Recent advances in liver transplantation for cancer: The future of transplant oncology

Liver transplantation for intrahepatic cholangiocarcinoma: who, when and how

PURPOSE OF REVIEW

Using transplant oncology principles, selected patients with intrahepatic cholangiocarcinoma (iCCA) may achieve long-term survival after liver transplantation. Strategies for identifying and managing these patients are discussed in this review.

RECENT FINDINGS

Unlike initial reports, several modern series have reported positive outcomes after liver transplantation for iCCA. The main challenges are in identifying the appropriate candidates and graft scarcity. Tumor burden and response to neoadjuvant therapies have been successfully used to identify favorable biology in unresectable cases. New molecular biomarkers will probably predict this response in the future. Also, new technologies and better strategies have been used to increase graft availability for these patients without affecting the liver waitlist.

SUMMARY

Liver transplantation for the management of patients with unresectable iCCA is currently a reality under strict research protocols. Who is a candidate for transplantation, when to use neoadjuvant and locoregional therapies, and how to increase graft availability are the main topics of this review.

Current Status of Liver Transplantation in North America

Liver transplantation indications continue to evolve in North America. Several recent changes have occurred in the field with changes in the allocation system, new performance metrics, expansion of transplant oncology, and utilization of ex vivo perfusion devices and techniques. Deceased donor liver transplantation continues to be the primary modality of liver transplantation in North America, with an ongoing focus on advancing the use of living donor liver transplantation, especially in those patients who may not have favorable access to deceased donor allografts.

Preliminary study of donor volume changes after dual-graft liver transplantation in rats

Dual-graft liver transplantation (DGLT) expands the pool of donors, ensures the safety of the donors, and treats a potential small for size syndrome (SFSS). However, some of the recipient graft showed atrophy. The cause and mechanism of the unbalanced proliferation and atrophy of dual grafts after clinical DGLT have not been clarified. We established and optimized the rat model of DGLT to explore the causes of growth unbalance. Continuously and dynamically observed bilateral graft volume and portal vein blood flow change by magnetic resonance imaging (MRI) and ultrasound (US). We detected liver function indexes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IBIL). Liver samples from receptors were obtained for morphology, and apoptosis was measured by RT-PCR and western blot. Optimization of the model improved the 7-day survival rate from former 58.3% to 87.5%, and the 30-day survival rate was 68.8%. The volume of the right graft gradually increased, and the left graft atrophied during the 30-day observation period. The portal blood flow of the left graft gradually decreased until the 30th day (0.13 ± 0.01 ml/s) compared with the sham group (0.63 ± 0.05 ml/s), and the right graft significantly increased on the 30th day (0.75 ± 0.11ml/s). The liver function initially increased and then recovered. The total volume (12.52 ± 1.60 ml vs 4.47 ± 0.08 ml) and weight (12.09 ± 1 g vs 4.91 ± 0.18 g) of the graft increased significantly compared to pre-transplantation and reached the level of the sham operation group on the 30th day. The volume and weight of the right graft increased more than those of the left graft (P < 0.05). There was more inflammatory cell infiltration in the left graft, and the right graft had obvious proliferation of hepatocytes and mature bile duct cells. Left grafts were more prone to apoptosis than right grafts (P < 0.05). In conclusion, growth of the right graft is superior to the left; after double liver transplantation, perfusion blood flow and apoptosis may be the reason contributing to the volume differences in dual grafts.

An Insight into miR-1290: An Oncogenic miRNA with Diagnostic Potential

For more than two decades, the view of the roles of non-coding RNAs (ncRNAs) has been radically changing. These RNA molecules that are transcribed from our genome do not have the capacity to encode proteins, but are critical regulators of gene expression at different levels. Our knowledge is constantly enriched by new reports revealing the role of these new molecular players in the development of many pathological conditions, including cancer. One of the ncRNA classes includes short RNA molecules called microRNAs (miRNAs), which are involved in the post-transcriptional control of gene expression affecting various cellular processes. The aberrant expression of miRNAs with oncogenic and tumor-suppressive function is associated with cancer initiation, promotion, malignant transformation, progression and metastasis. Oncogenic miRNAs, also known as oncomirs, mediate the downregulation of tumor-suppressor genes and their expression is upregulated in cancer. Nowadays, miRNAs show promising application in diagnosis, prediction, disease monitoring and therapy response. Our review presents a current view of the oncogenic role of miR-1290 with emphasis on its properties as a cancer biomarker in clinical medicine.

Liver Transplantation in Malignancies: A Comprehensive and Systematic Review on Oncological Outcome

Introduction

Liver transplantation (LT) is today's standard treatment for both end-stage liver disease and tumors; however, suitable grafts for LT are a scarce resource and outcome after LT is highly dependent on its underlying indication. Thus, patients must be carefully selected to optimize the number of life years gained per graft. This comprehensive and systematic review critically reflects the most recently published oncological outcome data after LT in malignancies based on the preoperative radiological findings.

Methods

A systematic literature search was conducted to detect preferentially most recent high-volume series or large database analysis on oncological outcomes after LT for both primary liver cancer and liver metastases between January 1, 2019, and November 14, 2020. A comprehensive review on the radiological assessment of the reviewed liver malignancies is included and its preoperative value for an outcome-driven indication reflected.

Results

Twenty most recent high-volume or relevant studies including a total number of 2,521 patients were identified including 4, 4, 4, 4, 3, and 1 publications on oncological outcome after LT for hepatocellular carcinoma, cholangiocellular carcinoma, hepatic epitheloid hemangioendothelioma, hepatoblastoma, and both metastatic neuroendocrine tumors and colorectal cancer, respectively. The overall survival is comparable to patients without tumors if patients with malignancies are well selected for LT; however, this is highly dependent on tumor entity, tumor stage, and both neoadjuvant and concomitant treatment.

Discussion/Conclusion

LT is a promising option for better survival in patients with malignant liver tumors in selected patients; however, the indication must be critically discussed prior to LT in every single case in the context of organ shortage.

Colon Rectal Liver Metastases: The Role of the Liver Transplantation in the Era of the Transplant Oncology and Precision Medicine

The development of liver metastases in colon rectal cancer has a strong impact on the overall survival (OS) of the patient, with a 5-year survival rate of 5% with palliative treatment. Surgical resection combined with pharmacological treatment can achieve a 5-year OS rate of 31-58%. However, in only 20% of patients with colon rectal liver metastases (CRLMs), liver resection is feasible. In highly selected patients, recent trials and studies proved that liver transplantation (LT) for non-resectable CRLM is a surgical option with an excellent long-term OS. The paper aims to review the indications and outcome of LT for CRLMs, with a special focus on immunosuppressive therapy and the management of local and extrahepatic recurrence after LT.

Trials & Tribulations of Liver Transplantation- are trials now prohibitive without surrogate endpoints?

During the past 5 decades, liver transplantation has moved from its pioneering days where success was measured in days to a point where it is viewed as a routine part of medical care. Despite this progress, there are still significant unmet needs and outstanding questions that need addressing in clinical trials to improve outcomes for patients. The traditional endpoint for trials in liver transplantation has been 1-year patient survival, but with rates now approaching 95%, this endpoint now poses a number of significant financial and logistical barriers to conducting trials because of the large numbers of participants required to demonstrate only an incremental improvement. Here, we suggest the following solutions to this challenge: adoption of validated surrogate endpoints; bigger and better collaborative multiarm, multiphase studies; recognition by funders and institutions that work on larger collaborative research projects is potentially more important than smaller, self-led bodies of work; ringfenced areas of research within trial frameworks where individuals can take a lead; and fair funding structures using both industry and public sector money across national and international borders.

Liver Transplantation Selection and Allocation Criteria for Hepatocellular Carcinoma: A European Perspective

For patients with early-stage hepatocellular carcinoma (HCC), liver transplantation offers the best chance of cure. Over the past two decades, selection criteria to determine eligibility for liver transplantation have been constantly refined but a fair allocation strategy of liver grafts to HCC patients remains challenging. In Europe, over a dozen transplantation networks apply different liver transplantation criteria for HCC patients. In this review, we explore and compare candidate selection and liver graft allocation strategies for patients with HCC with a European perspective and discuss the ethical and technical challenges involved. In addition, we suggest possible paths for future improvement such as transitioning from fixed selection and allocation criteria to a more flexible model of benefit, which includes criteria concerning the graft, response to treatment, the biology of the tumor, and other relevant recipient factors.

Salvage liver transplantation after resection of colorectal cancer liver metastasis with favorable outcomes: a case report and review of the literature

Background

Approximately 50% of patients with colorectal cancer (CRC) develop metastases most commonly in the liver. Liver transplantation (LT) can be used in certain cases of primary liver malignancy or in metastatic diseases, such as Neuroendocrine tumors. However, there are controversies regarding LT as a treatment option for liver metastasis from CRC due to poor outcomes in previously reported cases.

Case presentation

We report a 37-year-old male who underwent resection of the left-sided colon due to cancer and was found to have synchronous liver metastasis for which he received chemotherapy. Later, he underwent a right hepatectomy, which was complicated by insufficient liver remnant function despite the preserved liver perfusion. Therefore, salvage liver transplantation was performed successfully with a good long-term outcome.

Conclusions

Many studies examined the survival and quality of life in patients undergoing liver transplantation for unresectable colorectal liver metastasis; these studies include the SECA Study (secondary cancer) and others with favorable outcomes. We reviewed the literature and compared the outcomes of some of these studies in this article. Our case emphasizes that liver transplantation could be an option for some colon cancer liver metastasis (CLM) patients, specifically, as a salvage procedure. Thus, more research is needed to develop selection criteria for patients who may benefit from liver transplantation.

Multicenter validation of the liver graft assessment following transplantation (L-GrAFT) score for assessment of early allograft dysfunction

BACKGROUND & AIMS

Early allograft dysfunction (EAD) following liver transplantation (LT) negatively impacts graft and patient outcomes. Previously we reported that the liver graft assessment following transplantation (L-GrAFT₇) risk score was superior to binary EAD or the model for early allograft function (MEAF) score for estimating 3-month graft failure-free survival in a single-center derivation cohort. Herein, we sought to externally validate L-GrAFT₇, and compare its prognostic performance to EAD and MEAF.

METHODS

Accuracies of L-GrAFT₇, EAD, and MEAF were compared in a 3-center US validation cohort (n = 3,201), and a Consortium for Organ Preservation in Europe (COPE) normothermic machine perfusion (NMP) trial cohort (n = 222); characteristics were compared to assess generalizability.

RESULTS

Compared to the derivation cohort, patients in the validation and NMP trial cohort had lower recipient median MELD scores; were less likely to require pretransplant hospitalization, renal replacement therapy or mechanical ventilation; and had superior 1-year overall (90% and 95% vs. 84%) and graft failure-free (88% and 93% vs. 81%) survival, with a lower incidence of 3-month graft failure (7.4% and 4.0% vs. 11.1%; p <0.001 for all comparisons). Despite significant differences in cohort characteristics, L-GrAFT₇ maintained an excellent validation AUROC of 0.78, significantly superior to binary EAD (AUROC 0.68, p = 0.001) and MEAF scores (AUROC 0.72, p <0.001). In post hoc analysis of the COPE NMP trial, the highest tertile of L-GrAFT₇ was significantly associated with time to liver allograft (hazard ratio [HR] 2.17, p = 0.016), Clavien ≥IIIB (HR 2.60, p = 0.034) and ≥IVa (HR 4.99, p = 0.011) complications; post-LT length of hospitalization (p = 0.002); and renal replacement therapy (odds ratio 3.62, p = 0.016).

CONCLUSIONS

We have validated the L-GrAFT₇ risk score as a generalizable, highly accurate, individualized risk assessment of 3-month liver allograft failure that is superior to existing scores. L-GrAFT₇ may standardize grading of early hepatic allograft function and serve as a clinical endpoint in translational studies (www.lgraft.com).

LAY SUMMARY

Early allograft dysfunction negatively affects outcomes following liver transplantation. In independent multicenter US and European cohorts totaling 3,423 patients undergoing liver transplantation, the liver graft assessment following transplantation (L-GrAFT) risk score is validated as a superior measure of early allograft function that accurately discriminates 3-month graft failure-free survival and post-liver transplantation complications.

New insights into the pathophysiology and clinical care of rare primary liver cancers

Hepatocholangiocarcinoma, fibrolamellar carcinoma, hepatic haemangioendothelioma and hepatic angiosarcoma represent less than 5% of primary liver cancers. Fibrolamellar carcinoma and hepatic haemangioendothelioma are driven by unique somatic genetic alterations (DNAJB1-PRKCA and CAMTA1-WWTR1 fusions, respectively), while the pathogenesis of hepatocholangiocarcinoma remains more complex, as suggested by its histological diversity. Histology is the gold standard for diagnosis, which remains challenging even in an expert centre because of the low incidences of these liver cancers. Resection, when feasible, is the cornerstone of treatment, together with liver transplantation for hepatic haemangioendothelioma. The role of locoregional therapies and systemic treatments remains poorly studied. In this review, we aim to describe the recent advances in terms of diagnosis and clinical management of these rare primary liver cancers.

Progress toward improving outcomes in patients with cholangiocarcinoma

Purpose of review:

To provide an update on latest advances in treatment of cholangiocarcinoma.

Recent findings:

Incidence of cholangiocarcinoma has been increasing over the past decade. A better understanding of the genetic landscape of cholangiocarcinoma and its risk factors resulted in earlier diagnosis and treatment option expansion to targeted therapy with FGFR inhibitors, and liver transplantation for early perihilar cholangiocarcinoma and early intrahepatic cholangiocarcinoma. IDH1/2 inhibition for intrahepatic cholangiocarcinoma is an emerging targeted therapy approach. Data supports benefits of adjuvant therapy for a subset of patients undergoing surgical resection. Approaches combining different treatment modalities such as chemotherapy, surgery, radiation therapy appear promising.

Summary:

Earlier diagnosis and genetic characterization provided additional treatment options for patients with previously incurable cholangiocarcinoma. A precision medicine approach with a focus on actionable genetic alterations and combination of treatment modalities are actively being explored and will further improve outcomes in our patients with cholangiocarcinoma.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.

Liver Transplantation for Colorectal and Neuroendocrine Liver Metastases and Hepatoblastoma. Working Group Report From the ILTS Transplant Oncology Consensus Conference

Liver transplantation (LT) for unresectable colorectal liver metastases has long been abandoned because of dismal prognoses. After the dark ages, advances in chemotherapy and diagnostic imaging have enabled strict patient selection, and the pioneering study from the Oslo group has contributed to the substantial progress in this field. For unresectable neuroendocrine liver metastases, LT for patients who met the Milan criteria was able to achieve excellent long-term outcomes. The guidelines further adopted in the United States and Europe were based on these criteria. For hepatoblastoma, patients with unresectable and borderline-resectable disease are considered good candidates for LT; however, the indications are yet to be defined. In the budding era of transplant oncology, it is critically important to recognize the current status and unsolved questions for each disease entity. These guidelines were developed to serve as a beacon of light for optimal patient selection for LT and set the stage for future basic and clinical studies.

Applicability and results of liver transplant combined with neoadjuvant chemo-radiotherapy in the treatment of unresectable hilar cholangiocarcinoma

BACKGROUND

In 2007, a multicenter protocol was developed in Catalonia, Spain, combining neoadjuvant chemoradiotherapy and liver transplantation (LT) for those patients with unresectable hilar cholangiocarcinoma (hCCA).

AIM

To analyse the effectiveness of the neoadjuvant chemoradiotherapy and LT for those patients enrolled in the protocol based on intention-to-treat.

METHODS

Observational multicenter study which includes patients ≤ 68 years-old diagnosed with unresectable, solitary tumors ≤ 3 cm in radial diameter, without evidence of lymph node metastases. The protocol was based on a strategy of neoadjuvant therapy with high-dose radiation (45 Gy in total) plus intravenous fluorouracil (5-FU) given as a daily bolus for the first 3 days of radiation follow by oral capecitabine until transplantation. The patient was included in waiting list for LT if no evidence of disseminated disease was found.

RESULTS

Between 2007 and 2018, 13 patients were enrolled in the transplant protocol. Of those, 61% (8/13) of the patients were transplanted. The average time spent on the waiting list was 122 days (range 5-192). Intent-to-treat survival was 69% and 39% at one and 5 years. Post-transplantation overall survival was 87% and 62% and 29% recurrence rate at 5 years.

CONCLUSION

The suitability of the neoadjuvant chemoradiotherapy and LT protocol was 61% in our series with long-term overall survival and should be considered as an alternative to resection for patients with localized node-negative hCCA.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure for cholangiocarcinoma

Perihilar cholangiocarcinoma (PHCC) has been a great challenge for surgeons, requiring advanced skills and expertise and was often associated with high morbidity and mortality. Resectability rates are up to 75% even in experienced centers. In patients with PHCC, radical liver and bile duct resection aiming R0 surgical margins offers the best long-term survival. Therefore, extensive resections with low FLR are commonly needed and PVE is offered to induce remnant liver hypertrophy for a long period. Associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) is considered a promising approach inducing rapid remnant hypertrophy to prevent dropouts due to complications or tumor progression and increase resectability. Although poor results were reported initially, refinements in technique and risk adjustment of patient selection improved outcomes. The procedure is still under debate for the indication of PHCC. This article reviews the current literature on ALPPS in treatment of perihilar and intrahepatic cholangiocarcinoma.