior in patients with PVT. Conclusions. Low-weight children with biliary atresia constituted a high-risk group, highlighting the necessity for early detection and management.

Objective: To compare conventional low-temperature storage of transplant donor livers [static cold storage (SCS)] with storage of the organs at physiological body temperature [normothermic machine perfusion (NMP)]. Background: The high success rate of liver transplantation is constrained by the shortage of transplantable organs (eg, waiting list mortality >20% in many centers). NMP maintains the liver in a functioning state to improve preservation quality and enable testing of the organ before transplantation. This is of greatest potential value with organs from brain-dead donor organs (DBD) with risk factors (age and comorbidities), and those from donors declared dead by cardiovascular criteria (donation after circulatory death). Methods: Three hundred eighty-three donor organs were randomized by 15 US liver transplant centers to undergo NMP (n = 192) or SCS (n = 191). Two hundred sixty-six donor livers proceeded to transplantation (NMP: n = 136; SCS: n = 130). The primary endpoint of the study was “early allograft dysfunction” (EAD), a marker of early posttransplant liver injury and function. Results: The difference in the incidence of EAD did not achieve significance, with 20.6% (NMP) versus 23.7% (SCS). Using exploratory, “as-treated” rather than “intent-to-treat,” subgroup analyses, there was a greater effect size in donation after circulatory death donor livers (22.8% NMP vs 44.6% SCS) and in organs in the highest risk quartile by donor risk (19.2% NMP vs 33.3% SCS). The incidence of acute cardiovascular decompensation at organ reperfusion, “postreperfusion syndrome,” as a secondary outcome was reduced in the NMP arm (5.9% vs 14.6%). Conclusions: NMP did not lower EAD, perhaps related to the inclusion of lower-risk liver donors, as higher-risk donor livers seemed to benefit more. The technology is safe in standard organ recovery and seems to have the greatest benefit for marginal donors.

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.

NAFLD will soon be the most common indication for liver transplantation (LT). In NAFLD, HCC may occur at earlier stages of fibrosis and present with more advanced tumor stage, raising concern for aggressive disease. Thus, adult LT recipients with HCC from 20 US centers transplanted between 2002 and 2013 were analyzed to determine whether NAFLD impacts recurrence-free post-LT survival. Five hundred and thirty-eight (10.8%) of 4981 total patients had NAFLD. Patients with NAFLD were significantly older (63 vs. 58, p<0.001), had higher body mass index (30.5 vs. 27.4, p<0.001), and were more likely to have diabetes (57.3% vs. 28.8%, p<0.001). Patients with NAFLD were less likely to receive pre-LT locoregional therapy (63.6% vs. 72.9%, p<0.001), had higher median lab MELD (15 vs. 13, p<0.001) and neutrophil-lymphocyte ratio (3.8 vs. 2.9, p<0.001), and were more likely to have their maximum pre-LT alpha fetoprotein at time of LT (44.1% vs. 36.1%, p<0.001). NAFLD patients were more likely to have an incidental HCC on explant (19.4% vs. 10.4%, p<0.001); however, explant characteristics including tumor differentiation and vascular invasion were not different between groups. Comparing NAFLD and non-NAFLD patients, the 1, 3, and 5-year cumulative incidence of recurrence (3.1%, 9.1%, 11.5% vs. 4.9%, 10.1%, 12.6%, p=0.36) and recurrence-free survival rates (87%, 76%, and 67% vs. 87%, 75%, and 67%, p=0.97) were not different. In competing risks analysis, NAFLD did not significantly impact recurrence in univariable (HR: 0.88, p=0.36) nor in adjusted analysis (HR: 0.91, p=0.49). With NAFLD among the most common causes of HCC and poised to become the leading indication for LT, a better understanding of disease-specific models to predict recurrence is needed. In this NAFLD cohort, incidental HCCs were common, raising concerns about early detection. However, despite less locoregional therapy and high neutrophil-lymphocyte ratio, explant tumor characteristics and post-transplant recurrence-free survival were not different compared to non-NAFLD patients.

The incidence of hepatocellular carcinoma (HCC) is growing in the United States, especially among the elderly. Older patients are increasingly receiving transplants as a result of HCC, but the impact of advancing age on long‐term posttransplant outcomes is not clear. To study this, we used data from the US Multicenter HCC Transplant Consortium of 4980 patients. We divided the patients into 4 groups by age at transplantation: 18 to 64 years (n = 4001), 65 to 69 years (n = 683), 70 to 74 years (n = 252), and ≥75 years (n = 44). There were no differences in HCC tumor stage, type of bridging locoregional therapy, or explant residual tumor between the groups. Older age was confirmed to be an independent and significant predictor of overall survival even after adjusting for demographic, etiologic, and cancer‐related factors on multivariable analysis. A dose‐response effect of age on survival was observed, with every 5‐year increase in age older than 50 years resulting in an absolute increase of 8.3% in the mortality rate. Competing risk analysis revealed that older patients experienced higher rates of non–HCC‐related mortality (P = 0.004), and not HCC‐related death (P = 0.24). To delineate the precise cause of death, we further analyzed a single‐center cohort of patients who received a transplant as a result of HCC (n = 302). Patients older than 65 years had a higher incidence of de novo cancer (18.1% versus 7.6%; P = 0.006) after transplantation and higher overall cancer‐related mortality (14.3% versus 6.6%; P = 0.03). Even carefully selected elderly patients with HCC have significantly worse posttransplant survival rates, which are mostly driven by non–HCC‐related causes. Minimizing immunosuppression and closer surveillance for de novo cancers can potentially improve the outcomes in elderly patients who received a transplant as a result of HCC.

Background. Desensitization protocols for HLA-incompatible living donor kidney transplantation (ILDKT) vary across centers. The impact of these, as well as other practice variations, on ILDKT outcomes remains unknown. Methods. We sought to quantify center-level variation in mortality and graft loss following ILDKT using a 25-center cohort of 1358 ILDKT recipients with linkage to Scientific Registry of Transplant Recipients for accurate outcome ascertainment. We used multilevel Cox regression with shared frailty to determine the variation in post-ILDKT outcomes attributable to between-center differences and to identify any center-level characteristics associated with improved post-ILDKT outcomes. Results. After adjusting for patient-level characteristics, only 6 centers (24%) had lower mortality and 1 (4%) had higher mortality than average. Similarly, only 5 centers (20%) had higher graft loss and 2 had lower graft loss than average. Only 4.7% of the differences in mortality (P < 0.01) and 4.4% of the differences in graft loss (P < 0.01) were attributable to between-center variation. These translated to a median hazard ratio of 1.36 for mortality and 1.34 of graft loss for similar candidates at different centers. Post-ILDKT outcomes were not associated with the following center-level characteristics: ILDKT volume and transplanting a higher proportion of highly sensitized, prior transplant, preemptive, or minority candidates. Conclusions. Unlike most aspects of transplantation in which center-level variation and volume impact outcomes, we did not find substantial evidence for this in ILDKT. Our findings support the continued practice of ILDKT across these diverse centers.

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.

Objective: The aim of the study was to determine the rate, predictors, and impact of complete pathologic response (cPR) to pretransplant locoregional therapy (LRT) in a large, multicenter cohort of hepatocellular carcinoma (HCC) patients undergoing liver transplantation (LT). Background: LRT is used to mitigate waitlist dropout for patients with HCC awaiting LT. Degree of tumor necrosis found on explant has been associated with recurrence and overall survival, but has not been evaluated in a large, multicenter study. Methods: Comparisons were made among patients receiving pre-LT LRT with (n = 802) and without (n = 2637) cPR from the United States Multicenter HCC Transplant Consortium (UMHTC), and multivariable predictors of cPR were identified using logistic regression. Results: Of 3439 patients, 802 (23%) had cPR on explant. Compared with patients without cPR, cPR patients were younger; had lower Model for End-stage Liver Disease (MELD) scores, AFP levels, and neutrophil–lymphocyte ratios (NLR); were more likely to have tumors within Milan criteria and fewer LRT treatments; and had significantly lower 1-, 3-, and 5-year incidence of post-LT recurrence (1.3%, 3.5%, and 5.2% vs 6.2%, 13.5%, and 16.4%; P < 0.001) and superior overall survival (92%, 84%, and 75% vs 90%, 78%, and 68%; P < 0.001). Multivariable predictors of cPR included age, sex, liver disease diagnosis, MELD, AFP, NLR, radiographic Milan status, and number of LRT treatments (C-statistic 0.67). Conclusions: For LT recipients with HCC receiving pretransplant LRT, achieving cPR portends significantly lower posttransplant recurrence and superior survival. Factors predicting cPR are identified, which may help prioritize patients and guide LRT strategies to optimize posttransplant cancer outcomes.