The Impact of Allocation Changes on Patients with Hepatocellular Carcinoma

Pre-transplant Loco-Regional Therapy for Hepatocellular Carcinoma and Post-transplant Outcomes: A National Study

The ultimate preferred treatment for hepatocellular carcinoma (HCC) complicated with cirrhosis and portal hypertension is an orthotopic liver transplant (OLT). Loco regional therapy (LRT) has emerged to prevent tumor growth and progression of disease beyond the Milan criteria to achieve transplant. There is a paucity of data regarding safety, posttransplant survival benefits, and tumor recurrence rate achieved by these LRT modalities. We aim to assess and compare the five-year survival rate and tumor recurrence rate with or without LRT in patients after OLT with diagnosed HCC utilizing the nation's largest dataset. This is a retrospective observational study approved by Saint Louis University institutional review board. We utilized the largest dataset from the years 2003-2013 where pertaining data were gathered from Organ Procurement Transplant Network (OPTN) standard analysis and research files (STAR) through novel linkages with Medicare bills. Descriptive and comparative statistics were performed. 2412 (51.6%) patients received any form of locoregional therapy (single or combination) out of 4669 total study sample size. The overall five-year survival in the study sample was 76.1%. There was statistically no significant improvement seen in five-year posttransplant survival in the group that received one mode of LRT (adjusted hazard ratio (aHR) 0.97, P<0.64) or a combination of LRT (aHR 0.94, P<0.58) in comparison to those that received none after adjusting donor and recipient clinical characteristics. However, five-year survival trended higher among those treated with combination therapy over those treated with single LRT or none. Overall HCC recurrence was 4.8%, while no significant difference was noted when comparing above-mentioned groups. Five-year posttransplant survival and HCC recurrence rate were also found to have no difference when compared between above-mentioned groups after adjusting explant pathology. This is the largest retrospective study comparing liver transplant patients with HCC who received LRT to none. Although it did not show any statistically significant benefit of single or combination of LRT on survival or tumor recurrence after liver transplant for HCC patients, the outcomes encourage the safe and feasible use of LRT as a bridging therapy. Our study also suggests an observed pattern of improved posttransplant survival and tumor recurrence rate with combination loco-regional therapy. Larger multicenter prospective studies will be required to achieve the effect size to determine the best therapies for maximizing patient survival cost-effectively.

Outcomes of liver transplantation in non-alcoholic steatohepatitis (NASH) versus non-NASH associated hepatocellular carcinoma

BACKGROUND

Non-alcoholic steatohepatitis (NASH)-associated hepatocellular carcinoma (HCC) is a rising indication for liver transplantation. This unique population, with multiple comorbidities, has potential for worse post-transplant outcomes. We compared post-transplant survival of NASH and non-NASH HCC patients using a large cohort.

METHODS

Adults transplanted for HCC between 2008 and 2018, from United Network for Organ Sharing (UNOS) and University Health Network (UHN) databases were divided into two populations: NASH and non-NASH. Recipient characteristics and post-transplant survival were compared. Subgroup analyses were performed within and beyond Milan criteria.

RESULTS

2071 of 20,672 (10.0%) patients underwent transplantation for NASH HCC, with annual proportional increase of 1.2%UHN (p = 0.02) and 1.3%UNOS (p < 0.001). The 1-,3-,5-year post-transplant survival were 90.8%, 83.9%, 76.3% NASH HCC versus 91.9%, 82.1%, 74.9% non-NASH HCC (p = 0.94). No survival differences were observed in populations within or beyond Milan. Competing-risk analysis demonstrated no differences in risk for cardiovascular-related death (HR1.24, 95%CI 0.87-1.55, p = 0.16), or HCC recurrence-related death (HR1.21, 95%CI 0.89-1.65, p = 0.23). NASH HCC patients had lower risk of liver-related deaths (HR0.57, 95%CI 0.34-0.98, p = 0.04).

DISCUSSION

NASH HCC is a rising indication for liver transplantation. Despite demographic differences, no post-transplantation survival differences were observed between NASH and non-NASH HCC. This justifies equivalent organ allocation, irrespective of NASH status.

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.

Status 1B designation does not adequately prioritize children with acute-on-chronic liver failure for liver transplantation

Acute-on-chronic liver failure (ACLF) is an acute decompensation of chronic liver disease leading to multiorgan failure and mortality. The objective of this study was to evaluate characteristics and outcomes of children with ACLF who are at the highest priority for liver transplantation (LT) on the United Network for Organ Sharing (UNOS) database-listed as status 1B. The characteristics and outcomes of 478 children with ACLF listed as status 1B on the UNOS LT waiting list from 2007-2019 were compared with children with similar or higher priority listing for transplant: 929 with acute liver failure (ALF) listed as status 1A and 808 with metabolic diseases and malignancies listed as status 1B (termed "non-ACLF"). Children with ACLF had comparable rates of cumulative organ failures compared with ALF (45% vs. 44%; p > 0.99) listings, but higher than non-ACLF (45% vs. 1%; p < 0.001). ACLF had the lowest LT rate (79%, 84%, 95%; p < 0.001), highest pre-LT mortality (20%, 11%, 1%; p < 0.001), and longest waitlist time (57, 3, 56 days; p < 0.001), and none recovered without LT (0%, 4%, 1%; p < 0.001). In survival analyses, ACLF was associated with an increased adjusted hazard ratio (HR) for post-LT mortality (HR, 1.50 vs. ALF [95% confidence interval, CI, 1.02-2.19; p = 0.04] and HR, 1.64 vs. non-ACLF [95% CI, 1.15-2.34; p = 0.01]). ACLF has the least favorable waitlist and post-LT outcomes of all patients who are status 1A/1B. Increased prioritization on the LT waiting list may offer children with ACLF an opportunity for enhanced outcomes.

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

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.

National Trends and Waitlist Outcomes of Locoregional Therapy Among Liver Transplant Candidates With Hepatocellular Carcinoma in the United States

BACKGROUND & AIMS

Policy changes in the United States have lengthened overall waiting times for patients with hepatocellular carcinoma (HCC). We investigated temporal trends in utilization of locoregional therapy (LRT) and associated waitlist outcomes among liver transplant (LT) candidates in the United States.

METHODS

Data for primary adult LT candidates listed from 2003 to 2018 who received HCC exception were extracted from the Organ Procurement and Transplantation Network database. Explant histology was examined, and multivariable competing risk analysis was used to evaluate the association between LRT type and waitlist dropout.

RESULTS

There were 31,609 eligible patients with at least 1 approved HCC exception, and 34,610 treatments among 24,145 LT candidates. The proportion with at least 1 LRT recorded increased from 42.3% in 2003 to 92.4% in 2018. Chemoembolization remains the most frequent type, followed by thermal ablation, with a notable increase in radioembolization from 3% in 2013 to 19% in 2018. An increased incidence of LRT was observed among patients with tumor burden beyond Milan criteria, higher α-fetoprotein level, and more compensated liver disease. Receipt of any type of LRT was associated with a lower risk of waitlist dropout; there was no significant difference by number of LRTs. In inverse probability of treatment weighting-adjusted analysis, radioembolization or ablation as the first LRT was associated with a reduced risk of waitlist dropout compared with chemoembolization.

CONCLUSIONS

In a large nationwide cohort of LT candidates with HCC, LRT, and in particular radioembolization, increasingly was used to bridge to LT. Patients with greater tumor burden and those with more compensated liver disease received more treatments while awaiting LT. Bridging LRT was associated with a lower risk of waitlist dropout.

Oncologic indications of liver transplantation and deceased donor liver allocation in the United States

PURPOSE OF REVIEW

Liver transplantation is a standard therapy for certain liver cancers. The majority of liver transplantation in the United States is through deceased donor liver transplantation (DDLT). A significant disparity between the demand of livers and patients awaiting liver transplantation still remains, relying on United Network for Organ Sharing (UNOS) to make policies to determine priority amongst recipients, including for patients with liver cancer. We review the scope of liver transplantation in patients with liver cancer with a focus on hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (iCCA), and unresectable colorectal liver metastases (CRLM) with respect to current liver allocation policy.

RECENT FINDINGS

Recently, liver allocation changed in the United States. Under the current allocation policy, select patients with HCC and hilar CCA (hCCA) receive priority with an exception score of median MELD score at transplant (MMAT)-3. There is scope for other liver cancers, such as iCCA and CRLM to be considered, as reasonable outcomes have been achieved in these patients outside of the United States through DDLT and living donor liver transplantation (LDLT).

SUMMARY

With the growing experience of liver transplantation for nonconventional oncologic indications, the current policy for prioritization of liver cancer within deceased donor liver allocation may need to be re-evaluated.