Humar, Abhinav

Living donor liver transplantation (LDLT) is an established therapy with curative intent for pediatric and adult patients with acute liver failure and end-stage liver disease. Donor safety remains paramount and commences during preoperative evaluation and assessment. Given the importance of the topic, the International Liver Transplantation Society and International Living Donor Liver Transplantation Group consensus conference on Living Liver Donor Safety was convened in March 2025 (Toronto, Canada). Recommendations were based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system for assessment of recommendations, and the Danish model of consensus was followed. This report presents 28 recommendations from the working group focused on addressing clinically relevant questions related to the preoperative aspects of living donor safety including assessment of donor acceptability (age, body mass index and hepatic steatosis; medical conditions and contraindications), medical and surgical workup (liver function and procoagulant workup; anatomical considerations and safe remnant), and psychosocial evaluation (timing and team; underlying conditions; non-directed, paired, and anonymous directed donors; urgent living donor workups for acute liver failure).

Introduction: Liver transplantation (LT) provides significant survival benefits to patients with unresectable HCC. In the United States, organ allocation policies for HCCs within the United Network for Organ Sharing criteria do not prioritize patients based on their differences in oncological characteristics. This study assessed whether transplant-associated survival benefits (TASBs) vary among patients with different tumor burden scores (TBS) measured at the time of listing. Methods: We analyzed data from adults applying for HCC MELD exception points between 2002 and 2019, with follow-up until December 2023, using the Scientific Registry of Transplant Recipients. TBS was determined based on the largest tumor diameter and number of HCCs. Patients were categorized into low (≤3), intermediate (3.1–5), and high (>5) TBS groups. TASB was measured as the difference in 5-year survival with and without LT. Results: This study included 36,634 LT candidates. High-TBS patients had higher waitlist dropout rates and marginally lower post-transplant survival, resulting in a significantly greater TASB. The 5-year TASB for the low, intermediate, and high TBS groups were 15.7, 22.1, and 25.0 months, respectively. The adjusted survival benefit expressed in 5-year survival differences was 21.9%, 34.5%, and 39.4% in the low, intermediate, and high TBS groups, respectively ( p <0.001). Conclusions: Higher TBS during listing correlates with greater LT benefits for patients with unresectable HCC within UNOS criteria. We conclude that organ allocation policies in the United States should prioritize patients with high TBS due to their increased risk of dropout and comparable post-transplant survival when compared to patients with less advanced tumors.

Liver transplantation (LT) is a highly effective treatment for carefully selected patients with hepatocellular carcinoma (HCC). In this review, we explored the development of LT selection criteria and organ allocation policies, comparing original data to underscore their historical progression into the intricate task of quantitatively estimating pre- and post-LT survivals. We emphasized the role of biomarkers such as serum alpha-fetoprotein, Des-gamma-carboxy-prothrombin, circulating tumor cells, and circulating tumor DNA in predicting patient outcomes. Additionally, we examined the transplant-associated survival benefits and the difficulties in accurately calculating these benefits. We also reviewed recent advancements in targeted therapy and checkpoint inhibitors for advanced, inoperable HCC and projected their integration into LT for HCC. We further discussed the growing use of living donor liver transplants in the United States and compared its outcomes with those of deceased donor liver transplants. Furthermore, we examined the progress in machine perfusion techniques, which have shown potential in improving patient outcomes and enlarging the donor pool. These advancements present opportunities to enhance LT patient survivals, refine selection criteria, establish new priority metrics, develop innovative bridging and downstaging strategies, and formulate redesigned LT strategies for HCC treatments.

Background. During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS). Methods. A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India. Results. It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion. Conclusions. Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

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 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.