Sex Disparity in Liver Transplant and Access to Living Donation

A scoping review of nonmedical barriers to living donor liver transplant

This study aims to identify and categorize nonmedical barriers encountered by recipients, donors, and health care providers in the context of living donor liver transplantation (LDLT). Liver transplantation is vital for individuals with liver failure, yet high mortality rates on the transplant waitlist persist. LDLT was introduced to address deceased donor organ shortages; however, its adoption varies widely across regions, prompting the need to explore barriers hindering its implementation. The scoping review employed inclusion and exclusion criteria to identify studies focusing on nonmedical barriers to LDLT in both adult and pediatric populations. Qualitative, quantitative, and mixed-method studies were considered, covering the period from January 2005 to February 2023. The review's search strategy was conducted in the Ovid MEDLINE and Ovid EMBASE databases. Studies meeting the criteria were assessed for their characteristics and findings, which were synthesized into recipient, donor, and provider-level barriers. Among 2394 initially screened articles, 17 studies were eligible for inclusion. Recipient-level barriers encompassed systemic disparities in access, limited social support, immigration status, and inadequate awareness of LDLT. Donor-level barriers involved surgery-related risks, recovery time concerns, financial burdens, and religious beliefs. Provider-level barriers highlighted institutional support inadequacies and specialized surgeon shortages. The scoping review underscores nonmedical barriers to LDLT across recipient, donor, and provider levels. These barriers include socioeconomic disparities, information gaps, and inadequate institutional support. The findings underscore the need for comprehensive national efforts to raise awareness about LDLT and provide essential financial support.

Liver Transplantation for Hepatocellular Carcinoma: An Expanding Cornerstone of Care in the Era of Immunotherapy

Liver transplantation (LT) has been accepted as a cornerstone of care in hepatocellular carcinoma (HCC) for almost three decades. In recent years, its role has been evolving to include patients with disease burden beyond the widely used Milan criteria. The integration of dynamic biomarkers such as alpha-fetoprotein together with downstaging approaches and tumor evolution after enlistment has allowed the selection of patients most likely to benefit, resulting in 5-year survival rates greater that 70%. With the increasing use of immune checkpoint inhibitors (ICIs) across all stages of disease, alone or in combination with locoregional therapies, there is now the potential to further expand the patient population with HCC who may benefit from LT. This brings challenges, given the global shortage of organs and the need to better understand the optimal use of ICIs before transplantation. Furthermore, the field of transplant oncology awaits additional biomarkers that can predict those likely to benefit from ICIs. More than ever, a multidisciplinary approach for liver cancer management is critical to ensure all patients are considered for LT where appropriate, and do not miss the opportunity for long-term survival.

The importance of equity in transplant oncology

PURPOSE OF REVIEW

Transplant oncology encompasses and utilizes liver transplantation (LT) in combination with other aspects of cancer care to offer improved long-term outcomes for patients with liver cancer, but not all patients have equal access and ability to undergo LT. Social determinants of health may negatively impact a patient's ability to receive liver-related oncologic care, including LT. This review highlights recent work exposing gaps in access to LT, including transplant oncology, and interventions to ameliorate these disparities.

RECENT FINDINGS

Members of racial and ethnic minorities and indigenous groups, females, socioeconomically disadvantaged persons, and patients from rural areas are less likely to undergo LT. Recent studies have also described programs that have successfully mitigated some of the barriers in access to transplant oncology that these patients experience, including targeted outreach programs and access to virtual healthcare.

SUMMARY

Disparities in access to LT for liver cancer are increasingly well described, but additional research is needed to find effective ways to ameliorate these differences.

EASL Clinical Practice Guidelines on liver transplantation

Liver transplantation (LT) is an established life-saving procedure. The field of LT has changed in the past 10 years from several perspectives, with the expansion of indications, transplantation of patients with acute-on-chronic liver failure, evolution of transplant oncology, the use of donations after cardiac death, new surgical techniques, and prioritisation of recipients on the waiting list. In addition, the advent of organ perfusion machines, the recognition of new forms of rejection, and the attention paid to the transition from paediatric to adult patients, have all improved the management of LT recipients. The purpose of the EASL guidelines presented here is not to cover all aspects of LT but to focus on developments since the previous EASL guidelines published in 2016.

Sex-based Disparities in Liver Transplantation for Hepatocellular Carcinoma and the Impact of the Growing Burden of NASH

Background

The cause of liver disease is changing, but its impact on liver transplantation (LT) for hepatocellular carcinoma (HCC) in women and men is unclear. We performed a nationwide study to assess the prevalence and posttransplant survival outcomes of the various causes of liver disease in women and men with HCC.

Methods

Data were obtained from the United Network for Organ Sharing database from 2000 to 2022. Data related to the listing, transplant, waitlist mortality, and posttransplant mortality for HCC were extracted. The proportion of HCC related to the various causes of liver disease among LT candidates and recipients and posttransplant survival were compared between women and men.

Results

A total of 51 721 individuals (39 465 men, 12 256 women) with HCC were included. From 2000 to 2022, nonalcoholic steatohepatitis (NASH) was the fastest-growing cause of liver disease among female LT candidates with HCC (P < 0.01), followed by alcohol-associated liver disease. NASH overtook chronic hepatitis C as the leading cause of liver disease in 2020 and 2022 among waitlisted women and men with HCC, respectively. Female patients with HCC spent a significantly longer time on the LT waitlist compared with male patients (β: 8.73; 95% confidence interval [CI], 2.91-14.54). Female patients with HCC from alcohol-associated liver disease also have a lower probability of receiving LT (subdistribution hazard ratio: 0.90; 95% CI, 0.82-0.99). Among transplant recipients with NASH HCC, female sex was associated with lower posttransplant mortality compared with male sex (hazard ratio: 0.79; 95% CI, 0.70-0.89; P < 0.01).

Conclusions

Women have a significantly longer waitlist duration compared with men. NASH is now the leading cause of liver disease among both female and male LT candidates and recipients with HCC.

Exploiting gender-based biomarkers and drug targets: advancing personalized therapeutic strategies in hepatocellular carcinoma

This review systematically examines gender differences in hepatocellular carcinoma (HCC), identifying the influence of sex hormones, genetic variance, and environmental factors on the disease's epidemiology and treatment outcomes. Recognizing the liver as a sexually dimorphic organ, we highlight how gender-specific risk factors, such as alcohol consumption and obesity, contribute differently to hepatocarcinogenesis in men and women. We explore molecular mechanisms, including the differential expression of androgen and estrogen receptors, which mediate diverse pathways in tumor biology such as cell proliferation, apoptosis, and DNA repair. Our analysis underscores the critical need for gender-specific research in liver cancer, from molecular studies to clinical trials, to improve diagnostic accuracy and therapeutic effectiveness. By incorporating a gender perspective into all facets of liver cancer research, we advocate for a more precise and personalized approach to cancer treatment that acknowledges gender as a significant factor in both the progression of HCC and its response to treatment. This review aims to foster a deeper understanding of the biological and molecular bases of gender differences in HCC and to promote the development of tailored interventions that enhance outcomes for all patients.

Sex and racial disparities in living donor liver transplantation in the United States

Sex and racial disparities in deceased donor liver transplantation (DDLT) have been described, but this has not been well studied in living donor liver transplantation (LDLT). We aim to examine these disparities in the US LDLT population and identify potential predictors of these differences. From 2002 to 2021, the Organ Procurement and Transplant Network database was queried to characterize the adult LDLT population and evaluate differences between LDLT and DDLT recipients with regard to sex and race. Donor demographics, Model for End-stage Liver Disease (MELD), and socioeconomic data were all included. Of the 4961 LDLT and 99,984 DDLT recipients, males received the majority of LDLT (55% vs. 45%, p < 0.001) and DDLT (67% vs. 33%, p < 0.001) compared to females. There was a significant difference in race between male and female LDLT recipients ( p < 0.001); 84% of male recipients were White and 78% of females. In both groups, females had lower levels of education and were less likely to have private insurance. There were more female living donors (N = 2545, 51%); 50% of female donors donated to males but only 40% of males donated to females. Donor-recipient relationships varied significantly by sex ( p < 0.001); males received more donations from spouses (62% vs. 39%) and siblings (60% vs. 40%). In the LDLT population, significant disparities exist with respect to sex and race that disadvantage women, but these disparities are less pronounced than in the DDLT population. Although further studies are needed, complex clinical and socioeconomic differences as well as donor factors may explain these variations.

Biliary atresia and liver transplantation in the United States: A contemporary analysis

BACKGROUND

Biliary atresia (BA) remains the number one indication for paediatric liver transplantation (LT) worldwide but is an uncommon indication for older LT recipients. The impact of recent donor allocation changes, pervasive organ shortage and evolving LT practices on the BA LT population is unknown.

METHODS

We identified patients who underwent LT between January 2010 and December 2021 using the UNOS database. We compared clinical outcomes between patients with BA and those with non-BA cholestatic liver disease. Groups were stratified by age, <12 years (allocated via PELD system) and ≥12 years (allocated via MELD system). Waitlist outcomes were compared using competing-risk regression analysis, graft survival rates were compared using Kaplan-Meier time-to-event analysis and Cox proportional hazards modelling provided adjusted estimates.

RESULTS

There were 2754 BA LT waitlist additions and 2206 BA LTs (1937 <12 years [younger], 269 ≥12 years [older]). There were no differences in waitlist mortality between BA and non-BA cholestatic patients. Among BA LT recipients, there were 441 (20.0%) living-donor liver transplantations (LDLT) and 611 (27.7%) split deceased-donor LTs. Five-year graft survival was significantly higher among BA versus non-BA cholestatic patients in the older group (88.3% vs. 79.5%, p < .01) but not younger group (89.3% vs. 89.5%). Among BA LT recipients, improved graft outcomes were associated with LDLT (vs. split LT: HR: 2, 95% CI: 1.03-3.91) and higher transplant volume (volume >100 vs. <40 BA LTs: HR: 3.41, 95% CI: 1.87-6.2).

CONCLUSION

Liver transplant outcomes among BA patients are excellent, with LDLT and higher transplant centre volume associated with optimal graft outcomes.

Availability of living donor optimizes timing of liver transplant in high-risk waitlisted cirrhosis patients

Liver transplant (LT) candidates have become older and frailer, with growing Non-alcoholic steatohepatitis (NASH) and comorbid disease burden in recent years, predisposing them for poor waitlist outcomes. We aimed to evaluate the impact of access to living donor liver transplantation (LDLT) in waitlisted patients at highest risk of dropout. We reviewed all adult patients with decompensated cirrhosis listed for LT from November 2012 to December 2018. Patients with a potential living donor (pLD) available were identified. Survival analyses with Cox Proportional Hazards models and time to LT with Competing risk models were performed followed by prediction model development. Out of 860 patients who met inclusion criteria, 360 (41.8%) had a pLD identified and 496 (57.6%) underwent LT, out of which 170 (34.2%) were LDLT. The benefit of pLD was evident for all, but patients with moderate to severe frailty at listing (interaction p = 0.03), height <160 cm (interaction p = 0.03), and Model for end stage liver disease (MELD)-Na score <20 (interaction p < 0.0001) especially benefited. Our prediction model identified patients at highest risk of dropout while waiting for deceased donor and most benefiting of pLD (time-dependent area under the receiver operating characteristic curve 0.82). Access to LDLT in a transplant program can optimize the timing of transplant for the increasingly older, frail patient population with comorbidities who are at highest risk of dropout.

Living donor liver transplantation can address disparities in transplant access for patients with primary sclerosing cholangitis

BACKGROUND

Liver transplantation (LT) is frequently lifesaving for people living with primary sclerosing cholangitis (PSC). However, patients are waitlisted for LT according to the model for end-stage liver disease-sodium (MELD-Na) score, which may not accurately reflect the burden of living with PSC. We sought to describe and analyze the clinical trajectory for patients with PSC referred for LT, in a mixed deceased donor/living donor transplant program.

METHODS

This was a retrospective cohort study from November 2012 to December 2019, including all patients with PSC referred for assessment at the University Health Network Liver Transplant Clinic. Patients who required multiorgan transplant or retransplantation were excluded. Liver symptoms, hepatobiliary malignancy, MELD-Na progression, and death were abstracted from chart review. Competing risk analysis was used for timing of LT, transplant type, and death.

RESULTS

Of 172 PSC patients assessed, 84% (n = 144) were listed of whom 74% were transplanted. Mean age was 47.6 years, and 66% were male. Overall mortality was 18.2% at 2 years. During the follow-up, 16% (n = 23) were removed from the waitlist for infection, clinical deterioration, liver-related mortality or new cancer; 3 had clinical improvement. At listing, 82% (n = 118) had a potential living donor (pLD). Patients with pLD had significantly lower waitlist and liver-related waitlist mortality (HR 0.20, p<0.001 and HR 0.17, p<0.001, respectively), and higher rates of transplantation (HR 1.83, p = 0.05). Exception points were granted to 13/172 (7.5%) patients.

CONCLUSIONS

In a high-volume North American LT center, most patients with PSC assessed for transplant were listed and subsequently transplanted. However, this was a consequence of patients engaging in living donor transplantation. Our findings support the concern from patients with PSC that MELD-Na allocation does not adequately address their needs.

Addressing sex-based disparities in liver transplantation

PURPOSE OF REVIEW

Disparities in access to liver transplantation by sex have been well described, disadvantaging women. Understanding the multifactorial causes of these disparities as well as the variety of proposed solutions is critical to improving access to this life-saving intervention for women. This review aims to summarize the current body of evidence on observed sex disparities in liver transplantation and highlight actionable, evidence-based mechanisms by which these disparities can be addressed.

RECENT FINDINGS

Strategies for addressing sex disparities in liver transplantation include increasing organ utilization, changing allocation policy, and leveraging public policies to reduce the incidence of end-stage liver disease. Several other promising interventions are currently being explored.

SUMMARY

In the United States, women face additional barriers to liver transplantation on the basis of sex. Immediate action is necessary to systematically address these inequities.

Current status of disparity in liver disease

Disparities have emerged as an important issue in many aspects of healthcare in developed countries and may be based on race, ethnicity, sex, geographical location, and socioeconomic status. For liver disease specifically, these potential disparities can affect access to care and outcome in viral hepatitis, chronic liver disease, and hepatocellular carcinoma. Shortages in hepatologists and medical providers versed in liver disease may amplify these disparities by compromising early detection of liver disease, surveillance for hepatocellular carcinoma, and prompt referral to subspecialists and transplant centers. In the United States, continued efforts have been made to address some of these disparities with better education of healthcare providers, use of telehealth to enhance access to specialists, reminders in electronic medical records, and modifying organ allocation systems for liver transplantation. This review will detail the current status of disparities in liver disease and describe current efforts to minimize these disparities.

The fundamentals of sex-based disparity in liver transplantation: Understanding can lead to change

Liver transplantation (LT) is the definitive treatment for end-stage liver disease. Unfortunately, women are disadvantaged at every stage of the LT process. We conducted a literature review to increase the understanding of this disparity. Hormonal differences, psychological factors, and Model for End-Stage Liver Disease (MELD) score inequalities are some pretransplantation factors that contribute to this disparity. In the posttransplantation setting, women have differing risk than men in most major outcomes (perioperative complications, rejection, long-term renal dysfunction, and malignancy) and assessing the two groups together is disadvantageous. Herein, we propose interventions including standardized criteria for LT referral, using an alternate MELD, education for support of women, and motivating women to seek living donors. Understanding sex-based differences will allow us to improve access, tailor management, and improve overall outcomes for all patients, particularly women.