Impact of major hepatocellular carcinoma policy changes on liver transplantation for hepatocellular carcinoma in the United States

Predicting long-term survival among patients with HCC

BACKGROUND

Prognosticating survival among patients with HCC and cirrhosis must account for both the tumor burden/stage, as well as the severity of the underlying liver disease. Although there are many staging systems used to guide therapy, they have not been widely adopted to predict patient-level survival after the diagnosis of HCC. We sought to develop a score to predict long-term survival among patients with early- to intermediate-stage HCC using purely objective criteria.

METHODS

Retrospective cohort study among patients with HCC confined to the liver, without major medical comorbidities within the Veterans Health Administration from 2014 to 2023. Tumor data were manually abstracted and combined with clinical and laboratory data to predict 5-year survival from HCC diagnosis using accelerated failure time models. The data were randomly split using a 75:25 ratio for training and validation. Model discrimination and calibration were assessed and compared to other HCC staging systems.

RESULTS

The cohort included 1325 patients with confirmed HCC. A risk score using baseline clinical, laboratory, and HCC-related survival had excellent discrimination (integrated AUC: 0.71 in the validation set) and calibration (based on calibration plots and Brier scores). Models had superior performance to the BCLC and ALBI scores and similar performance to the combined BCLC-ALBI score.

CONCLUSIONS

We developed a risk score using purely objective data to accurately predict long-term survival for patients with HCC. This score, if validated, can be used to prognosticate survival for patients with HCC, and, in the setting of liver transplantation, can be incorporated to consider the net survival benefit of liver transplantation versus other curative options.

Waitlist Outcomes for Exception and Non-exception Liver Transplant Candidates in the United States Following Implementation of the Median MELD at Transplant (MMaT)/250-mile Policy

BACKGROUND

Since February 2020, exception points have been allocated equivalent to the median model for end-stage liver disease at transplant within 250 nautical miles of the transplant center (MMaT/250). We compared transplant rate and waitlist mortality for hepatocellular carcinoma (HCC) exception, non-HCC exception, and non-exception candidates to determine whether MMaT/250 advantages (or disadvantages) exception candidates.

METHODS

Using Scientific Registry of Transplant Recipients data, we identified 23 686 adult, first-time, active, deceased donor liver transplant (DDLT) candidates between February 4, 2020, and February 3, 2022. We compared DDLT rates using Cox regression, and waitlist mortality/dropout using competing risks regression in non-exception versus HCC versus non-HCC candidates.

RESULTS

Within 24 mo of study entry, 58.4% of non-exception candidates received DDLT, compared with 57.8% for HCC candidates and 70.5% for non-HCC candidates. After adjustment, HCC candidates had 27% lower DDLT rate (adjusted hazard ratio =  0.68 0.73 0.77 ) compared with non-exception candidates. However, waitlist mortality for HCC was comparable to non-exception candidates (adjusted subhazard ratio [asHR] =  0.93 1.03 1.15 ). Non-HCC candidates with pulmonary complications of cirrhosis or cholangiocarcinoma had substantially higher risk of waitlist mortality compared with non-exception candidates (asHR =  1.27 1.70 2.29 for pulmonary complications of cirrhosis, 1.35 2.04 3.07 for cholangiocarcinoma). The same was not true of non-HCC candidates with exceptions for other reasons (asHR =  0.54 0.88 1.44 ).

CONCLUSIONS

Under MMaT/250, HCC, and non-exception candidates have comparable risks of dying before receiving liver transplant, despite lower transplant rates for HCC. However, non-HCC candidates with pulmonary complications of cirrhosis or cholangiocarcinoma have substantially higher risk of dying before receiving liver transplant; these candidates may merit increased allocation priority.

The Future Frontier of Liver Transplantation Exploring Young Donor Allocation Strategies for HCC Recipients

Background

The role of donor age in liver transplantation (LT) outcomes for hepatocellular carcinoma (HCC) is controversial. Given the significant risk of HCC recurrence post-LT, optimizing donor/recipient matching is crucial. This study reassesses the impact of young donors on LT outcomes in patients with HCC.

Methods

A retrospective review of 11 704 LT cases from the United Network for Organ Sharing database (2012-2021) was conducted. The study focused on the effect of donor age on recurrence-free survival, using hazard associated with LT for HCC (HALT-HCC) and Metroticket 2.0 scores to evaluate post-LT survival in patients with HCC.

Results

Of 4706 cases with young donors, 11.0% had HCC recurrence or death within 2 y, and 18.3% within 5 y. These outcomes were comparable with those of non-young donors. A significant correlation between donor age and post-LT recurrence or mortality (P = 0.04) was observed, which became statistically insignificant after tumor-related adjustments (P = 0.32). The Kaplan-Meier curve showed that recipients with lower HALT-HCC scores (<9) and Metroticket 2.0 scores (<2.2) significantly benefited from young donors, unlike those exceeding these score thresholds. Cox regression analysis showed that donor age significantly influenced outcomes in recipients below certain score thresholds but was less impactful for higher scores.

Conclusions

Young donors are particularly beneficial for LT recipients with less aggressive HCC, as indicated by their HALT-HCC and Metroticket 2.0 scores. These findings suggest strategically allocating young donors to recipients with less aggressive tumor profiles, which could foster more efficient use of the scarce donor supply and potentially enhance post-LT outcomes.

The impact of surging transplantation of alcohol-associated liver disease on transplantation for HCC and other indications

BACKGROUND

Liver transplantation (LT) for alcohol-associated liver disease (ALD) is increasing and may impact LT outcomes for patients listed for HCC and other indications.

METHODS

Using US adults listed for primary LT (grouped as ALD, HCC, and other) from October 8, 2015, to December 31, 2021, we examined the impact of center-level ALD LT volume (ATxV) on waitlist outcomes in 2 eras: Era 1 (6-month wait for HCC) and Era 2 (MMaT-3). The tertile distribution of ATxV (low to high) was derived from the listed candidates as Tertile 1 (T1): <28.4%, Tertile 2 (T2): 28.4%-37.6%, and Tertile 3 (T3): >37.6% ALD LTs per year. Cumulative incidence of waitlist death and LT within 18 months from listing by LT indication were compared using the Gray test, stratified on eras and ATxV tertiles. Multivariable competing risk regression estimated the adjusted subhazard ratios (sHRs) for the risk of waitlist mortality and LT with interaction effects of ATxV by LT indication (interaction p).

RESULTS

Of 56,596 candidates listed, the cumulative waitlist mortality for those with HCC and other was higher and their LT probability was lower in high (T3) ATxV centers, compared to low (T1) ATxV centers in Era 2. However, compared to ALD (sHR: 0.92 [0.66-1.26]), the adjusted waitlist mortality for HCC (sHR: 1.15 [0.96-1.38], interaction p = 0.22) and other (sHR: 1.13 [0.87-1.46], interaction p = 0.16) were no different suggesting no differential impact of ATxV on the waitlist mortality. The adjusted LT probability for HCC (sHR: 0.89 [0.72-1.11], interaction p = 0.08) did not differ by AtxV while it was lower for other (sHR: 0.82 [0.67-1.01], interaction p = 0.02) compared to ALD (sHR: 1.04 [0.80-1.34]) suggesting a differential impact of ATxV on LT probability.

CONCLUSIONS

The high volume of LT for ALD does not impact waitlist mortality for HCC and others but affects LT probability for other in the MMAT-3 era warranting continued monitoring.

Exception Policy Change Increased the Simultaneous Kidney-Liver Transplant Probability of Polycystic Disease in the Centers With High Median MELD at Transplantation

BACKGROUND

In 2019, Organ Procurement and Transplantation Network/United Network for Organ Sharing changed the exception policy for liver allocation to the median model for end-stage liver disease at transplantation (MMaT). This study evaluated the effects of this change on-waitlist outcomes of simultaneous liver-kidney transplantation (SLKT) for patients with polycystic liver-kidney disease (PLKD).

METHODS

Using the Organ Procurement and Transplantation Network/United Network for Organ Sharing registry, 317 patients with PLKD listed for SLKT between January 2016 and December 2021 were evaluated. Waitlist outcomes were compared between prepolicy (Era 1) and postpolicy (Era 2) eras.

RESULTS

One-year transplant probability was significantly higher in Era 2 than in Era 1 (55.7% versus 37.9%; P  = 0.001), and the positive effect on transplant probability of Era 2 was significant after risk adjustment (adjusted hazard ratio, 1.76; 95% confidence interval, 1.22-2.54; P  = 0.002 [ref. Era 1]), whereas waitlist mortality was comparable. Transplant centers were separated into the high and low MMaT groups with a score of 29 (median MMaT) and transplant probability in each group between eras was compared. In the high MMaT transplant centers, the 1-y transplant probability was significantly higher in Era 2 (27.5% versus 52.4%; P  = 0.003). The positive effect remained significant in the high MMaT center group (adjusted hazard ratio, 2.79; 95% confidence interval, 1.43-5.46; P  = 0.003 [ref. Era 1]) but not in the low MMaT center group. Although there was a difference between center groups in Era 1 ( P  = 0.006), it became comparable in Era 2 ( P  = 0.54).

CONCLUSIONS

The new policy increased 1-y SLKT probability in patients with PKLD and successfully reduced the disparities based on center location.

Transplant center variability in utilizing nonstandard donors and its impact on the transplantation of patients with lower MELD scores

There is a subset of patients with lower MELD scores who are at substantial risk of waitlist mortality. In order to transplant such patients, transplant centers must utilize "nonstandard" donors (eg, living donors, donation after circulatory death), which are traditionally offered to those patients who are not at the top of the waitlist. We used Organ Procurement and Transplantation data to evaluate center-level and region-level variability in the utilization of nonstandard donors and its impact on MELD at transplant among adult liver-alone non-status 1 patients transplanted from April 1, 2020, to September 30, 2022. The center-level variability in the utilization of nonstandard donors was 4-fold greater than the center-level variability in waitlisting practices (waitlistings with a MELD score of <20). While there was a moderate correlation between center-level waitlisting and transplantation of patients with a MELD score of <20 ( p = 0.58), there was a strong correlation between center-level utilization of nonstandard donors and center-level transplantation of patients with a MELD score of <20 ( p = 0.75). This strong correlation between center-level utilization of "nonstandard" donors and center-level transplantation of patients with a MELD score of <20 was limited to regions 2, 4, 5, 9, and 11. Transplant centers that utilize more nonstandard donors are more likely to successfully transplant patients at lower MELD scores. Public reporting of these data could benefit patients, caregivers, and referring providers, and be used to help maximize organ utilization.

Statins in Chronic Liver Disease: Review of the Literature and Future Role

Chronic liver disease (CLD) is a major contributor to global mortality, morbidity, and healthcare burden. Progress in pharmacotherapeutic for CLD management is lagging given its impact on the global population. While statins are indicated for the management of dyslipidemia and cardiovascular disease, their role in CLD prevention and treatment is emerging. Beyond their lipid-lowering effects, their liver-related mechanisms of action are multifactorial and include anti-inflammatory, antiproliferative, and immune-protective effects. In this review, we highlight what is known about the clinical benefits of statins in viral and nonviral etiologies of CLD and hepatocellular carcinoma (HCC), and explore key mechanisms and pathways targeted by statins. While their benefits may span the spectrum of CLD and potentially HCC treatment, their role in CLD chemoprevention is likely to have the largest impact. As emerging data suggest that genetic variants may impact their benefits, the role of statins in precision hepatology will need to be further explored.

Implementation of a National Liver Review Board for exception requests in the United States: A 2-year monitoring report

The exception point system for liver allocation in the United States allows for additional waitlist priority for candidates where the Model for End-Stage Liver Disease or Pediatric End-stage Liver Disease does not effectively represent their urgency or need for a transplant. In May 2019, the review process for liver exception cases transitioned from 11 Regional Review Boards (RRBs) to 1 National Liver Review Board (NLRB), intended to increase consistency nationwide, improve efficiency, and balance transplant access for candidates with and without exception scores. This report provides a review of liver exception request and review practices, waitlist outcomes, and transplant activity in the first 2 years after implementation of the NLRB and acuity circle-based distribution in the United States. We compared initial and extension exception request forms submitted from May 13, 2017 to May 13, 2019 (prepolicy or RRB era) to the period from February 4, 2020 to February 3, 2022 (postpolicy or NLRB era). During this time, the NLRB reviewed 10,083 initial exception requests and 12,686 extension requests. Notable postpolicy highlights include (1) an increase in the proportion of initial and extension requests that were automatically approved instead of manually reviewed; (2) a decrease in the overall approval rates of initial exception requests (87.8% for adult HCC, 64.3% for adult other diagnoses, and 71.5% for pediatric); and (3) reduction in the time from exception request submission to adjudication to a median of 3.73 days. The proportions of waitlist registration and deceased donor liver transplants for patients with exception scores decreased, and waitlist outcomes between patients with and without exception scores are now comparable. Implementation of the NLRB improved efficiency, reduced case workloads, and standardized criteria for exception cases, with similar waitlist outcomes between patients with and without exception scores and improved equity in terms of access to liver transplants.

Living Donor Liver Transplantation for Hepatocellular Carcinoma Within and Outside Traditional Selection Criteria: A Multicentric North American Experience

OBJECTIVE

To evaluate long-term oncologic outcomes of patients post-living donor liver transplantation (LDLT) within and outside standard transplantation selection criteria and the added value of the incorporation of the New York-California (NYCA) score.

BACKGROUND

LDLT offers an opportunity to decrease the liver transplantation waitlist, reduce waitlist mortality, and expand selection criteria for patients with hepatocellular carcinoma (HCC).

METHODS

Primary adult LDLT recipients between October 1999 and August 2019 were identified from a multicenter cohort of 12 North American centers. Posttransplantation and recurrence-free survival were evaluated using the Kaplan-Meier method.

RESULTS

Three hundred sixty LDLTs were identified. Patients within Milan criteria (MC) at transplantation had a 1, 5, and 10-year posttransplantation survival of 90.9%, 78.5%, and 64.1% versus outside MC 90.4%, 68.6%, and 57.7% ( P = 0.20), respectively. For patients within the University of California San Francisco (UCSF) criteria, respective posttransplantation survival was 90.6%, 77.8%, and 65.0%, versus outside UCSF 92.1%, 63.8%, and 45.8% ( P = 0.08). Fifty-three (83%) patients classified as outside MC at transplantation would have been classified as either low or acceptable risk with the NYCA score. These patients had a 5-year overall survival of 72.2%. Similarly, 28(80%) patients classified as outside UCSF at transplantation would have been classified as a low or acceptable risk with a 5-year overall survival of 65.3%.

CONCLUSIONS

Long-term survival is excellent for patients with HCC undergoing LDLT within and outside selection criteria, exceeding the minimum recommended 5-year rate of 60% proposed by consensus guidelines. The NYCA categorization offers insight into identifying a substantial proportion of patients with HCC outside the MC and the UCSF criteria who still achieve similar post-LDLT outcomes as patients within the criteria.

Impact of Median MELD at Transplant Minus 3 National Policy on Quality of Transplanted Livers for Patients With and Without Hepatocellular Carcinoma

BACKGROUND

Patients with hepatocellular carcinoma (HCC) have been overprioritized in the deceased donor liver allocation system. The United Network for Organ Sharing adopted a policy in May 2019 that limited HCC exception points to the median Model for End-Stage Liver Disease at transplant in the listing region minus 3. We hypothesized this policy change would increase the likelihood to transplant marginal quality livers into HCC patients.

METHODS

This was a retrospective cohort study of a national transplant registry, including adult deceased donor liver transplant recipients with and without HCC from May 18, 2017, to May 18, 2019 (prepolicy) to May 19, 2019, to March 1, 2021 (postpolicy). Transplanted livers were considered of marginal quality if they met ≥1 of the following: (1) donation after circulatory death, (2) donor age ≥70, (3) macrosteatosis ≥30% and (4) donor risk index ≥95th percentile. We compared characteristics across policy periods and by HCC status.

RESULTS

A total of 23 164 patients were included (11 339 prepolicy and 11 825 postpolicy), 22.7% of whom received HCC exception points (prepolicy versus postpolicy: 26.1% versus 19.4%; P = 0.03). The percentage of transplanted donor livers meeting marginal quality criteria decreased for non-HCC (17.3% versus 16.0%; P < 0.001) but increased for HCC (17.7% versus 19.4%; P < 0.001) prepolicy versus postpolicy. After adjusting for recipient characteristics, HCC recipients had 28% higher odds of being transplanted with marginal quality liver independent of policy period (odds ratio: 1.28; confidence interval, 1.09-1.50; P < 0.01).

CONCLUSIONS

The median Model for End-Stage Liver Disease at transplant in the listing region minus 3 policy limited exception points and decreased the quality of livers received by HCC patients.

Optimizing liver transplant prioritization for hepatocellular carcinoma through risk stratification

PURPOSE OF REVIEW

In the United States, candidates with hepatocellular carcinoma (HCC) meeting standardized qualifying criteria receive similar priority on the liver transplant waiting list through Model for End-Stage Liver Disease exception points, without consideration of the dropout risk or relative expected benefit from liver transplantation. A more nuanced allocation scheme for HCC is needed to better represent the individual urgency for liver transplant and optimize organ utility. In this review, we discuss the development of HCC risk prediction models for practical use in liver allocation.

RECENT FINDINGS

HCC is a heterogenous disease that requires improved risk stratification for patients who fall within current transplant eligibility criteria. Several models have been proposed, though none have been adopted in clinical practice or liver allocation to date, due to various limitations.

SUMMARY

Improved HCC risk stratification for liver transplant candidates is needed to more accurately represent their urgency for transplant, with continued attention to the potential impact on post-liver transplant outcomes. Plans to implement a continuous distribution model for liver allocation in the United States may provide an opportunity to re-consider a more equitable allocation scheme for patients with HCC.

Updates and Expert Opinions on Liver Transplantation for Gastrointestinal Malignancies

Transplant oncology is a relatively new field in which transplantation is used to treat patients who would otherwise be unresectable. New anticancer treatment paradigms using tumor and transplant immunology and cancer immunogenomics are emerging. In turn, liver transplantation (LT) has become a potential therapy for certain patients with colorectal cancer (CRC) with liver metastasis, hepatocellular (HCC), cholangiocarcinoma (CCA), and metastatic neuroendocrine tumor (NET) of the liver. Although there are established criteria for LT in HCC, evidence regarding LT as a treatment modality for certain gastrointestinal malignancies is still debated. The aim of this review is to highlight updates in the role of LT for certain malignancies, including HCC, metastatic CRC, hilar CCA, and neuroendocrine tumor (NET), as well as contextualize LT use and discuss controversies in transplant oncology.

Would a 6-Month Wait Time for Patients With Hepatocellular Carcinoma Improve Organ Allocation in Centers With Active Living Related Liver Transplant Activity?

OBJECTIVES

The Model for End-Stage Liver Disease score is used to prioritize patients awaiting liver transplant. Since hepatocellular carcinoma does not affect the score, patients with hepatocellular carcinoma are given exception points to promote fairness. In the United States,this practice has resulted in overcorrection; hence, a 6-month delay to grant exceptions was implemented. A similar flaw may exist in Saudi Arabia.

MATERIALS AND METHODS

We retrospectively reviewed data for 214 adults listed for liver transplant from January 2016 to July 2020 at King Abdulaziz Medical City, Riyadh. Data included diagnoses, Model for End-Stage Liver Disease scores, wait times, and outcomes. Comparative analyses were performed to contrast patients with hepatocellular carcinoma versus patients without hepatocellular carcinoma.

RESULTS

Mean age was 55.2 ± 11.6 years, and 61% were male patients. Outcomes were that the patient received a transplant(77%; n = 165/214), dropped out (18%; n = 38/214), or remained on the wait (5%; n = 11/214). Of the hepatocellular carcinoma group, 84% (n = 56/68) received transplant versus 74% (n = 108/146) in the control group (P = .11). There was no significant difference in dropout rates (P = .33). Patients with hepatocellular carcinoma constituted 32% (n = 68/214) ofthe waitlist, yetthey received 40% of deceased organ offers (P = .015). Most patients in the hepatocellular carcinoma group received pretransplant bridging therapy for a median of 166 days (101-329.5 days). Median time from listing to transplant was shorter for the control group, 57 days versus 148 days (P < .001). Long-term outcomes were comparable between both groups.

CONCLUSIONS

This study suggests that implementation of the 6-month wait time for patients with hepatocellular carcinoma before granting exception points may not be necessary for active living related liver transplant programs. Nevertheless, this remains a sound strategy to follow.

Introducing Machine Perfusion into Routine Clinical Practice for Liver Transplantation in the United States: The Moment Has Finally Come

While adoption of machine perfusion technologies into clinical practice in the United States has been much slower than in Europe, recent changes in the transplant landscape as well as device availability following FDA approval have paved the way for rapid growth. Machine perfusion may provide one mechanism to maximize the utilization of potential donor liver grafts. Indeed, multiple studies have shown increased organ utilization with the implementation of technologies such as ex-situ normothermic machine perfusion (NMP), ex-situ hypothermic machine perfusion (HMP) and in-situ normothermic regional perfusion (NRP). The current review describes the history and development of machine perfusion utilization in the Unites States along with future directions. It also describes the differences in landscape between Europe and the United States and how this has shaped clinical application of these technologies.