Predictors of low risk for dropout from the liver transplant waiting list for hepatocellular carcinoma in long wait time regions: Implications for organ allocation

Evaluation of a delayed liver transplantation strategy for patients with HCC receiving bridging therapy: the DELTA-HCC study

BACKGROUND & AIMS

To maximize utility and prevent premature liver transplantation (LT), a delayed LT strategy (DS) was adopted in France in 2015 in patients listed for any single HCC treated with resection or thermal ablation during the waiting phase. The DS involves postponing LT until recurrence. The purpose of this study was to evaluate the DS to make sure that it did not hamper pre- and post-LT outcomes.

METHODS

Patients listed for HCC in France between 2015 and 2018 were studied. After data extraction from the national LT database, 2,025 patients were identified and classified according to six groups: single tumor entering DS, single tumor not entering DS, multiple tumors, no curative treatment, untreatable HCC or T1 tumors. Kaplan-Meier estimates of the 18-month risk of dropout for death, too sick to be transplanted or tumor progression before LT, 5-year post-LT HCC recurrence and post-LT survival rates were compared.

RESULTS

Median waiting-time in the DS group was 910 days. Pre-LT dropout probability was significantly lower in the DS group compared to other groups (13% vs. 19%, p = 0.0043) and significantly higher in the T1 group (25.4%, p = 0.05). Post-LT HCC recurrence rate in the multiple nodules group was significantly higher (19.6%, p = 0.019), while 5-year post-LT survival did not differ among groups and was 74% in the DS group (p = 0.22).

CONCLUSION

The DELTA-HCC study shows that DS does not negatively impact either pre- nor post-LT patient outcomes, and has the potential to allow for redistribution of organs to patients in more urgent need of LT. It can reasonably be proposed and pursued. The unexpectedly high risk of dropout in T1 patients seems related to the MELD-based offering rules underserving this subgroup.

IMPACTS AND IMPLICATIONS

To maximize utility and prevent premature liver transplantation (LT), a delayed LT strategy was adopted in France in 2015. It involves postponing LT until recurrence in patients listed for any single HCC curatively treated by surgical resection or thermal ablation. The DELTA-HCC study was conducted to evaluate this nationwide strategy. It shows in a European LT program that delayed strategy does not negatively impact pre- nor post-LT patient outcomes and is relevant to up to 20% of LT candidates; thus, it could potentially enable the redistribution of organs to patients in more urgent need of LT. Such a delayed strategy can reasonably be pursued and extended to other LT programs. Of note, an unexpectedly high risk of dropout in T1 patients, seemingly related to MELD-based offering rules which underserve these patients, calls for further scrutinization and revision of allocation rules in this subgroup.

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.

The impact of waiting time and delayed treatment on the outcomes of patients with hepatocellular carcinoma: A systematic review and meta-analysis

Hepatocellular carcinoma (HCC) is the sixth most diagnosed cancer worldwide. Healthcare resource constraints may predispose treatment delays. We aim to review existing literature on whether delayed treatment results in worse outcomes in HCC. PubMed, Embase, The Cochrane Library, and Scopus were systematically searched from inception till December 2022. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Secondary outcomes included post-treatment mortality, readmission rates, and complications. Fourteen studies with a total of 135,389 patients (delayed n = 25,516, no delay n = 109,873) were included. Age, incidence of male patients, Child-Pugh B cirrhosis, and Barcelona Clinic Liver Cancer Stage 0/A HCC were comparable between delayed and no delay groups. Tumor size was significantly smaller in delayed versus no delay group (mean difference, -0.70 cm; 95% confidence interval [CI]: -1.14, 0.26; p = 0.002). More patients received radiofrequency ablation in delayed versus no delay group (OR, 1.22; 95% CI: 1.16, 1.27; p < 0.0001). OS was comparable between delayed and no delay in HCC treatment (hazard ratio [HR], 1.13; 95% CI: 0.99, 1.29; p = 0.07). Comparable DFS between delayed and no delay groups (HR, 0.99; 95% CI: 0.75, 1.30; p = 0.95) was observed. Subgroup analysis of studies that defined treatment delay as > 90 days showed comparable OS in the delayed group (HR, 1.04; 95% CI: 0.93, 1.16; p = 0.51). OS and DFS for delayed treatment were non-inferior compared to no delay, but might be due to better tumor biology/smaller tumor size in the delayed group.

Liver Transplantation for Hepatocellular Carcinoma: A Narrative Review and A Glimpse into The Future

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.

Optimal Liver Transplantation Criteria for Hepatocellular Carcinoma

Liver transplantation continues to be the optimal treatment for hepatocellular carcinoma (HCC). Given the limited organ supply, patient selection for liver transplant must carefully balance tumor progression with risk of recurrence posttransplant. There are several pretransplant selection criteria that incorporate biomarkers as well as imaging modality to risk-stratify patients as we continue to look for the optimal transplant cutoff for patients with HCC, which should be transplant-center specific, and account for organ availability and dynamic response to locoregional therapy.

Benefit and harm of waiting time in liver transplantation for HCC

Liver transplantation is the most successful treatment for limited-stage HCC. The waiting time for liver transplantation (LT) can be a critical factor affecting the oncological prognosis and outcome of patients with HCC. Efficient strategies to optimize waiting time are essential to maximize the benefits of LT and to reduce the harm of delay in transplantation. The ever-increasing demand for donor livers emphasizes the need to improve the organization of the waiting list for transplantation and to optimize organ availability for patients with and without HCC. Current progress in innovations to expand the donor pool includes the implementation of living donor LT and the use of grafts from extended donors. By expanding selection criteria, an increased number of patients are eligible for transplantation, which necessitates criteria to prevent futile transplantations. Thus, the selection criteria for LT have evolved to include not only tumor characteristics but biomarkers as well. Enhancing our understanding of HCC tumor biology through the analysis of subtypes and molecular genetics holds significant promise in advancing the personalized approach for patients. In this review, the effect of waiting time duration on outcome in patients with HCC enlisted for LT is discussed.

Optimal treatment for small HCC (<3 cm): Resection, liver transplantation, or locoregional therapy?

Hepatocellular carcinoma (HCC) remains the most common form of liver cancer, accounting for 90% of all primary liver cancers. Up to 30% of HCC cases could be small (2-3 cm in diameter) at the time of diagnosis with advances in imaging techniques and surveillance programmes. Treating patients with early-stage HCC can be complex and often requires interdisciplinary care, owing to the wide and increasing variety of treatment options, which include liver resection, liver transplantation, and various locoregional therapies offered by interventional radiology and radiation oncology. Decisions regarding the optimal management strategy for a patient involve many considerations, including patient- and tumour-specific characteristics, as well as socioeconomic factors. In this review, we aim to comprehensively summarise the commonly used therapies for single, small HCC (<3 cm), with a focus on the impact of tumour size (<2 cm vs. 2-3 cm), as well as a brief discussion on the cost-effectiveness of the different treatment options.

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.

Liver Transplant in Patients with Hepatocarcinoma: Imaging Guidelines and Future Perspectives Using Artificial Intelligence

Hepatocellular carcinoma is the most common primary malignant hepatic tumor and occurs most often in the setting of chronic liver disease. Liver transplantation is a curative treatment option and is an ideal solution because it solves the chronic underlying liver disorder while removing the malignant lesion. However, due to organ shortages, this treatment can only be applied to carefully selected patients according to clinical guidelines. Artificial intelligence is an emerging technology with multiple applications in medicine with a predilection for domains that work with medical imaging, like radiology. With the help of these technologies, laborious tasks can be automated, and new lesion imaging criteria can be developed based on pixel-level analysis. Our objectives are to review the developing AI applications that could be implemented to better stratify liver transplant candidates. The papers analysed applied AI for liver segmentation, evaluation of steatosis, sarcopenia assessment, lesion detection, segmentation, and characterization. A liver transplant is an optimal treatment for patients with hepatocellular carcinoma in the setting of chronic liver disease. Furthermore, AI could provide solutions for improving the management of liver transplant candidates to improve survival.

Interval dynamics of transplantability for hepatocellular carcinoma after primary curative resection: risk factors for nontransplantable recurrence

BACKGROUND

To investigate the changes in transplantability between primary and recurrent Hepatocellular carcinoma (HCC) after hepatic resection (HR) and the risk factors for nontransplantable recurrence (NTR).

METHODS

Consecutive 3122 patients who received HR for primary HCC between 2001 and 2019 were analyzed for changes in transplantability. Predictors of survival and NTR were evaluated using a competing risk analysis.

RESULTS

After a median follow-up of 78.3 months, the 5-year overall survival rate was 82.6%. Also, 58.2% of them developed recurrence after a median of 45.6 months. Recurrence occurred in 1205 and 611 patients with primary transplantable and nontransplantable HCC, respectively, of whom 26.1% and 63.2%, respectively, had NTR. Tumor diameter >3 cm [subdistribution hazard ratios (95% CI), 2.00 (1.62-2.48)], major resection [1.20 (1.00-1.43)], pathological grade >2 [1.28 (1.07-1.52)], microvascular invasion [1.74 (1.45-2.08)], and early recurrence (<1 year) [9.22 (7.83-10.87)] were associated with NTR. The overall transplantable pool increased from 72.3% to 77.5%.

CONCLUSION

Microvascular invasion and early recurrence were risk factors for NTR. Nonetheless, the transplantable pool increased after HR, 41.8% of the patients had no recurrence and may not require liver transplantation. If the patient's liver function is acceptable, HR should be considered the treatment of choice for HCC.

Magnetic Resonance Imaging Predictors of Hepatocellular Carcinoma Progression and Dropout in Patients in Liver Transplantation Waiting List

With the rising incidence of hepatocellular carcinoma (HCC), more patients are now eligible for liver transplantation. Consequently, HCC progression and dropout from the waiting list are also anticipated to rise. We developed a predictive model based on radiographic features and alpha-fetoprotein to identify high-risk patients.

METHODS

This is a case-cohort retrospective study of 76 patients with HCC who were listed for liver transplantation with subsequent liver transplantation or delisting due to HCC progression. We analyzed imaging-based predictive variables including tumor margin (well- versus ill-defined), capsule bulging lesions, volumetric analysis and distance to portal vein, tumor numbers, and tumor diameter. Volumetric analysis of the index lesions was used to quantify index tumor total volume and volumetric enhancement, whereas logistic regression and receiver operating characteristic curve (ROC) analyses were used to predict the main outcome of disease progression.

RESULTS

In univariate analyses, the following baseline variables were significantly associated with disease progression: size and number of lesions, sum of lesion diameters, lesions bulging the capsule, and total and venous-enhancing (viable) tumor volumes. Based on multivariable analyses, a risk model including lesion numbers and diameter, capsule bulging, tumor margin (infiltrative versus well-defined), and alpha-fetoprotein was developed to predict HCC progression and dropout. The model has an area under the ROC of 82%, which was significantly higher than Milan criteria that has an area under the ROC of 67%.

CONCLUSIONS

Our model has a high predictive test for patient dropout due to HCC progression. This model can identify high-risk patients who may benefit from more aggressive HCC treatment early after diagnosis to prevent dropout due to such disease progression.

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 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. 2.1 cm, p = 0.02), and higher alpha-fetoprotein at LT (11.5 vs. 9.0 ng/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.

The Impact of Median Model for End-Stage Liver Disease at Transplant Minus 3 National Policy on Waitlist Outcomes in Patients With and Without Hepatocellular Carcinoma

As a result of ongoing regional disparities, the United Network for Organ Sharing (UNOS) implemented policy in May 2019 limiting exception points for waitlisted patients with hepatocellular carcinoma (HCC) to median Model for End-Stage Liver Disease at transplant in the area surrounding a transplant center minus 3 points (MMAT-3). The impact of this policy change remains unknown. We included adult patients with HCC (n = 4567) and without HCC (n = 19,773) in the UNOS database added to the waiting list before this policy change (May 7, 2017-May 18, 2019) and after (May 19, 2019-March 7, 2020). Cumulative incidence analysis estimated the probability of dropout within 1 year of listing decreased from 12.9% before the policy to 11.1% after the policy in candidates without HCC and from 14% to 10.7% in candidates with HCC. Incidence rates of liver transplantation (LT) and waitlist dropout varied significantly before the policy in patients with HCC and without HCC but nearly equalized in the postpolicy era. These effects were observed in both shorter and longer wait regions. With policy change being modeled as a time-dependent covariate, competing risk regression analyses estimated a decreased risk of dropout after policy change in the non-HCC group (cause-specific hazard ratio, 0.91; P = 0.02) after adjusting for demographic variables. These results suggest that the MMAT-3 policy has successfully reduced disparities in access to LT including across UNOS wait regions, although certain patients with HCC are now disadvantaged.

Artificial Intelligence in hepatology, liver surgery and transplantation: Emerging applications and frontiers of research

The integration of artificial intelligence (AI) and augmented realities into the medical field is being attempted by various researchers across the globe. As a matter of fact, most of the advanced technologies utilized by medical providers today have been borrowed and extrapolated from other industries. The introduction of AI into the field of hepatology and liver surgery is relatively a recent phenomenon. The purpose of this narrative review is to highlight the different AI concepts which are currently being tried to improve the care of patients with liver diseases. We end with summarizing emerging trends and major challenges in the future development of AI in hepatology and liver surgery.

Surveillance and Monitoring of Hepatocellular Carcinoma During the COVID-19 Pandemic

The Coronavirus disease 2019 (COVID-19) pandemic is expected to have a long-lasting impact on the approach to care for patients at risk for and with hepatocellular carcinoma (HCC) due to the risks from potential exposure and resource reallocation. The goal of this document is to provide recommendations on HCC surveillance and monitoring, including strategies to limit unnecessary exposure while continuing to provide high-quality care for patients. Publications and guidelines pertaining to the management of HCC during COVID-19 were reviewed for recommendations related to surveillance and monitoring practices, and any available guidance was referenced to support the authors' recommendations when applicable. Existing HCC risk stratification models should be utilized to prioritize imaging resources to those patients at highest risk of incident HCC and recurrence following therapy though surveillance can likely continue as before in settings where COVID-19 prevalence is low and adequate protections are in place. Waitlisted patients who will benefit from urgent LT should be prioritized for surveillance whereas it would be reasonable to extend surveillance interval by a short period in HCC patients with lower risk tumor features and those more than 2 years since their last treatment. For patients eligible for systemic therapy, the treatment regimen should be dictated by the risk of COVID-19 associated with route of administration, monitoring and treatment of adverse events, within the context of relative treatment efficacy.

The Key Role of Staging Definitions for Assessment of Downstaging for Hepatocellular Carcinoma

The success of liver transplant (LT) for hepatocellular carcinoma (HCC) is dependent on accurate tumor staging using validated imaging criteria, and adherence to acceptable criteria based on tumor size and number. Other factors including α-fetoprotein (AFP) and response to local regional therapy (LRT) have now played a larger role in candidate selection. Tumor downstaging is defined as reduction in the size of viable tumors using LRT to meet acceptable criteria for LT, and serves as a selection tool for a subgroup of HCC with more favorable biology. The application of tumor downstaging requires a structured approach involving three key components in tumor staging-initial tumor stage and eligibility criteria, tumor viability assessment following LRT, and target tumor stage prior to LT-and incorporation of AFP into staging and treatment response assessments. In this review, we provide in-depth discussions of the key role of these staging definitions in ensuring successful outcome.

A novel waitlist dropout score for hepatocellular carcinoma - identifying a threshold that predicts worse post-transplant survival

BACKGROUND & AIMS

It has been suggested that patients with hepatocellular carcinoma (HCC) at high risk of wait-list dropout would have done poorly after liver transplantation (LT) because of tumour aggressiveness. To test this hypothesis, we analysed risk of wait-list dropout among patients with HCC in long-wait regions (LWRs) to create a dropout risk score, and applied this score in short (SWRs) and mid-wait regions (MWRs) to evaluate post-LT outcomes. We sought to identify a threshold in dropout risk that predicts worse post-LT outcome.

METHODS

Using the United Network for Organ Sharing database, including all patients with T2 HCC receiving priority listing from 2010 to 2014, a dropout risk score was created from a developmental cohort of 2,092 patients in LWRs, and tested in a validation cohort of 1,735 patients in SWRs and 2,894 patients in MWRs.

RESULTS

On multivariable analysis, 1 tumour (3.1-5 cm) or 2-3 tumours, alpha-fetoprotein (AFP) >20 ng/ml, and increasing Child-Pugh and model for end-stage liver disease-sodium scores significantly predicted wait-list dropout. A dropout risk score using these 4 variables (C-statistic 0.74) was able to stratify 1-year cumulative incidence of dropout from 7.1% with a score ≤7 to 39.5% with a score >23. Patients with a dropout risk score >30 had 5-year post-LT survival of 60.1% vs. 71.8% for those with a score ≤30 (p = 0.004). There were no significant differences in post-LT survival below this threshold.

CONCLUSIONS

This study provided evidence that patients with HCC with the highest dropout risk have aggressive tumour biology that would also result in poor post-LT outcomes when transplanted quickly. Below this threshold risk score of ≤30, priority status for organ allocation could be stratified based on the predicted risks of wait-list dropout without significant differences in post-LT survival.

LAY SUMMARY

Prioritising patients with hepatocellular carcinoma for liver transplant based on risk of wait-list dropout has been considered but may lead to inferior post-transplant survival. In this study of nearly 7,000 patients, we created a threshold dropout risk score based on tumour and liver-related factors beyond which patients with hepatocellular carcinoma will likely have poor post-liver transplant outcomes (60% at 5 years). For patients below this risk score threshold, priority status could be stratified based on the predicted risk of wait-list dropout without compromising post-transplant survival.

Effect of Mandatory 6-Month Waiting Period on Waitlist and Transplant Outcomes in Patients With Hepatocellular Carcinoma

BACKGROUND AND AIMS

Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) policy mandates a 6-month waiting period before exception scores are granted to liver transplant candidates with hepatocellular carcinoma (HCC). This study aims to evaluate waitlist and posttransplant outcomes in patients with HCC, before and after implementation of the 6-month waiting rule.

APPROACH AND RESULTS

We examined two groups from the UNOS registry: Group 1 (pre-6-month rule) consisted of patients registered as transplant candidates with HCC from January 1, 2013, to October 7, 2015 (n = 4,814); group 2 (post-6-month rule) consisted of patients registered from October 8, 2015, to June 30, 2018 (n = 3,287). As expected, the transplant probability was higher in the first 6 months after listing in group 1 than group 2 at 42.0% versus 6.3% (P < 0.001). However, the 6-month waitlist mortality/dropout rate was lower in group 2 at 1.2% than group 1 at 4.1% (P < 0.001). To assess regional parity of transplant, UNOS regions were categorized into three groups based on Model for End-Stage Liver Disease score at transplant: lower-score (regions 3, 10, and 11), middle-score (1, 2, 6, 8, and 9), and higher-score region groups (4, 5, and 7). Outcomes were compared from the time exception points were given, which we defined as conditional waitlist outcomes. Conditional waitlist mortality/dropout decreased, and transplant probability increased in all region groups, but the benefits of the policy were more pronounced in the higher and middle-score groups, compared with the lower-score group. The decline in waitlist mortality/dropout was only significant in the high Model for End-Stage Liver Disease group (P < 0.001). No effect was observed on posttransplant mortality or percent of patients within Milan criteria on explant.

CONCLUSIONS

The HCC policy change was associated with decreased waitlist mortality/dropout and increased transplant probability. The policy helped to decrease but did not eliminate regional disparities in transplant opportunity without an effect on posttransplant outcomes.

Hepatocellular Carcinoma Demonstrates Heterogeneous Growth Patterns in a Multicenter Cohort of Patients With Cirrhosis

BACKGROUND AND AIMS

There are limited data on hepatocellular carcinoma (HCC) growth patterns, particularly in Western cohorts, despite implications for surveillance, prognosis, and treatment. Our study's aim was to quantify tumor doubling time (TDT) and identify correlates associated with indolent and rapid growth.

APPROACH AND RESULTS

We performed a retrospective multicenter cohort study of patients with cirrhosis diagnosed with HCC from 2008 to 2017 at six US and European health systems with two or more contrast-enhanced imaging studies performed ≥ 30 days apart prior to HCC treatment. Radiologists independently measured tumors in three dimensions to calculate TDT and specific growth rate (SGR). We used multivariable ordinal logistic regression to identify factors associated with indolent (TDT > 365 days) and rapid (TDT < 90 days) tumor growth. In the primary cohort (n = 242 patients from four centers), median TDT was 229 days (interquartile range [IQR], 89-627) and median SGR was 0.3% per day (IQR, 0.1%-0.8%). Over one-third (38%) of HCCs had indolent growth, 36.8% intermediate growth, and 25.2% rapid growth. In multivariable analysis, indolent growth was associated with larger tumor diameter (odds ratio [OR], 1.15, 95% confidence interval [CI], 1.03-1.30) and alpha-fetoprotein < 20 ng/mL (OR, 1.90; 95% CI, 1.12-3.21). Indolent growth was more common in nonviral than viral cirrhosis (50.9% versus 32.1%), particularly in patients with T1 HCC (OR, 3.41; 95% CI, 1.08-10.80). Median TDT (169 days; IQR 74-408 days) and SGR (0.4% per day) were similar in an independent cohort (n = 176 patients from two centers).

CONCLUSIONS

In a large Western cohort of patients with HCC, we found heterogeneous tumor growth patterns, with one-fourth exhibiting rapid growth and over one-third having indolent growth. Better understanding different tumor growth patterns may facilitate a precision approach to prognostication and treatment.

A 2020 update on liver transplant for hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma is the most frequent liver tumor and is associated with chronic liver disease in 90% of cases. In selected cases, liver transplantation represents an effective therapy with excellent overall survival.

AREA COVERED

Since the introduction of Milan criteria in 1996, numerous alternative selection systems to LT for HCC patients have been proposed. Debate remains about how best to select HCC patients for transplant and how to prioritize them on the waiting list.

EXPERT OPINION

The selection of the best scoring system to propose in the context of LT for HCC is far to be identified. In this review, we analyze and categorize the various selection systems, assessing their roles in the different decisional phases.

Donation After Circulatory Death Is Associated With Similar Posttransplant Survival in All but the Highest-Risk Hepatocellular Carcinoma Patients

Liver transplantation (LT) recipients with hepatocellular carcinoma (HCC) receive a higher proportion of livers from donation after circulatory death (DCD) donors compared with non-HCC etiologies. Nevertheless, data on outcomes in patients with HCC receiving DCD grafts are limited. We evaluated the influence of DCD livers on post-LT outcome among HCC patients. We identified 7563 patients in the United Network for Organ Sharing (UNOS) database who underwent LT with Model for End-Stage Liver Disease score exceptions from 2012 to 2016, including 567 (7.5%) who received a DCD donor organ and 6996 (92.5%) who received a donation after brain death (DBD) donor organ. Kaplan-Meier probabilities of post-LT HCC recurrence at 3 years were 7.6% for DCD and 6.4% for DBD recipients (P = 0.67) and post-LT survival at 3 years was 81.1% versus 85.5%, respectively (P = 0.008). On multivariate analysis, DCD donor (hazard ratio, 1.38; P = 0.005) was an independent predictor of post-LT mortality. However, a survival difference after LT was only observed in subgroups at higher risk for HCC recurrence including Risk Estimation of Tumor Recurrence After Transplant (RETREAT) score ≥4 (DCD 57.0% versus DBD 72.6%; P = 0.02), alpha-fetoprotein (AFP) ≥100 (60.1% versus 76.9%; P = 0.049), and multiple viable tumors on last imaging before LT (69.9% versus 83.1%; P = 0.002). In this analysis of HCC patients receiving DCD versus DBD livers in the UNOS database, we found that patients with a low-to-moderate risk of HCC recurrence (80%-90% of the DCD cohort) had equivalent survival regardless of donor type. It appears that DCD donation can best be used to increase the donor pool for HCC patients with decompensated cirrhosis or partial response/stable disease after locoregional therapy with AFP at LT <100 ng/mL.

HEPATOCELLULAR CARCINOMA PATIENTS ARE ADVANTAGED IN THE CURRENT BRAZILIAN LIVER TRANSPLANT ALLOCATION SYSTEM. A COMPETING RISK ANALYSIS

BACKGROUND

In Brazil, the Model for End-Stage Liver Disease (MELD) score is used to prioritize patients for deceased donor liver transplantation (DDLT). Patients with hepatocellular carcinoma (HCC) receive standardized MELD exception points to account for their cancer risk of mortality, which is not reflected by their MELD score.

OBJECTIVE

To compare DDLT rates between patients with and without HCC in Rio Grande do Sul, the Southernmost state of Brazil.

METHODS

- We retrospectively studied 825 patients on the liver-transplant waiting list from January 1, 2007, to December 31, 2016, in a transplant center located in Porto Alegre, the capital of Rio Grande do Sul, to compare DDLT rates between those with and without HCC. The time-varying hazard of waiting list/DDLT was estimated, reporting the subhazard ratio (SHR) of waiting list/DDLT/dropout with 95% confidence intervals (CI). The final competing risk model was adjusted for age, MELD score, exception points, and ABO group.

RESULTS

Patients with HCC underwent a transplant almost three times faster than patients with a calculated MELD score (SHR 2.64; 95% CI 2.10-3.31; P<0.001). The DDLT rate per 100 person-months was 11.86 for HCC patients vs 3.38 for non-HCC patients. The median time on the waiting list was 5.6 months for patients with HCC and 25 months for patients without HCC.

CONCLUSION

Our results demonstrated that, in our center, patients on the waiting list with HCC have a clear advantage over candidates listed with a calculated MELD score.

Hepatocellular Carcinoma-How to Determine Therapeutic Options

Deciding on specific treatment strategies involves not only tumor stage, performance status, and severity of underlying liver disease, but additional factors such as biomarkers, organ availability, and radiographic tumor response to treatment. In this review, we present hepatocellular carcinoma (HCC) cases to highlight how to determine therapeutic options for HCC in specific scenarios, including resection versus liver transplant, choice of initial local regional treatment, tumor downstaging, and systemic therapies for advanced HCC.