Waitlist Dropout Research Articles

Living Donor Availability Improves Patient Survival in a North American Center: An Intention-to-treat Analysis.

Assess the impact of having a living donor on waitlist outcomes and overall survival through an intention-to-treat analysis. Living-donor liver transplantation (LDLT) offers an alternative to deceased donation in the face of organ shortage. An as-treated analysis revealed that undergoing LDLT, compared to staying on the waiting list, is associated with improved survival, even at Model for End-stage Liver Disease-sodium (MELD-Na) score of 11. Liver transplant candidates listed at the Ajmera Transplant Centre (2000-2021) were categorized as pLDLT (having a potential living donor) or pDDLT (without a living donor). Employing Cox proportional-hazard regression with time-dependent covariates, we evaluated pLDLT's impact on waitlist dropout and overall survival through a risk-adjusted analysis. Of 4,124 candidates, 984 (24%) had potential living donors. The pLDLT group experienced significantly lower overall waitlist dropouts (5.2%vs. 34.4%, P<0.001) and mortality (3.8%vs. 24.4%, P<0.001) compared to the pDDLT group. Possessing a living donor correlated with a 26% decline in the risk of waitlist dropout (adjusted hazard ratio 0.74, 95%CI 0.55-0.99, P=0.042). The pLDLT group also demonstrated superior survival outcomes at 1- (84.9%vs. 80.1%), 5- (77.6%vs. 61.7%), and 10-year (65.6%vs.52.9%) from listing (log-rank P<0.001) with a 35% reduced risk of death (adjusted hazard ratio 0.65, 95%CI 0.56-0.76, P<0.001). Moreover, the predicted hazard ratios consistently remained below 1 across the MELD-Na range 11-26. Having a potential living donor significantly improves survival in end-stage liver disease patients, even with MELD-Na scores as low as 11. This emphasizes the need to promote awareness and adoption of LDLT in liver transplant programs worldwide.

Continuous Risk Score Predicts Waitlist and Post-transplant Outcomes in Hepatocellular Carcinoma Despite Exception Changes

Background and AimsContinuous risk stratification of candidates and urgency-based prioritization have been utilized for liver transplantation (LT) in non-hepatocellular carcinoma (HCC) patients in the United States. Instead, for HCC patients, a dichotomous criterion with exception points is still used. This study evaluated the utility of the hazard associated with LT for HCC (HALT-HCC), an oncological continuous risk score, to stratify waitlist dropout and post-LT outcomes. MethodsA competing risk model was developed and validated using the UNOS database (2012-2021) through multiple policy changes. The primary outcome was to assess the discrimination ability of waitlist dropouts and LT outcomes. The study focused on the HALT-HCC score, compared to other HCC risk scores. ResultsAmong 23,858 candidates, 14,646 (59.9%) underwent LT and 5,196 (21.8%) dropped out of the waitlist. Higher HALT-HCC scores correlated with increased dropout incidence and lower predicted five-year overall survival after LT. HALT-HCC demonstrated the highest AUC values for predicting dropout at various intervals post-listing (0.68 at six months, 0.66 at one year), with excellent calibration (R2=0.95 at six months, 0.88 at one year). Its accuracy remained stable across policy periods and locoregional therapy applications. ConclusionsThis study highlights the predictive capability of the continuous oncological risk score to forecast waitlist dropout and post-LT outcomes in HCC patients, independent of policy changes. The study advocates integrating continuous scoring systems like HALT-HCC in liver allocation decisions, balancing urgency, organ utility, and survival benefit.

An updated analysis of retransplantation following living donor liver transplantation in the United States: Insights from the latest UNOS database.

There is no recent update on the clinical course of retransplantation (re-LT) after living donor liver transplantation (LDLT) in the US using recent national data. The UNOS database (2002-2023) was used to explore patient characteristics in initial LT, comparing deceased donor liver transplantation (DDLT) and LDLT for graft survival (GS), reasons for graft failure, and GS after re-LT. It assesses waitlist dropout and re-LT likelihood, categorizing re-LT cohort based on time to re-listing as acute or chronic (≤ or > 1 mo). Of 132,323 DDLT and 5955 LDLT initial transplants, 3848 DDLT and 302 LDLT recipients underwent re-LT. Of the 302 re-LT following LDLT, 156 were acute and 146 chronic. Primary nonfunction (PNF) was more common in DDLT, although the difference was not statistically significant (17.4% vs. 14.8% for LDLT; p = 0.52). Vascular complications were significantly higher in LDLT (12.5% vs. 8.3% for DDLT; p < 0.01). Acute re-LT showed a larger difference in primary nonfunction between DDLT and LDLT (49.7% vs. 32.0%; p < 0.01). Status 1 patients were more common in DDLT (51.3% vs. 34.0% in LDLT; p < 0.01). In the acute cohort, Kaplan-Meier curves indicated superior GS after re-LT for initial LDLT recipients in both short-term and long-term ( p = 0.02 and < 0.01, respectively), with no significant difference in the chronic cohort. No significant differences in waitlist dropout were observed, but the initial LDLT group had a higher re-LT likelihood in the acute cohort (sHR 1.40, p < 0.01). A sensitivity analysis focusing on the most recent 10-year cohort revealed trends consistent with the overall study findings. LDLT recipients had better GS in re-LT than DDLT. Despite a higher severity of illness, the DDLT cohort was less likely to undergo re-LT.

Pursuing living donor liver transplantation improves outcomes of patients with autoimmune liver diseases: An intention-to-treat analysis.

Living donor liver transplantation (LDLT) offers the opportunity to decrease waitlist time and mortality for patients with autoimmune liver disease (AILD), autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. We compared the survival of patients with a potential living donor (pLDLT) on the waitlist versus no potential living donor (pDDLT) on an intention-to-treat basis. Our retrospective cohort study investigated adults with AILD listed for a liver transplant in our program between 2000 and 2021. The pLDLT group comprised recipients with a potential living donor. Otherwise, they were included in the pDDLT group. Intention-to-treat survival was assessed from the time of listing. Of the 533 patients included, 244 (43.8%) had a potential living donor. Waitlist dropout was higher for the pDDLT groups among all AILDs (pDDLT 85 [29.4%] vs. pLDLT 9 [3.7%], p < 0.001). The 1-, 3-, and 5-year intention-to-treat survival rates were higher for pLDLT versus pDDLT among all AILDs (95.7% vs. 78.1%, 89.0% vs. 70.1%, and 87.1% vs. 65.5%, p < 0.001). After adjusting for covariates, pLDLT was associated with a 38% reduction in the risk of death among the AILD cohort (HR: 0.62, 95% CI: 0.42-0.93 [ p <0.05]), and 60% among the primary sclerosing cholangitis cohort (HR: 0.40, 95% CI: 0.22-0.74 [ p <0.05]). There were no differences in the 1-, 3-, and 5-year post-transplant survival between LDLT and DDLT (AILD: 95.6% vs. 92.1%, 89.9% vs. 89.4%, and 89.1% vs. 87.1%, p =0.41). This was consistent after adjusting for covariates (HR: 0.97, 95% CI: 0.56-1.68 [ p >0.9]). Our study suggests that having a potential living donor could decrease the risk of death in patients with primary sclerosing cholangitis on the waitlist. Importantly, the post-transplant outcomes in this population are similar between the LDLT and DDLT groups.

No Improvement in Intention-to-treat Survival and Increasing Liver Nonutilization Rate During the MELD Era.

Although post liver transplant survival rates have significantly improved during the past 2-3 decades, the trend in intention-to-treat (ITT) survival (survival from waitlist addition) has not been well studied. We conducted a retrospective analysis of Scientific Registry of Transplant Recipients data to determine the trend in ITT survival in liver transplant candidates. Adult (age ≧ 18 y) patients who were on the waitlist between the time period of March 1, 2002, to December 31, 2019 (n = 200 816) and deceased liver donors that were registered between the same time period (n = 152 593) were analyzed. We found a constant increase in posttransplant survival rates; however, the ITT survival rates showed no statistically significant improvement through the study period. We observed significant linear increase in waitlist dropout rates over time. We also observed linear increase in liver nonutilization rate in both entire cases and brain-dead cases. Donor risk index increased significantly over the years; however, it was mostly driven by increase in donation after circulatory death cases; without donation after circulatory death cases, donor risk index was stable throughout the 17 y we observed. The reason of the increased liver nonutilization rate is unclear; however, it is possible that reluctance to use high-risk organ to maintain better posttransplant outcomes contributed to this increase, which also could have led to increase in waitlist dropout rates and no improvements in ITT survival. Further investigation is warranted on the increased nonutilization rates to improve over all contribution of liver transplant to patient care.

AFP-L3 and DCP are superior to AFP in predicting waitlist dropout in HCC patients: Results of a prospective study.

In patients with HCC awaiting liver transplantation (LT), there is a need to identify biomarkers that are superior to AFP in predicting prognosis. AFP-L3 and des-gamma-carboxyprothrombin (DCP) play a role in HCC detection, but their ability to predict waitlist dropout is unknown. In this prospective single-center study commenced in July 2017, 267 HCC patients had all 3 biomarkers obtained at LT listing. Among them, 96.2% received local-regional therapy, and 18.8% had an initial tumor stage beyond Milan criteria requiring tumor downstaging. At listing, median AFP was 7.0ng/mL (IQR 3.4-21.5), median AFP-L3 was 7.1% (IQR 0.5-12.5), and median DCP was 1.0ng/mL (IQR 0.2-3.8). After a median follow-up of 19.3 months, 63 (23.6%) experienced waitlist dropout, while 145 (54.3%) received LT, and 59 (22.1%) were still awaiting LT. Using Cox proportional hazards analysis, AFP-L3≥35% and DCP≥7.5ng/mL were associated with increased waitlist dropout, whereas AFP at all tested cutoffs, including ≥20,≥ 100, and≥250ng/mL was not. In a multivariable model, AFP-L3≥35% (HR 2.25, p =0.04) and DCP≥7.5ng/mL (HR 2.20, p =0.02) remained associated with waitlist dropout as did time from HCC diagnosis to listing ≥ 1 year and increasing MELD-Na score. Kaplan-Meier probability of waitlist dropout within 2 years was 21.8% in those with AFP-L3<35% and DCP<7.5ng/mL, 59.9% with either AFP-L3 or DCP elevated, and 100% for those with both elevated ( p <0.001). In this prospective study, listing AFP-L3% and DCP were superior to AFP in predicting waitlist dropout with the combination of AFP-L3≥35% and DCP≥7.5ng/mL associated with a 100% risk of waitlist dropout, thus clearly adding prognostic value to AFP alone.

Balancing Waitlist Dropout in Pancreas Transplantation

The time a patient spends on the waiting list for a Simultaneous Pancreas-Kidney (SPK) transplant depends on several donor and recipient-specific factors. The average wait-list time for SPK in the United States has been about 1 to 3 years, significantly shorter than the average wait time for kidney-only transplantation. A single-center retrospective analysis of SPK waitlisted candidates was performed to determine the implication of wait-list time on dropout from the wait-list due to death or poor health. We analyzed all deceased donor Simultaneous Pancreas-Kidney wait-listed candidates between Jan 1994 and June 2021. Waitlisted candidates who got transplanted (TG) were compared to those who dropped out from the wait list due to death or poor health (DPHG). In the study period, 297 candidates were waitlisted for SPK transplants. Eight candidates were removed, as transplantation was not needed due to improvement in health while on the waiting list. Fourteen wait-listed candidates transferred to another center were also excluded from the study group. Two hundred and thirty wait-listed candidates were transplanted (TG). Forty-five patients were delisted due to death or poor health (DPHG). The mean body mass index of candidates in TG and DPHG were 25.1 and 24.9, respectively. The mean age at dropout in DPHG was 40.7, similar to the mean age at transplant in TG (39.4). The mean age of diabetes onset was slightly lower in TG (17.4) compared to 20.02 in DPHG. The mean days spent by the candidates on the waitlist in DPHG were significantly higher than those in TG (821 days vs 252 days). Eight of the 45 patients (17.7%) in DPHG had 1 or more organ transplants before listing compared to 1 of 230 patients (0.43%) in TG. Despite low wait times for SPK transplants, increased wait times can account for a dropout from the waitlist due to death or poor health. Centers should exercise caution in wait listing SPK candidates with prior organ transplants.

PRO: Is liver organ allocation with MMaT-3 appropriate prioritization for patients with liver cancer?

PRO: Is liver organ allocation with MMaT-3 appropriate prioritization for patients with liver cancer?

CON: Is liver organ allocation with MMaT-3 appropriate prioritization for patients with liver cancer?

CON: Is liver organ allocation with MMaT-3 appropriate prioritization for patients with liver cancer?

Cost-Effectiveness Analysis of Interventional Liver-Directed Therapies for a Single, Small Hepatocellular Carcinoma in Liver Transplant Candidates

PurposeTo assess the cost effectiveness of 3 main locoregional therapies (LRTs) (transarterial chemoembolization [TACE], transarterial radioembolization [TARE], and percutaneous ablation) as bridging therapy. Materials and MethodsA cost-effectiveness analysis was performed comparing the 3 LRTs for patients with a single hepatocellular carcinoma (HCC) with a diameter of 3 cm or less over a 5-year time horizon from a payer’s perspective. The clinical courses, including transplantation, decompensation resulting in delisting, and the need for a second LRT, were based on data from the United Network for Organ Sharing (2016–2019). Costs and effectiveness were measured in U.S. dollars and quality-adjusted life-years, respectively. Probabilistic and deterministic sensitivity analyses were performed. ResultsA total of 2,594, 1,576, and 903 patients underwent TACE, ablation, and TARE, respectively. Ablation was the dominant strategy, with the lowest expected cost and highest effectiveness. The probabilistic sensitivity analysis demonstrated that ablation was the most cost-effective strategy in 93.9% of simulations. A subgroup analysis was performed for different wait times, with ablation remaining the most cost-effective strategy. The sensitivity analysis showed that ablation was most effective if the risk of waitlist dropout was less than 2.00% and the rate of transplantation was more than 15.1% quarterly. TARE was most effective if the risk of dropout was less than 1.19% and the rate of transplantation was more than 24.0%. TACE was most effective if the risk of dropout was less than 1.01% and the rate of transplantation was more than 45.7%. Ablation remained the most cost-effective modality until its procedural cost was more than $34,843. ConclusionsAblation is the most cost-effective bridging strategy for patients with a single, small (≤3 cm) HCC prior to liver transplantation. The conclusion remained robust in multiple sensitivity analyses.

Predicting waitlist dropout in hepatocellular carcinoma: a narrative review

Predicting waitlist dropout in hepatocellular carcinoma: a narrative review

Racial and Ethnic Disparities in Liver Transplantation in Patients with Hepatocellular Carcinoma

Introduction: Racial and ethnic disparities in outcomes of hepatocellular carcinoma (HCC) have been inadequately studied, especially in the context of liver transplantation (LT). We sought to evaluate disparities among racial/ethnic groups in this patient population to identify ways to mitigate them. Methods: Patient and tumor characteristics were obtained from UNOS STAR files (April 12, 2012 to June 6, 2021). One-way ANOVA and Chi-square tests were conducted for differences among racial/ethnic groups, using non-Hispanic White (NHW) patients as the comparator and Kaplan-Meier plots for survival. Statistical analyses were performed using SAS 9.4. Results: Ninety percent of patients listed for liver transplantation were transplanted or removed from the waitlist after 654 days; ninety-five percent were transplanted or removed after 3 years. Mean graft and patient survival times were the lowest in Hispanics. Hispanics also had the highest physiologic MELD at listing in both recipient and waitlist groups. Among LT recipients, Non-Hispanic Blacks (NHBs) had significantly lower physiologic MELDs at listing and transplantation compared with NHWs. However, NHBs had lower survival at 3 and 5 years after transplant. Hispanics had the highest percentage of poorly differentiated tumors in the explants compared with NHWs and NHBs. Hispanics also had the highest waitlist dropout at 654 days and 3 years. Conclusion: There are significant disparities in HCC outcomes for both the Hispanic and NHB populations compared with NHWs. Whether this is a result of a more advanced cancer stage at listing, differences in HCC tumor biology, or social determinants of health will need further study.

Hepatocellular Carcinoma, Alpha Fetoprotein, and Liver Allocation for Transplantation: Past, Present and Future.

Hepatocellular carcinoma (HCC) is one of the leading indications for liver transplantation and has been the treatment of choice due to the oncologic benefit for patients with advanced chronic liver disease (AdvCLD) and small tumors for the last 25 years. For HCC patients undergoing liver transplantation, alpha fetoprotein (AFP) has increasingly been applied as an independent predictor for overall survival, disease free recurrence, and waitlist drop out. In addition to static AFP, newer studies evaluating the AFP dynamic response to downstaging therapy show enhanced prognostication compared to static AFP alone. While AFP has been utilized to select HCC patients for transplant, despite years of allocation policy changes, the US allocation system continues to take a uniform approach to HCC patients, without discriminating between those with favorable or unfavorable tumor biology. We aim to review the history of liver allocation for HCC in the US, the utility of AFP in liver transplantation, the implications of weaving AFP as a biomarker into policy. Based on this review, we encourage the US transplant community to revisit its HCC organ allocation model, to incorporate more precise oncologic principles for patient selection, and to adopt AFP dynamics to better stratify waitlist dropout risk.

National Experience on Waitlist Outcomes for Down-Staging of Hepatocellular Carcinoma: High Dropout Rate in All-Comers

The United Network for Organ Sharing (UNOS) grants priority listing for liver transplant for patients with hepatocellular carcinoma after successful down-staging to Milan criteria. We evaluated the national experience on down-staging by comparing 2 down-staging groups: tumor burden meeting UNOS down-staging (UNOS-DS) inclusion criteria, and all-comers (AC)-DS with initial tumor burden beyond UNOS-DS criteria vs patients always within Milan criteria. We performed a retrospective analysis of the UNOS database of 23,398 patients listed for liver transplant who had submitted a hepatocellular carcinoma Model for End-Stage Liver Disease exception application from 2010 to 2019, classified as always within Milan (n= 20,579), UNOS-DS (n= 2151), and AC-DS (n= 668). The 2-year cumulative probabilities of dropout were 19% for Milan, 25% for UNOS-DS (P < .001), and 30% for AC-DS (P < .001). In multivariate analysis of the down-staging groups, factors predicting dropout included Model for End-Stage Liver Disease at listing (hazard ratio [HR], 1.06; P < .001) and initial total tumor diameter (HR, 1.04; P= .002). Compared with α-fetoprotein (AFP) level ≤20 ng/mL, AFP levels of 21 to 100, 101 to 1000, and greater than 1000 ng/mL were associated with a higher risk of dropout (HRs, 1.63, 2.06, and 4.58, respectively; P < .001). A subset of all-comers with AFP levels greater than 100 ng/mL had a 2-year probability of dropout of 52% vs 26% for all others beyond Milan criteria (P < .001). All-comers had a significantly higher risk for waitlist dropout compared with the UNOS-DS and Milan groups after initial successful down-staging to Milan criteria. In particular, the subgroup of AC-DS with an AFP level greater than 100 ng/mL had a greater than 50% probability of dropout in the next 2 years. These observations suggest a high likelihood of failure when expanding the indications for down-staging.

Radiofrequency Ablation versus Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma Awaiting Liver Transplant: An Analysis of the Scientific Registry of Transplant Recipients

PurposeTo evaluate differences in waitlist mortality and dropout in liver transplant candidates with hepatocellular carcinoma (HCC) who undergo radiofrequency (RF) ablation versus transarterial chemoembolization (TACE). Material and MethodsFrom 2004 to 2013, 11,824 patients with HCC in the Scientific Registry of Transplant Recipients who underwent RF ablation or TACE were included and followed until December 31, 2019, or 5 years, whichever came first, and were stratified by the Milan criteria. Competing risk and Cox regression analyses to compare waitlist mortality and dropout were performed using adjusted hazard ratios (asHRs, with RF ablation group as reference). Regression models were adjusted for age, race, sex, calculated Model for End-Stage Liver Disease score, tumor size, and number. ResultsThere was no difference in waitlist mortality and dropout for patients outside the Milan criteria (n = 1,226) who underwent TACE (19.2%) or RF ablation (19.0%) (asHR, 0.91; 95% CI, 0.79–1.03). There was also no difference for patients inside the Milan criteria (n = 10,598) in waitlist mortality/dropout (TACE 13.4% vs RF ablation 12.9%) (asHR, 1.29; 95% CI, 0.79–2.09). A subgroup analysis within the Milan criteria demonstrated no difference between TACE and RF ablation treatments in patients with a single tumor of ≤3 cm (asHR, 0.92; 95% CI, 0.77–1.10), with a single tumor of >3 cm (asHR, 1.03; 95% CI, 0.79–1.34), or with >1 tumor (asHR, 0.89; 95% CI, 0.72–1.09). ConclusionsUsing the national registry data, no difference was found in waitlist mortality and dropout for transplant candidates with HCC who received TACE versus RF ablation.

Bridging treatment prior to liver transplantation for hepatocellular carcinoma: radioembolization or transarterial chemoembolization?

BackgroundIn hepatocellular carcinoma (HCC) patients, intraarterial therapies are regularly employed as a bridge to liver transplantation to prevent tumor progression during waiting time. Objective of this study was to compare HCC recurrence after liver transplantation following TACE or radioembolization bridging treatment.MethodsWe retrospectively analyzed prospectively collected data on 131 consecutive HCC patients who underwent liver transplantation between January 2007 and December 2017 at our liver transplant center (radioembolization n = 44, TACE n = 87). Multivariable logistic regression and cox proportional hazard regression models were used to evaluate factors associated with tumor recurrence and post-transplant survival.ResultsBetween groups, patients were comparable with regards to age and gender. In the radioembolization group, Milan criteria for HCC were met significantly less frequently (20.5% vs. 65.5%, p < 0.0001). Patients in the radioembolization group required significantly fewer intraarterial treatments (1 [1–2] vs. 1 [1–7], p = 0.0007). On explant specimen, tumor differentiation, microvascular invasion and tumor necrosis were comparable between the groups. HCC recurrence and overall survival were similar between the groups. Multivariable analysis detected increasing recipient age, male gender, complete tumor necrosis and absence of microvascular invasion being independently associated with decreased odds for HCC recurrence. Increasing model of end-stage liver disease (MELD) score and tumor recurrence were independently associated with increased odds of post-transplant death.ConclusionsIntraarterial bridging treatment leading to tumor necrosis may not only prevent waitlist drop-out but also facilitate long-term successful liver transplantation in HCC patients. Both radioembolization and TACE represent potent treatment strategies.

Living Donor Liver Transplant Center Volume Influences Waiting List Survival Among Children Listed for Liver Transplantation.

Pediatric living donor liver transplantation (LDLT) remains infrequently performed in the United States and localized to a few centers. This study aimed to compare pediatric waiting list and posttransplant outcomes by LDLT center volume. The Scientific Registry of Transplant Recipients/Organ Procurement and Transplantation Network database was retrospectively reviewed for all pediatric (age <18 y) liver transplant candidates listed between January 1, 2009, and December 31, 2019. The average annual number of LDLT, deceased donor partial liver transplant (DDPLT), and overall (ie, LDLT + DDPLT + whole liver transplants) pediatric liver transplants performed by each transplant center during the study period was calculated. Of 88 transplant centers, only 44 (50%) performed at least 1 pediatric LDLT during the study period. LDLT, DDPLT, and overall transplant center volume were all positively correlated. LDLT center volume was protective against waiting list dropout after adjusting for confounding variables (adjusted hazard ratio, 0.92; 95% confidence interval, 0.86-0.97; P = 0.004), whereas DDPLT and overall center volume were not ( P > 0.05); however, DDPLT center volume was significantly protective against both recipient death and graft loss, whereas overall volume was only protective against graft loss and LDLT volume was not protective for either. High-volume pediatric LDLT center can improve waiting list survival, whereas DDPLT and overall volume are associated with posttransplant survival. Expertise in all types of pediatric liver transplant options is important to optimize outcomes.

National experience with living donor liver transplantation for hepatocellular carcinoma.

Living donor liver transplantation (LDLT) is an attractive option to decrease waitlist dropout, particularly for patients with hepatocellular carcinoma (HCC) who face lengthening waiting times. Using the United Network for Organ Sharing (UNOS) national database, trends in LDLT utilization for patients with HCC were evaluated, and post-LT outcomes for LDLT versus deceased donor liver transplantation (DDLT) were compared. From 1998 to 2018, LT was performed in 20,161 patients with HCC including 726 (3.6%) who received LDLT. The highest LDLT utilization was prior to the 2002 HCC Model for End-Stage Liver Disease (MELD) exception policy (17.5%) and dropped thereafter (3.1%) with a slight increase following the 6-month wait policy in 2015 (3.8%). LDLT was more common in patients from long-wait UNOS regions with blood type O, in those with larger total tumor diameter (2.3 vs. 2.1cm, p=0.02), and higher alpha-fetoprotein at LT (11.5 vs. 9.0ng/ml, p=0.04). The 5-year post-LT survival (LDLT 77% vs. DDLT 75%), graft survival (72% vs. 72%), and HCC recurrence (11% vs. 13%) were similar between groups (all p>0.20). In conclusion, LDLT utilization for HCC has remained low since 2002 with only a slight increase after the 6-month wait policy introduction in 2015. Given the excellent post-LT survival, LDLT appears to be an underutilized but valuable option for patients with HCC, especially those at high risk for waitlist dropout.

Early Impact of MMaT-3 Policy on Liver Transplant Waitlist Outcomes for Hepatocellular Carcinoma.

Background.To reduce the disparity in access to liver transplant (LT), United Network for Organ Sharing implemented an exception policy in May 2019, which capped hepatocellular carcinoma (HCC) exception score to the median Model for End-Stage Liver Disease (MELD) at transplant within the donor service area minus 3 points (MMaT-3) after the 6-mo wait period. We aimed to evaluate how this policy affected HCC waitlist outcomes.Methods.Using United Network for Organ Sharing data, we analyzed waitlist outcomes in HCC patients at the time they received exception points from in the pre-MMaT era (August 15, 2017, to November 15, 2018) and MMaT era (June 1, 2019, to August 30, 2020). Comparisons were made within the HCC group and HCC versus non-HCC (at time of listing) groups in the pre-MMaT and MMaT eras and regions were grouped as low, medium, and high MELD based on MMaT.Results.HCC group: LT probability within HCC patients decreased by 20% (subhazard ratio [sHR], 0.78; 95% confidence interval [CI], 0.74-0.85) between the eras and decreased by 41% in low MELD regions (sHR, 0.59; 95% CI, 0.52-0.66). Waitlist dropout was unchanged. Matched HCC versus non-HCC groups: HCC patients had 80% higher LT probability (sHR, 1.84; 95% CI, 1.71-1.99) than non-HCC patients in the pre-MMaT era; which decreased to a 14% higher LT probability in MMaT era. In low and medium regions, HCC patients had over twofold higher LT probability in the pre-MMaT era, which decreased to a ~20% higher probability (sHR, 1.14; 95% CI, 1.06-1.23) in the MMaT era. After implementation of the acuity circle policy, HCC patients had lower LT probability (sHR, 0.84; 95% CI, 0.74-0.94) than non-HCC patients.Conclusions.The geographic disparity between HCC and non-HCC patients has improved with the MMaT-3 policy. Despite lower LT probability for HCC patients, waitlist dropout was not adversely impacted.

Machine learning to predict waitlist dropout among liver transplant candidates with hepatocellular carcinoma.

BackgroundAccurate prediction of outcome among liver transplant candidates with hepatocellular carcinoma (HCC) remains challenging. We developed a prediction model for waitlist dropout among liver transplant candidates with HCC.MethodsThe study included 18,920 adult liver transplant candidates in the United States listed with a diagnosis of HCC, with data provided by the Organ Procurement and Transplantation Network. The primary outcomes were 3‐, 6‐, and 12‐month waitlist dropout, defined as removal from the liver transplant waitlist due to death or clinical deterioration.ResultsUsing 1,181 unique variables, the random forest model and Spearman's correlation analyses converged on 12 predictive features involving 5 variables, including AFP (maximum and average), largest tumor size (minimum, average, and most recent), bilirubin (minimum and average), INR (minimum and average), and ascites (maximum, average, and most recent). The final Cox proportional hazards model had a concordance statistic of 0.74 in the validation set. An online calculator was created for clinical use and can be found at: http://hcclivercalc.cloudmedxhealth.com/.ConclusionIn summary, a simple, interpretable 5‐variable model predicted 3‐, 6‐, and 12‐month waitlist dropout among patients with HCC. This prediction can be used to appropriately prioritize patients with HCC and their imminent need for transplant.