A multimodal atlas of hepatocellular carcinoma reveals convergent evolutionary paths and 'bad apple' effect on clinical trajectory.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a highly fatal cancer characterized by high intra-tumor heterogeneity (ITH). A panoramic understanding of its tumor evolution, in relation to its clinical trajectory, may provide novel prognostic and treatment strategies. METHODS: Through the Asia-Pacific Hepatocellular Carcinoma trials group (NCT03267641), we recruited one of the largest prospective cohorts of patients with HCC, with over 600 whole genome and transcriptome samples from 123 treatment-naïve patients. RESULTS: Using a multi-region sampling approach, we revealed seven convergent genetic evolutionary paths governed by the early driver mutations, late copy number variations and viral integrations, which stratify patient clinical trajectories after surgical resection. Furthermore, such evolutionary paths shaped the molecular profiles, leading to distinct transcriptomic subtypes. Most significantly, although we found the coexistence of multiple transcriptomic subtypes within certain tumors, patient prognosis was best predicted by the most aggressive cell fraction of the tumor, rather than by overall degree of transcriptomic ITH level - a phenomenon we termed the 'bad apple' effect. Finally, we found that characteristics throughout early and late tumor evolution provide significant and complementary prognostic power in predicting patient survival. CONCLUSIONS: Taken together, our study generated a comprehensive landscape of evolutionary history for HCC and provides a rich multi-omics resource for understanding tumor heterogeneity and clinical trajectories. IMPACT AND IMPLICATIONS: This prospective study, utilizing comprehensive multi-sector, multi-omics sequencing and clinical data from surgically resected hepatocellular carcinoma (HCC), reveals critical insights into the role of tumor evolution and intra-tumor heterogeneity (ITH) in determining the prognosis of HCC. These findings are invaluable for oncology researchers and clinicians, as they underscore the influence of distinct evolutionary paths and the 'bad apple' effect, where the most aggressive tumor fraction dictates disease progression. These insights not only enhance prognostic accuracy post-surgical resection but also pave the way for personalized treatment strategies tailored to specific tumor evolutionary and transcriptomic profiles. The coexistence of multiple subtypes within the same tumor prompts a re-appraisal of the utilities of depending on single samples to represent the entire tumor and suggests the need for clinical molecular imaging. This research thus marks a significant step forward in the clinical understanding and management of HCC, underscoring the importance of integrating tumor evolutionary dynamics and multi-omics biomarkers into therapeutic decision-making. CLINICAL TRIAL NUMBER: NCT03267641 (Observational cohort).

A genomic enhancer signature associates with hepatocellular carcinoma prognosis.

Background & Aims: Lifestyle and environmental-related exposures are important risk factors for hepatocellular carcinoma (HCC), suggesting that epigenetic dysregulation significantly underpins HCC. We profiled 30 surgically resected tumours and the matched adjacent normal tissues to understand the aberrant epigenetic events associated with HCC. Methods: We identified tumour differential enhancers and the associated genes by analysing H3K27 acetylation (H3K27ac) chromatin immunoprecipitation sequencing (ChIP-seq) and Hi-C/HiChIP data from the resected tumour samples of 30 patients with early-stage HCC. This epigenome dataset was analysed with previously reported genome and transcriptome data of the overlapping group of patients from the same cohort. We performed patient-specific differential expression testing using multiregion sequencing data to identify genes that undergo both enhancer and gene expression changes. Based on the genes selected, we identified two patient groups and performed a recurrence-free survival analysis. Results: We observed large-scale changes in the enhancer distribution between HCC tumours and the adjacent normal samples. Many of the gain-in-tumour enhancers showed corresponding upregulation of the associated genes and vice versa, but much of the enhancer and gene expression changes were patient-specific. A subset of the upregulated genes was activated in a subgroup of patients' tumours. Recurrence-free survival analysis revealed that the patients with a more robust upregulation of those genes showed a worse prognosis. Conclusions: We report the genomic enhancer signature associated with differential prognosis in HCC. Findings that cohere with oncofoetal reprogramming in HCC were underpinned by genome-wide enhancer rewiring. Our results present the epigenetic changes in HCC that offer the rational selection of epigenetic-driven gene targets for therapeutic intervention or disease prognostication in HCC. Impact and Implications: Lifestyle and environmental-related exposures are the important risk factors of hepatocellular carcinoma (HCC), suggesting that tumour-associated epigenetic dysregulations may significantly underpin HCC. We profiled tumour tissues and their matched normal from 30 patients with early-stage HCC to study the dysregulated epigenetic changes associated with HCC. By also analysing the patients' RNA-seq and clinical data, we found the signature genes - with epigenetic and transcriptomic dysregulation - associated with worse prognosis. Our findings suggest that systemic approaches are needed to consider the surrounding cellular environmental and epigenetic changes in HCC tumours.

Multi-region sampling with paired sample sequencing analyses reveals sub-groups of patients with novel patient-specific dysregulation in Hepatocellular Carcinoma.

BACKGROUND: Conventional differential expression (DE) testing compares the grouped mean value of tumour samples to the grouped mean value of the normal samples, and may miss out dysregulated genes in small subgroup of patients. This is especially so for highly heterogeneous cancer like Hepatocellular Carcinoma (HCC). METHODS: Using multi-region sampled RNA-seq data of 90 patients, we performed patient-specific differential expression testing, together with the patients' matched adjacent normal samples. RESULTS: Comparing the results from conventional DE analysis and patient-specific DE analyses, we show that the conventional DE analysis omits some genes due to high inter-individual variability present in both tumour and normal tissues. Dysregulated genes shared in small subgroup of patients were useful in stratifying patients, and presented differential prognosis. We also showed that the target genes of some of the current targeted agents used in HCC exhibited highly individualistic dysregulation pattern, which may explain the poor response rate. DISCUSSION/CONCLUSION: Our results highlight the importance of identifying patient-specific DE genes, with its potential to provide clinically valuable insights into patient subgroups for applications in precision medicine.

Impact of donor age on recipient morbidity and mortality after living donor liver transplantation.

BACKGROUND: Evidence for use of graft from older donors in living donor liver transplantation (LDLT) has been conflicting. This study aims to clarify the impact of donor age on recipient morbidity and mortality after adult LDLT. METHODS: A total of 90 live liver donors and recipients who underwent primary adult-to-adult LDLT were divided into three groups according to donor age: donors in 20s (D-20s) group, donors in 30s and 40s (D-30s and 40s) group and donors in 50s & 60s (D-50s and 60s) group. Multivariate analyses were conducted to look for independent risk/prognostic factors. Donor age was analysed as a continuous variable to determine an optimal cut off. RESULTS: Overall donor morbidity was 4/90 (4.44%), major donor morbidity was 1/90 (1.11%) and there was no donor mortality. Recipients in the D-20s group had better 1-, 3- and 5-year recipient survival than recipients in the D-50s and 60s group (96%, 91%, 91% versus 73%, 58%, 58%, respectively) (P = 0.020). Donor age was identified to be an independently significant risk factor for increased major complications (P = 0.007) and prognostic factor for reduced overall survival (P = 0.014). The optimal donor age cut off was determined to be 46.5 years old. CONCLUSION: Older donors are associated with poorer recipient outcomes after adult-to-adult LDLT. Usage of liver grafts from older donors should be carefully considered when choosing liver grafts for patients undergoing LDLT.

Dynamic phenotypic heterogeneity and the evolution of multiple RNA subtypes in hepatocellular carcinoma: the PLANET study.

Intra-tumor heterogeneity (ITH) is a key challenge in cancer treatment, but previous studies have focused mainly on the genomic alterations without exploring phenotypic (transcriptomic and immune) heterogeneity. Using one of the largest prospective surgical cohorts for hepatocellular carcinoma (HCC) with multi-region sampling, we sequenced whole genomes and paired transcriptomes from 67 HCC patients (331 samples). We found that while genomic ITH was rather constant across stages, phenotypic ITH had a very different trajectory and quickly diversified in stage II patients. Most strikingly, 30% of patients were found to contain more than one transcriptomic subtype within a single tumor. Such phenotypic ITH was found to be much more informative in predicting patient survival than genomic ITH and explains the poor efficacy of single-target systemic therapies in HCC. Taken together, we not only revealed an unprecedentedly dynamic landscape of phenotypic heterogeneity in HCC, but also highlighted the importance of studying phenotypic evolution across cancer types.

Trajectory of immune evasion and cancer progression in hepatocellular carcinoma.

Immune evasion is key to cancer initiation and later at metastasis, but its dynamics at intermediate stages, where potential therapeutic interventions could be applied, is undefined. Here we show, using multi-dimensional analyses of resected tumours, their adjacent non-tumour tissues and peripheral blood, that extensive immune remodelling takes place in patients with stage I to III hepatocellular carcinoma (HCC). We demonstrate the depletion of anti-tumoural immune subsets and accumulation of immunosuppressive or exhausted subsets along with reduced tumour infiltration of CD8 T cells peaking at stage II tumours. Corresponding transcriptomic modification occur in the genes related to antigen presentation, immune responses, and chemotaxis. The progressive immune evasion is validated in a murine model of HCC. Our results show evidence of ongoing tumour-immune co-evolution during HCC progression and offer insights into potential interventions to reverse, prevent or limit the progression of the disease.

Living donor hepatectomy in medium volume liver transplant centre has comparable outcomes to high volume centres: validation of donabedian quality assurance framework.

BACKGROUND: Given the complexity of living donor hepatectomy, it is expected that high hospital volume will better outcomes. This study aims to evaluate post-operative outcomes for living donor hepatectomy in a medium volume liver transplant centre and compare to outcomes in high volume centres. Also, it serves as a validation tool for framework of structure-process-outcome model for safe living donor hepatectomy program. METHODS: 204 donors who underwent donor hepatectomy between June 1996 to September 2019 were reviewed retrospectively and compared to outcomes in high volume centres. RESULTS: At 6 months, overall donor morbidity rate was 20/204 (9.8%). Wound complications were most common at 5/204 (2.5%). Majority of complications were either Clavien grade 1 or 2 and only 3 donors had Clavien grade 3 complications. There was zero donor mortality. DISCUSSION: Our centre's donor morbidity rate of 9.8% is the one of the lowest reported in the published literature. With increased experience, stringent donor selection and enhanced perioperative care by a multi-disciplinary team, outcomes in a medium volume centre can match the outcomes reported in high volume centres. The framework for quality in terms of structure, process and outcomes is presented which can be adopted for developing programs.

Evaluation of Adult Living Donor Liver Transplantation in Largest Southeast Asian Transplantation Center: Benchmarking With Adult-to-Adult Living Donor Liver Transplantation (A2ALL) Experience.

BACKGROUND: The volume-outcome relation for complex surgical procedures such as living donor liver transplantation (LDLT) generally favors high volume (HV) centers. It is important for low to medium volume (MV) centers to evaluate their centers' performance against HV centers to allow early detection and correction of potential systemic issues. There is a dearth of national and international comprehensive registries for LDLT that may allow reasonable risk-adjusted comparisons for benchmarking. This study aims to evaluate the LDLT program by comparing our center's performance against HV centers of the Adult-to-Adult Living Donor Liver Transplantation cohort. STUDY DESIGN: Patient outcomes from a MV transplant center were compared with 11 HV transplant centers from the Adult-to-Adult Living Donor Liver Transplantation cohort. Outcomes evaluated included length of hospital stay, same admission mortality, 90-day mortality, and overall survival. RESULTS: A total of 1381 patients were analzyed. HV 1 to 4, 6, 8, 9, and 11 centers had a shorter median length of hospital stay compared with the MV center (All Dunnett corrected P values all less than .05). HV 9 and 11 centers had lower same admission mortality compared with the MV center (Dunnett corrected P = .023 and .015). After adjusting for other significant predictors, the MV center had comparable 90-day mortality rates and overall survival rates to all HV centers. CONCLUSION: This benchmarking exercise has demonstrated that the limitation of low institutional case volume can be overcome with a protocol-based framework to implement a safe LDLT program. This framework presented can be adopted for developing programs.

Gut microbiome in acute pancreatitis: A review based on current literature.

The gut microbiome is a complex microbial community, recognized for its potential role in physiology, health, and disease. The available evidence supports the role of gut dysbiosis in pancreatic disorders, including acute pancreatitis (AP). In AP, the presence of gut barrier damage resulting in increased mucosal permeability may lead to translocation of intestinal bacteria, necrosis of pancreatic and peripancreatic tissue, and infection, often accompanied by multiple organ dysfunction syndrome. Preserving gut microbial homeostasis may reduce the systemic effects of AP. A growing body of evidence suggests the possible involvement of the gut microbiome in various pancreatic diseases, including AP. This review discusses the possible role of the gut microbiome in AP. It highlights AP treatment and supplementation with prebiotics, synbiotics, and probiotics to maintain gastrointestinal microbial balance and effectively reduce hospitalization, morbidity and mortality in an early phase. It also addresses novel therapeutic areas in the gut microbiome, personalized treatment, and provides a roadmap of human microbial contributions to AP that have potential clinical benefit.

Presence of tumor cells in intra-operative blood salvage autotransfusion samples from hepatocellular carcinoma liver transplantation: analysis using highly sensitive microfluidics technology.

BACKGROUND: The application of intra-operative blood salvage autotransfusion(IBSA) in liver transplantation(LT) for hepatocellular carcinoma(HCC) remains controversial due to the theoretical risk of tumour cell(TC) reintroduction. Current studies evaluating for presence of TC are limited by suboptimal detection techniques. This study aims to analyze the presence of TC in HCC LT autologous blood using microfluidics technology. METHODS: A prospective study of HCC patients who underwent LT from February 2018-April 2019 was conducted. Blood samples were collected peri-operatively. TCs were isolated using microfluidics technology and stained with antibody cocktails for confirmation. RESULTS: A total of 15 HCC LT patients were recruited. All recipients had tumour characteristics within the University of California, San Francisco(UCSF) criteria pre-operatively. TC was detected in all of the autologous blood samples collected from the surgical field. After IOCS wash, five patients had no detectable TC, while 10 patients had detectable TC; of these two remained positive for TC after Leukocyte Depletion Filter(LDF) filtration. CONCLUSION: The risk of tumour cell reintroduction using IBSA in HCC LT patients can be reduced with a single LDF. Future studies should evaluate the proliferation capacity and tumorigenicity of HCC TC in IBSA samples, and the effects of TC reintroduction in patients with pre-existing HCC TCs.

Multi-Phase Cross-modal Learning for Noninvasive Gene Mutation Prediction in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and the fourth most common cause of cancer-related death worldwide. Understanding the underlying gene mutations in HCC provides great prognostic value for treatment planning and targeted therapy. Radiogenomics has revealed an association between non-invasive imaging features and molecular genomics. However, imaging feature identification is laborious and error-prone. In this paper, we propose an end-to-end deep learning framework for mutation prediction in APOB, COL11A1 and ATRX genes using multiphasic CT scans. Considering intra-tumour heterogeneity (ITH) in HCC, multi-region sampling technology is implemented to generate the dataset for experiments. Experimental results demonstrate the effectiveness of the proposed model.

An international multicenter study of protocols for liver transplantation during a pandemic: A case for quadripartite equipoise.

BACKGROUND & AIMS: The outbreak of COVID-19 has vastly increased the operational burden on healthcare systems worldwide. For patients with end-stage liver failure, liver transplantation is the only option. However, the strain on intensive care facilities caused by the pandemic is a major concern. There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources. METHODS: We performed an international multicenter study of transplant centers to understand the evolution of policies for transplant prioritization in response to the pandemic in March 2020. To describe the ethical tension arising in this setting, we propose a novel ethical framework, the quadripartite equipoise (QE) score, that is applicable to liver transplantation in the context of limited national resources. RESULTS: Seventeen large- and medium-sized liver transplant centers from 12 countries across 4 continents participated. Ten centers opted to limit transplant activity in response to the pandemic, favoring a "sickest-first" approach. Conversely, some larger centers opted to continue routine transplant activity in order to balance waiting list mortality. To model these and other ethical tensions, we computed a QE score using 4 factors - recipient outcome, donor/graft safety, waiting list mortality and healthcare resources - for 7 countries. The fluctuation of the QE score over time accurately reflects the dynamic changes in the ethical tensions surrounding transplant activity in a pandemic. CONCLUSIONS: This four-dimensional model of quadripartite equipoise addresses the ethical tensions in the current pandemic. It serves as a universally applicable framework to guide regulation of transplant activity in response to the increasing burden on healthcare systems. LAY SUMMARY: There is an urgent need for ethical frameworks to balance the need for liver transplantation against the availability of national resources during the COVID-19 pandemic. We describe a four-dimensional model of quadripartite equipoise that models these ethical tensions and can guide the regulation of transplant activity in response to the increasing burden on healthcare systems.

Clinical management and outcomes of acute pancreatitis: Identifying areas for quality improvement in a tertiary Asian setting.

BACKGROUND: This study aims to review the clinical management of patients with acute pancreatitis in a tertiary institute in Singapore, and to identify areas qualiy improvement based on validation against the recommendations in the IAP/APA and the Japanese guidelines. METHODS: 391 patients from a prospective electronic database were included and reviewed for compliance to the International Association of Pancreatology (IAP)/American Pancreatic Association (APA) guidelines (2013) and the Japanase Guidelines (2015). RESULTS: The 90 day mortality was 8.4% for moderately severe and 11.9% for severe pancreatitis. The accuracy of SIRS in predicting severe acute pancreatitis on admission was 72.1% and at 48 h 80.8%. Only 61.1% patients had ultrasound scan during their admission of whom 32.9% had it within 24 h of admission. 18.3% patients with initial diagnosis of idiopathic pancreatitis had EUS. 50% received Ringer lactate for initial fluid resuscitation. 38.7% received antibiotics as prophylaxis. 21.4% with severe acute pancreatitis had early enteral nutrition. Only 21.4% patients with biliary pancreatitis had index admission cholecystectomy. CONCLUSION: The compliance to existing guidelines for management of acute pancreatitis is variable. Identifying gaps and implementing measures to address them allows for continued improvement in the management of patients with acute pancreatitis.

Propensity score-matched analysis of early outcomes after laparoscopic-assisted versus open pancreaticoduodenectomy.

BACKGROUND: Minimally invasive pancreaticoduodenectomy (PD) is a feasible option for periampullary tumours. However, it remains a complex procedure with no proven advantages over open PD (OPD). The aim of the study was to compare the outcomes between laparoscopic-assisted PD (LAPD) and OPD using a propensity score-matched analysis. METHODS: Retrospective review of 40 patients who underwent PD for periampullary tumours between January 2014 and December 2016 was conducted. The patients were matched 1:1 for age, gender, body mass index, Charlson comorbidty index, tumour size and haematological indices. Peri-operative outcomes were evaluated. RESULTS: LAPD appeared to have a longer median operative time as compared to OPD (LAPD, 425 min (285-597) versus OPD, 369 min (260-500)) (P = 0.066). Intra-operative blood loss was comparable between both groups. Respiratory complications were five times higher in the OPD group (LAPD, 5% versus OPD, 25%) (P = 0.077), while LAPD patients required less time to start ambulating post-operatively (LAPD, 2 days versus OPD, 2 days) (P = 0.021). Pancreas-specific complications and morbidity/mortality rates were similar. CONCLUSION: LAPD is a safe alternative to OPD in a select group of patients for an institution starting out with minimally invasive PD, and can be used to bridge the learning curve required for total laparoscopic PD.

The influence of the middle hepatic vein and its impact on outcomes in right lobe living donor liver transplantation.

BACKGROUND: In adult right lobe living donor liver transplantation, the decision to include the middle hepatic vein (MHV) remains controversial. METHODS: A retrospective analysis of 50 R-LDLTs between January 2008 and June 2016 was performed. RESULTS: Twenty-one procedures were performed using a MHV+ graft (42.0%) and 29 procedures using a MHV- graft (58%). MHV- donors were taller (173 vs 166 cm, p = 0.004) with a larger standard liver volume (1351 vs 1245 mls, p = 0.014) compared to MHV+ donors. The duration of operation for donors was significantly longer in the MHV+ group (530 (313-975) mins) compared to the MHV- group (489 (336-708) mins) (p = 0.029). Similarly, the operative time for recipients was longer in the MHV+ group (660 (428-831) mins) compared to MHV- (579 (359-1214) mins) (p = 0.023). MHV- grafts were heavier compared to MHV+ grafts (918 vs 711 g, p = 0.017). Recipient mortality rates and Kaplan-Meier survival analysis were comparable (p = 0.411). All donors were well at last review. CONCLUSION: Both MHV+ and MHV- grafts are safe for the donor and recipient. The decision to take the MHV should be based on specific donor-recipient characteristics.

Bridging therapies to liver transplantation for hepatocellular carcinoma: A bridge to nowhere?

BACKGROUNDS/AIMS: Liver Transplantation (LT) is a recognized treatment for Hepatocellular Carcinoma (HCC). The role of Bridging Therapies (BT) remains controversial. METHODS: From January 2001 to October 2012, 192 patients were referred to the National University Hospital, Singapore for consideration of LT for HCC. Sixty-five patients (33.8%) were found suitable for transplant and were placed on the waitlist. Analysis was performed in these patients. RESULTS: The most common etiology of HCC was Hepatitis B (n=28, 43.1%). Thirty-six patients (55.4%) received BT. Seventeen patients (47.2%) received TACE only, while 10 patients (27.8%) received radiofrequency ablation (RFA) only. The remaining patients received a combination of transarterial chemoembolization (TACE) and RFA. Baseline tumor and patient characteristics were comparable between the two groups. The overall dropout rate was 44.4% and 31.0% in the BT and non-BT groups, respectively (p=0.269). The dropout rate due to disease progression beyond criteria was 6.9% (n=2) in the non-bridged group and 22.2% (n=8) in the bridged group (p=0.089). Thirty-nine patients (60%) underwent LT, of which all patients who underwent Living Donor LT did not receive BT (n=4, 21.1%, p=0.030). The median time to LT was 180 days (range, 20-558 days) in the non-BT group and 291 days (range, 17-844 days) in the BT group (p=0.214). There was no difference in survival or recurrence between the BT and non-BT groups (p=0.862). CONCLUSIONS: BT does not influence the dropout rate or survival after LT but it should be considered in patients who are on the waitlist for more than 6 months.