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).

Early vs late drain removal after pancreatic resection-a systematic review and meta-analysis.

BACKGROUND: Reducing clinically relevant post-operative pancreatic fistula (CR-POPF) incidence after pancreatic resections has been a topic of great academic interest. Optimizing post-operative drain management is a potential strategy in reducing this major complication. METHODS: Studies involving pancreatic resections, including both pancreaticoduodenectomy (PD) and distal pancreatic resections (DP), with intra-operative drain placement were screened. Early drain removal was defined as removal before or on the 3rd post-operative day (POD) while late drain removal was defined as after the 3rd POD. The primary outcome was CR-POPF, International Study Group of Pancreatic Surgery (ISGPS) Grade B and above. Secondary outcomes were all complications, severe complications, post-operative haemorrhage, intra-abdominal infections, delayed gastric emptying, reoperation, length of stay, readmission, and mortality. RESULTS: Nine studies met the inclusion criteria and were included for analysis. The studies had a total of 8574 patients, comprising 1946 in the early removal group and 6628 in the late removal group. Early drain removal was associated with a significantly lower risk of CR-POPF (OR: 0.24, p < 0.01). Significant reduction in risk of post-operative haemorrhage (OR: 0.55, p < 0.01), intra-abdominal infection (OR: 0.35, p < 0.01), re-admission (OR: 0.63, p < 0.01), re-operation (OR: 0.70, p = 0.03), presence of any complications (OR: 0.46, p < 0.01), and reduced length of stay (SMD: -0.75, p < 0.01) in the early removal group was also observed. CONCLUSION: Early drain removal is associated with significant reductions in incidence of CR-POPF and other post-operative complications. Further prospective randomised trials in this area are recommended to validate these findings.

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.

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.

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.

Comparative study and systematic review of laparoscopic liver resection for hepatocellular carcinoma.

AIM: To compare the surgical outcomes between laparoscopic liver resection (LLR) and open liver resection (OLR) as a curative treatment in patients with hepatocellular carcinoma (HCC). METHODS: A PubMed database search was performed systematically to identify comparative studies of LLR vs OLR for HCC from 2000 to 2014. An extensive text word search was conducted, using combinations of search headings such as "laparoscopy", "hepatectomy", and "hepatocellular carcinoma". A comparative study was also performed in our institution where we analysed surgical outcomes of 152 patients who underwent liver resection between January 2005 to December 2012, of which 42 underwent laparoscopic or hand-assisted laparoscopic resection and 110 underwent open resection. RESULTS: Analysis of our own series and a review of 17 high-quality studies showed that LLR was superior to OLR in terms of short-term outcomes, as patients in the laparoscopic arm were found to have less intraoperative blood loss, less blood transfusions, and a shorter length of hospital stay. In our own series, both LLR and OLR groups were found to have similar overall survival (OS) rates, but disease-free survival (DFS) rates were higher in the laparoscopic arm. CONCLUSION: LLR is associated with better short-term outcomes compared to OLR as a curative treatment for HCC. Long-term oncologic outcomes with regards to OS and DFS rates were found to be comparable in both groups. LLR is hence a safe and viable option for curative resection of HCC.

Laparoscopic drainage of cryptogenic liver abscess.

BACKGROUND: To retrospectively compare the outcomes of percutaneously drained and laparoscopically drained liver abscesses. METHODS: Eight-five consecutive patients with radiological evidence of liver abscess were treated at National University Hospital of Singapore from 2005 to 2011. Multivariable logistic regression was used to identify failures of intervention. This was defined as persistent objective signs of sepsis. Complications, length of antibiotic therapy, and hospital stay were recorded but not used as indicators for failure of intervention. A propensity score analysis was used to adjust for possible confounders. RESULTS: Twenty-seven (40.3%) patients in the percutaneous group did not respond to primary intervention compared to 2 patients (11.1%) in the laparoscopic group (p = 0.020). Two patients within the percutaneous group died from progression of sepsis despite intervention. In the multivariate model with propensity score, laparoscopic drainage had a protective effect against failure compared to percutaneous drainage of liver abscess (odds ratio [OR], 0.03; 95% confidence interval [CI], [0-0.4]; p = 0.008). There were no differences in complications related to the intervention (p = 0.108). Mean duration of antibiotics (p = 0.437) and hospital stay (p = 0.175) between the groups was similar. CONCLUSIONS: Laparoscopic drainage of cryptogenic liver abscesses should be considered as an option for drainage of liver abscess.

Laparoendoscopic single-site minor hepatectomy for liver tumors.

BACKGROUND: Laparoscopic liver surgery is gaining increasing acceptance worldwide, but its frontiers are constantly challenged. Laparoendoscopic single-site surgery (LESS) has been performed for various organs, but the feasibility of LESS hepatectomies has yet to be explored fully. METHODS: From May 2010 to March 2011, seven patients underwent LESS minor hepatectomies. Patient demographic, operative, and clinical data were reviewed. RESULTS: Five left lateral sectionectomies, one segment 3, and one segment 5 resection were performed. The median operative time was 142 min (range, 104-171 min), and the median blood loss was 200 ml (range, 100-450 ml). The median hospital stay was 3 days (range, 1-11 days). For all the patients, the indications for surgery were suspected malignant tumors, and the surgical resection margins were clear for every patient. CONCLUSIONS: Laparoendoscopic single-site minor hepatectomy is a novel modification to traditional laparoscopic surgery. The method is safe and feasible without any compromise to oncologic safety for selected patients with hepatocellular carcinoma (HCC) and colorectal liver metastases that are peripheral and smaller than 5 cm in size.

Single port laparoscopic liver resection for hepatocellular carcinoma: a preliminary report.

Single port laparoscopic surgery is an emerging technique, now commonly used in cholecystectomy. The experience of using this technique in liver resection for hepatocellular carcinoma is described in a series of 3 cases with single port laparoscopic liver resection performed during 2010. All patients were male aged 61 to 70 years, with several comorbidities. There were no complications in this early series. The length of hospital stay was 3-5 days. The blood loss was 200-450 mL, with operating time between 142 and 171 minutes. We conclude that this technique is feasible and safe to perform in experienced centers.

Expanding the donor pool for liver transplantation in the setting of an "opt-out" scheme: 3 years after new legislation.

INTRODUCTION: The revised Human Organ Transplant Act (HOTA) was implemented in Singapore in July 2004. We aim to evaluate expanding the potential donor pool for liver transplant in Singapore with the inclusion of marginal donors. MATERIALS AND METHODS: All donor referrals between July 2004 and June 2007 were studied. All potential deceased liver donors were heart-beating. After being reviewed by the transplant coordinator, potential donors were assessed by a transplant hepatologist and a transplant surgeon for suitability of organ donation strictly based on the programme's donor assessment protocol. Reasons for rejection as potential donors were documented. The clinical characteristics of all donor referrals were retrospectively reviewed, and an independent decision was made as to whether liver retrieval in each rejected case might have been possible. RESULTS: Among the 128 potential donor referrals, 20 donors (15.6%) underwent liver retrieval. Of the 20 livers retrieved, 16 were implanted and 4 were not implanted (3 unfit recipients, and 1 donor liver with 40% steatosis). Another 10 donor livers were assessed intraoperatively and were rejected because of varying levels of steatosis. Of these livers assessed, 5 donor livers had steatosis <40% and 5 had steatosis >40%. Of the remaining potential donors, 45 were deemed not possible because of prolonged hypotension (9), on-going or unresolved sepsis (13), high-risk behaviour (4), non-actualisation (8), or pre-existing medical conditions (11). Another 53 donors may potentially have been suitable donors but were rejected because of possible sepsis (13), no suitable recipients (12), transient hypotension (10), transient abnormal liver function test (6), history of alcohol ingestion (5), non-actualisation because of consent (4) and other reasons (3). Overall, it was deemed that 61 donors (47.7%) might potentially have been suitable liver donors. CONCLUSIONS: Despite new legislation (HOTA) in Singapore, the utilisation of cadaveric donor livers showed no increase in the last 3 years. By expanding our donor criteria to include marginal donors, we could potentially increase the availability of deceased donor livers to meet our waiting list demands.

Acute acalculous cholecystitis: challenging the myths.

BACKGROUND: Acute acalculous cholecystitis (AAC) is traditionally known to occur in critically ill patients, following cardiac surgery, abdominal vascular surgery, severe trauma, burns, prolonged fasting, total parenteral nutrition, or sepsis, and is believed to have a worse prognosis as compared with acute cholecystitis associated with stones. Our observation of de novo presentation of AAC in several outpatients in the absence of critical illness or predisposing factors prompted us to undertake this study. The aims of the present study were to examine the prevalence of AAC patients in the outpatient setting in our hospital, to identify associated risk factors and to assess the clinical course and outcome of these patients. PATIENTS AND METHODS: All patients who had a cholecystectomy (laparoscopic or open surgery) for acute cholecystitis at National University Hospital from January 2001 to May 2005 were reviewed from a prospectively maintained database. The demographic characteristics, clinicopathologic features, operative parameters, postoperative course, and histopathology of the patients were reviewed. RESULTS: Eleven of 133 patients with acute cholecystitis fulfilled the criteria for the diagnosis of AAC. Patients' ages ranged from 30 to 69 years (mean 52.39 years). All these patients presented as outpatients. None of the patients had any critical illness predisposing to AAC. The mean age was slightly less in the AAC group as compared with the remaining patients with acute cholecystitis (52.39 years vs 55.22 years, p=0.54). There was male predominance in the AAC group (male:female = 9:2). The time from admission to surgery, operative procedure, operative time, and postoperative stay were not statistically different from the remaining patients with acute cholecystitis. DISCUSSION: AAC can occur in young and middle-aged healthy individuals, the presentation is no different from acute calculous cholecystitis, the prognosis is good if diagnosed and treated early.

Laparoscopic-assisted management of small bowel obstruction due to phytobezoar.

Laparoscopy is gaining increasing acceptance for diagnosis and treatment of selected cases of small bowel obstruction. We describe a laparoscopic-assisted procedure used for the treatment of small bowel obstruction caused by a bezoar. A 51-year-old man presented with acute small intestinal obstruction. He had no history of previous abdominal surgery. Diagnostic laparoscopy confirmed a distal ileal obstruction due to an enterolith (bezoar). A limited abdominal incision allowed enterotomy and removal of the obstructing bezoar. Gastroscopy performed a month later showed gastric bezoars which could not be removed endoscopically. Instead, cellulase, a hydrolytic enzyme, was used successfully to treat the condition.