Onco-fetal Reprogramming of Endothelial Cells Drives Immunosuppressive Macrophages in Hepatocellular Carcinoma.

We employed scRNA sequencing to extensively characterize the cellular landscape of human liver from development to disease. Analysis of ∼212,000 cells representing human fetal, hepatocellular carcinoma (HCC), and mouse liver revealed remarkable fetal-like reprogramming of the tumor microenvironment. Specifically, the HCC ecosystem displayed features reminiscent of fetal development, including re-emergence of fetal-associated endothelial cells (PLVAP/VEGFR2) and fetal-like (FOLR2) tumor-associated macrophages. In a cross-species comparative analysis, we discovered remarkable similarity between mouse embryonic, fetal-liver, and tumor macrophages. Spatial transcriptomics further revealed a shared onco-fetal ecosystem between fetal liver and HCC. Furthermore, gene regulatory analysis, spatial transcriptomics, and in vitro functional assays implicated VEGF and NOTCH signaling in maintaining onco-fetal ecosystem. Taken together, we report a shared immunosuppressive onco-fetal ecosystem in fetal liver and HCC. Our results unravel a previously unexplored onco-fetal reprogramming of the tumor ecosystem, provide novel targets for therapeutic interventions in HCC, and open avenues for identifying similar paradigms in other cancers and disease.

Non-terminally exhausted tumor-resident memory HBV-specific T cell responses correlate with relapse-free survival in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) often develops following chronic hepatitis B virus (HBV) infection and responds poorly to immune checkpoint blockade. Here, we examined the antigen specificities of HCC-infiltrating T cells and their relevance to tumor control. Using highly multiplexed peptide-MHC tetramer staining of unexpanded cells from blood, liver, and tumor tissues from 46 HCC patients, we detected 91 different antigen-specific CD8+ T cell populations targeting HBV, neoantigen, tumor-associated, and disease-unrelated antigens. Parallel high-dimensional analysis delineated five distinct antigen-specific tissue-resident memory T (Trm) cell populations. Intratumoral and intrahepatic HBV-specific T cells were enriched for two Trm cell subsets that were PD-1loTOXlo, despite being clonally expanded. High frequencies of intratumoral terminally exhausted T cells were uncommon. Patients with tumor-infiltrating HBV-specific CD8+ Trm cells exhibited longer-term relapse-free survival. Thus, non-terminally exhausted HBV-specific CD8+ Trm cells show hallmarks of active involvement and effective antitumor response, implying that these cells could be harnessed for therapeutic purposes.

The association between tumour heterogeneity and immune evasion mechanisms in hepatocellular carcinoma and its clinical implications.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. The emergence of combination therapy, atezolizumab (anti-PDL1, immune checkpoint inhibitor) and bevacizumab (anti-VEGF) has revolutionised the management of HCC. Despite this breakthrough, the best overall response rate with first-line systemic therapy is only about 30%, owing to intra-tumoural heterogeneity, complex tumour microenvironment and the lack of predictive biomarkers. Many groups have attempted to classify HCC based on the immune microenvironment and have consistently observed better outcomes in immunologically "hot" HCC. We summarised possible mechanisms of tumour immune evasion based on the latest literature and the rationale for combination/sequential therapy to improve treatment response. Lastly, we proposed future strategies and therapies to overcome HCC immune evasion to further improve treatment outcomes of HCC.

Atezolizumab plus bevacizumab versus active surveillance in patients with resected or ablated high-risk hepatocellular carcinoma (IMbrave050): a randomised, open-label, multicentre, phase 3 trial.

BACKGROUND: No adjuvant treatment has been established for patients who remain at high risk for hepatocellular carcinoma recurrence after curative-intent resection or ablation. We aimed to assess the efficacy of adjuvant atezolizumab plus bevacizumab versus active surveillance in patients with high-risk hepatocellular carcinoma. METHODS: In the global, open-label, phase 3 IMbrave050 study, adult patients with high-risk surgically resected or ablated hepatocellular carcinoma were recruited from 134 hospitals and medical centres in 26 countries in four WHO regions (European region, region of the Americas, South-East Asia region, and Western Pacific region). Patients were randomly assigned in a 1:1 ratio via an interactive voice-web response system using permuted blocks, using a block size of 4, to receive intravenous 1200 mg atezolizumab plus 15 mg/kg bevacizumab every 3 weeks for 17 cycles (12 months) or to active surveillance. The primary endpoint was recurrence-free survival by independent review facility assessment in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT04102098. FINDINGS: The intention-to-treat population included 668 patients randomly assigned between Dec 31, 2019, and Nov 25, 2021, to either atezolizumab plus bevacizumab (n=334) or to active surveillance (n=334). At the prespecified interim analysis (Oct 21, 2022), median duration of follow-up was 17·4 months (IQR 13·9-22·1). Adjuvant atezolizumab plus bevacizumab was associated with significantly improved recurrence-free survival (median, not evaluable [NE]; [95% CI 22·1-NE]) compared with active surveillance (median, NE [21·4-NE]; hazard ratio, 0·72 [adjusted 95% CI 0·53-0·98]; p=0·012). Grade 3 or 4 adverse events occurred in 136 (41%) of 332 patients who received atezolizumab plus bevacizumab and 44 (13%) of 330 patients in the active surveillance group. Grade 5 adverse events occurred in six patients (2%, two of which were treatment related) in the atezolizumab plus bevacizumab group, and one patient (<1%) in the active surveillance group. Both atezolizumab and bevacizumab were discontinued because of adverse events in 29 patients (9%) who received atezolizumab plus bevacizumab. INTERPRETATION: Among patients at high risk of hepatocellular carcinoma recurrence following curative-intent resection or ablation, recurrence-free survival was improved in those who received atezolizumab plus bevacizumab versus active surveillance. To our knowledge, IMbrave050 is the first phase 3 study of adjuvant treatment for hepatocellular carcinoma to report positive results. However, longer follow-up for both recurrence-free and overall survival is needed to assess the benefit-risk profile more fully. FUNDING: F Hoffmann-La Roche/Genentech.

The altered lipidome of hepatocellular carcinoma.

Alterations in metabolic pathways are a hallmark of cancer. A deeper understanding of the contribution of different metabolites to carcinogenesis is thus vitally important to elucidate mechanisms of tumor initiation and progression to inform therapeutic strategies. Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide and its altered metabolic landscape is beginning to unfold with the advancement of technologies. In particular, characterization of the lipidome of human HCCs has accelerated, and together with biochemical analyses, are revealing recurrent patterns of alterations in glycerophospholipid, sphingolipid, cholesterol and bile acid metabolism. These widespread alterations encompass a myriad of lipid species with numerous roles affecting multiple hallmarks of cancer, including aberrant growth signaling, metastasis, evasion of cell death and immunosuppression. In this review, we summarize the current trends and findings of the altered lipidomic landscape of HCC and discuss their potential biological significance for hepatocarcinogenesis.

Hypoxia-driven immunosuppression by Treg and type-2 conventional dendritic cells in HCC.

BACKGROUND AND AIMS: Hypoxia is one of the central players in shaping the immune context of the tumor microenvironment (TME). However, the complex interplay between immune cell infiltrates within the hypoxic TME of HCC remains to be elucidated. APPROACH AND RESULTS: We analyzed the immune landscapes of hypoxia-low and hypoxia-high tumor regions using cytometry by time of light, immunohistochemistry, and transcriptomic analyses. The mechanisms of immunosuppression in immune subsets of interest were further explored using in vitro hypoxia assays. Regulatory T cells (Tregs) and a number of immunosuppressive myeloid subsets, including M2 macrophages and human leukocyte antigen-DR isotype (HLA-DRlo ) type 2 conventional dendritic cell (cDC2), were found to be significantly enriched in hypoxia-high tumor regions. On the other hand, the abundance of active granzyme Bhi PD-1lo CD8+ T cells in hypoxia-low tumor regions implied a relatively active immune landscape compared with hypoxia-high regions. The up-regulation of cancer-associated genes in the tumor tissues and immunosuppressive genes in the tumor-infiltrating leukocytes supported a highly pro-tumorigenic network in hypoxic HCC. Chemokine genes such as CCL20 (C-C motif chemokine ligand 20) and CXCL5 (C-X-C motif chemokine ligand 5) were associated with recruitment of both Tregs and HLA-DRlo cDC2 to hypoxia-high microenvironments. The interaction between Tregs and cDC2 under a hypoxic TME resulted in a loss of antigen-presenting HLA-DR on cDC2. CONCLUSIONS: We uncovered the unique immunosuppressive landscapes and identified key immune subsets enriched in hypoxic HCC. In particular, we identified a potential Treg-mediated immunosuppression through interaction with a cDC2 subset in HCC that could be exploited for immunotherapies.

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.

Intraoperative blood transfusion does not impact overall and recurrence-free survival after curative hepatectomy for hepatocellular carcinoma: A propensity-score-matched and inverse probability of treatment-weighted study.

INTRODUCTION: Our primary objective was to determine if receiving intraoperative blood transfusion was a significant prognostic factor for overall and recurrence-free survival after curative resection of hepatic cellular carcinoma (HCC). METHODOLOGY: Between 2001 and 2018, 1092 patients with histologically proven primary HCC who underwent curative liver resection were retrospectively reviewed. Primary study endpoints were recurrence-free survival (RFS) and overall survival (OS). The main analysis was undertaken using propensity-score matching (PSM) to minimize confounding and selection biases in the comparison of patients with or without transfusion. RESULTS: There were 220 patients who received and 666 patients who did not receive intraoperative blood transfusion. The PSM cohort consisted of 163 pairs of patients. After PSM, the only perioperative outcome that appeared to significantly affect whether patients would receive blood transfusion was median blood loss (p = 0.001). In the PSM cohort, whether patients received blood transfusion was neither associated with OS (p = 0.759) nor RFS (p = 0.830). When the volume of blood transfusion was analyzed as a continuous variable, no significant dose-response relationship between blood transfusion volume and HR for OS and RFS was noted. CONCLUSION: Intraoperative blood transfusion had no significant impact on the survival outcomes in patients who receive curative resection in primary HCC.

Lgr5+ pericentral hepatocytes are self-maintained in normal liver regeneration and susceptible to hepatocarcinogenesis.

Emerging evidence suggests that hepatocytes are primarily maintained by self-renewal during normal liver homeostasis, as well as in response to a wide variety of hepatic injuries. However, how hepatocytes in distinct anatomic locations within the liver lobule are replenished under homeostasis and injury-induced regeneration remains elusive. Using a newly developed bacterial artificial chromosome (BAC)-transgenic mouse model, we demonstrate that Lgr5 expression in the liver is restricted to a unique subset of hepatocytes most adjacent to the central veins. Genetic lineage tracing revealed that pericentral Lgr5+ hepatocytes have a long lifespan and mainly contribute to their own lineage maintenance during postnatal liver development and homeostasis. Remarkably, these hepatocytes also fuel the regeneration of their own lineage during the massive and rapid regeneration process following two-thirds partial hepatectomy. Moreover, Lgr5+ hepatocytes are found to be the main cellular origin of diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) and are highly susceptible to neoplastic transformation triggered by activation of Erbb pathway. Our findings establish an unexpected self-maintaining mode for a defined subset of hepatocytes during liver homeostasis and regeneration, and identify Lgr5+ pericentral hepatocytes as major cells of origin in HCC development.

Comparison between short and long-term outcomes after minimally invasive versus open primary liver resections for hepatocellular carcinoma: A 1:1 matched analysis.

BACKGROUND: This study aims to compare the short- and long-term outcomes of patients undergoing minimally invasive liver resection (MILR) versus open liver resection (OLR) for nonrecurrent hepatocellular carcinoma (HCC). METHODS: Review of 204 MILR and 755 OLR without previous LR performed between 2005 and 2018. 1:1 coarsened exact matching (CEM) and 1:1 propensity-score matching (PSM) were performed. RESULTS: Overall, 190 MILR were well-matched with 190 OLR by PSM and 86 MILR with 86 OLR by CEM according to patient baseline characteristics. After PSM and CEM, MILR was associated with a significantly longer operation time [230 min (interquartile range [IQR], 145-330) vs. 160 min (IQR, 125-210), p < .001] [215 min (IQR, 135-295) vs. 153.5 min (120-180), p < .001], shorter postoperative stay [4 days (IQR, 3-6) vs. 6 days (IQR, 5-8), p = .001)] [4 days (IQR, 3-5) vs. 6 days (IQR, 5-7), p = .004] and lower postoperative morbidity [40 (21%) vs. 67 (35.5%), p = .003] [16 (18.6%) vs. 27 (31.4%), p = .036] compared to OLR. MILR was also associated with a significantly longer median time to recurrence (70 vs. 40.3 months, p = .014) compared to OLR after PSM but not CEM. There was no significant difference in terms of overall survival and recurrence-free survival. CONCLUSION: MILR is associated with superior short-term postoperative outcomes and with at least equivalent long-term oncological outcomes compared to OLR for HCC.

Actual 10-year survivors and 10-year recurrence free survivors after primary liver resection for hepatocellular carcinoma in the 21st century: A single institution contemporary experience.

BACKGROUND: At present, the majority of outcome studies of survival of hepatocellular carcinoma (HCC) post-liver resection (post-LR) present actuarial survival data, which often results in overestimation of survival. We sought to evaluate the actual 10-year survival post-LR for HCC and identify variables that are associated with long-term survival. METHODS: We performed a retrospective review of 600 consecutive patients who underwent primary LR for HCC from 2000 to 2010 at our institution. Twenty-eight patients (4.7%) with 90-day mortality and 125 patients who were lost to follow-up within 10 years were excluded leaving 447 patients who met the study criteria. RESULTS: There were 140 actual 10-year survivors of which 57 (40.7%) had a recurrence within 10 years. The actual 10-year overall survival (OS) rate of the 447 patients was 31.5% and the actual 10-year recurrence-free survival (RFS) was 18.6%. Multivariate analyses demonstrated that only age >65 years (OR, 0.29; p < .001) (OR, 0.973; p = .041) and presence of cirrhosis (OR. 0.37; p = .005) (OR, 0.31; p = .001) were independent factors negatively associated with actual 10-year OS and actual 10-year RFS, respectively. CONCLUSION: Approximately one-third of patients will survive over 10 years after LR for HCC. Amongst these 10-year survivors, 41% had developed recurrent cancer within 10-years of follow-up.

Preoperative Predictors of Futile Resection of Intraabdominal Extrahepatic Metastases from Hepatocellular Carcinoma.

BACKGROUND: The management of post-liver resection recurrence is often the life-limiting factor in HCC treatment. While much has been published on intrahepatic recurrence and lung metastasis, there is a relative lack of data on intraabdominal extrahepatic metastasis (EHM). We sought to evaluate the outcomes of patients post-resection of intraabdominal EHM and assess preoperative factors predictive of early recurrence post-metastasectomy. METHODS: We performed a retrospective review of 25 consecutive patients who underwent metastasectomy for intraabdominal EHM from 2003 to 2016 at our institution. RESULTS: Of the 25 cases of EHM, 16 were in the peritoneum, 3 in the adrenal glands, 3 in the large bowel, 1 in the spleen, 1 in the pancreas and 1 in the omentum. Median overall survival was 27 months (IQR 15-89 months). Twenty-one patients (84%) developed recurrence post-metastasectomy of EHM of which 12 patients experienced early recurrence within 12 months. The median time to recurrence post-metastasectomy was 11(IQR 15.5) months. Multivariate analysis demonstrated both hepatitis B (11 (91.6%) versus 4 (44.4%), p = 0.00) status and high tumour grade (8 (66.6%) versus 3 (25%), p = 0.004) to be significant independent predictors of early recurrence. Patients who experienced early recurrence had a significantly shorter median overall survival (18 months (95% CI 12.9-23.0)) compared to those who did not (89 months (95% CI 24.8-153.1), p = 0.004). CONCLUSION: Patients with EHM who underwent metastasectomy had a median overall survival of 27 months. Hepatitis B positivity and high primary tumour grade were preoperative predictors of futile surgery. All 7 patients who had both hepatitis B and high tumour grade experienced early recurrence post-metastasectomy.

Changing trends in the clinicopathological features, practices and outcomes in the surgical management for cystic lesions of the pancreas and impact of the international guidelines: Single institution experience with 462 cases between 1995-2018.

INTRODUCTION: The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice. METHODS: 462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998-2006, 2007-2012 and 2013 to 2018. RESULTS: Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HRSG06 and HRFG12 CLP with a corresponding lower proportion of LRSG06 and LRFG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated. CONCLUSIONS: Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HRSG06 and HRFG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

Pre-operative Imaging Characteristics in Histology-Proven Resected Intrahepatic Cholangiocarcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver cancers. With the increasing incidence of ICC over the past two decades in Asia, it is essential to differentiate between HCC and ICC. However, ICC may mimic the radiological appearance of HCC on computed tomography scans (CT) and magnetic resonance imaging (MRI), leading to misdiagnosis of ICC. The objective of this study is to evaluate and describe the association of specific pre-operative imaging characteristics (arterial enhancement, portal venous washout) in patients with histologically proven resected ICC in our centre. METHODS: Data on patients with histology-proven ICC and mixed hepatocellular-cholangiocarcinomas (HCC-CC) who had undergone surgical resection at Singapore General Hospital (SGH) were identified from a prospectively maintained database. Pre-operative cross-sectional imaging reports were analysed. RESULTS: Ninety-one patients underwent resection between 1 January 2000 and 31 December 2016. Among those with no risk factors for HCC, a significant percentage of patients with ICC (24.3%) show imaging characteristics of both arterial phase hyperenhancement and non-peripheral venous washout. Among patients with risk factors for HCC, between 20.0 and 33.3% of patients with pure ICC fulfilled the imaging criteria for HCC, and this proportion was generally even higher in the mixed HCC-CC group. CONCLUSIONS: A significant proportion of patients with pure ICC showed pre-operative imaging characteristics which fulfilled the diagnostic criteria for HCC. The differential of ICC should be borne in mind in populations where both malignancies are endemic.

Minimally Invasive Versus Open Pancreatectomies for Pancreatic Neuroendocrine Neoplasms: A Propensity-Score-Matched Study.

BACKGROUND: Pancreatic neuroendocrine neoplasms (PNENs) are increasingly prevalent with modern imaging, and surgical excision remains mainstay of treatment. This study aims to perform a propensity-score-matched (PSM) comparison of perioperative and oncologic outcomes following minimally invasive pancreatectomy (MIP) versus open pancreatectomy (OP) for PNEN. METHODS: A retrospective review was performed on patients who underwent curative-intent surgery for PNEN at Singapore General Hospital from 1997 to 2018. A 1:1 PSM was performed between MIP and OP, after which both groups were balanced for baseline variables. RESULTS: We studied 134 patients who underwent surgery (36 MIP and 98 OP) for PNEN. Propensity-score-matched comparison between 35 MIP and 35 OP patients revealed that the MIP group had a longer operating time (MD = 75.0, 95% CI 15.2 to 134.8, P = 0.015), lower intraoperative blood loss (MD = - 400.0, 95% CI - 630.5 to - 169.5, P = 0.001), shorter median postoperative stay (MD = - 1.0, 95% CI - 1.9 to - 0.1, P = 0.029) and shorter median time to diet (MD = - 1.0, 95% CI - 1.9 to - 0.1, P = 0.039). There were no differences between both groups for short-term adverse outcomes and oncologic clearance. Overall survival (HR = 0.84, 95% CI 0.28 to 2.51, P = 0.761) and disease-free survival (HR = 0.57, 95% CI 0.20 to 1.64, P = 0.296) were comparable. CONCLUSION: MIP is a safe and feasible approach for PNEN and is associated with a lower intraoperative blood loss, decreased postoperative stay and time to oral intake, at the expense of a longer operative time compared to OP.

Delineation of an immunosuppressive gradient in hepatocellular carcinoma using high-dimensional proteomic and transcriptomic analyses.

The recent development of immunotherapy as a cancer treatment has proved effective over recent years, but the precise dynamics between the tumor microenvironment (TME), nontumor microenvironment (NTME), and the systemic immune system remain elusive. Here, we interrogated these compartments in hepatocellular carcinoma (HCC) using high-dimensional proteomic and transcriptomic analyses. By time-of-flight mass cytometry, we found that the TME was enriched in regulatory T cells (Tregs), tissue resident memory CD8+ T cells (TRMs), resident natural killer cells (NKRs), and tumor-associated macrophages (TAMs). This finding was also validated with immunofluorescence staining on Foxp3+CD4+ and PD-1+CD8+ T cells. Interestingly, Tregs and TRMs isolated from the TME expressed multiple markers for T-cell exhaustion, including PD-1, Lag-3, and Tim-3 compared with Tregs and TRMs isolated from the NTME. We found PD-1+ TRMs were the predominant T-cell subset responsive to anti-PD-1 treatment and significantly reduced in number with increasing HCC tumor progression. Furthermore, T-bet was identified as a key transcription factor, negatively correlated with PD-1 expression on memory CD8+ T cells, and the PD-1:T-bet ratio increased upon exposure to tumor antigens. Finally, transcriptomic analysis of tumor and adjacent nontumor tissues identified a chemotactic gradient for recruitment of TAMs and NKRs via CXCR3/CXCL10 and CCR6/CCL20 pathways, respectively. Taken together, these data confirm the existence of an immunosuppressive gradient across the TME, NTME, and peripheral blood in primary HCC that manipulates the activation status of tumor-infiltrating leukocytes and renders them immunocompromised against tumor cells. By understanding the immunologic composition of this gradient, more effective immunotherapeutics for HCC may be designed.

Immune activation underlies a sustained clinical response to Yttrium-90 radioembolisation in hepatocellular carcinoma.

OBJECTIVES: Yttrium-90 (Y90)-radioembolisation (RE) significantly regresses locally advanced hepatocellular carcinoma and delays disease progression. The current study is designed to deeply interrogate the immunological impact of Y90-RE, which elicits a sustained therapeutic response. DESIGN: Time-of-flight mass cytometry and next-generation sequencing (NGS) were used to analyse the immune landscapes of tumour-infiltrating leucocytes (TILs), tumour tissues and peripheral blood mononuclear cells (PBMCs) at different time points before and after Y90-RE. RESULTS: TILs isolated after Y90-RE exhibited signs of local immune activation: higher expression of granzyme B (GB) and infiltration of CD8+ T cells, CD56+ NK cells and CD8+ CD56+ NKT cells. NGS confirmed the upregulation of genes involved in innate and adaptive immune activation in Y90-RE-treated tumours. Chemotactic pathways involving CCL5 and CXCL16 correlated with the recruitment of activated GB+CD8+ T cells to the Y90-RE-treated tumours. When comparing PBMCs before and after Y90-RE, we observed an increase in tumour necrosis factor-α on both the CD8+ and CD4+ T cells as well as an increase in percentage of antigen-presenting cells after Y90-RE, implying a systemic immune activation. Interestingly, a high percentage of PD-1+/Tim-3+CD8+ T cells coexpressing the homing receptors CCR5 and CXCR6 denoted Y90-RE responders. A prediction model was also built to identify sustained responders to Y90-RE based on the immune profiles from pretreatment PBMCs. CONCLUSION: High-dimensional analysis of tumour and systemic immune landscapes identified local and systemic immune activation that corresponded to the sustained response to Y90-RE. Potential biomarkers associated with a positive clinical response were identified and a prediction model was built to identify sustained responders prior to treatment.

Critical Appraisal of the Impact of the Systematic Adoption of Advanced Minimally Invasive Hepatobiliary and Pancreatic Surgery on the Surgical Management of Mirizzi Syndrome.

BACKGROUND: Minimally invasive surgery (MIS) for Mirizzi syndrome (MS) remains a technically challenging procedure with a high open conversion rate. We critically evaluated the impact of the systematic adoption of MI-HBP surgery on the surgical outcomes of MS. METHODS: Ninety-five patients who underwent surgery for MS were retrospectively reviewed. Systematic adoption of advanced MI-HBP surgery started in 2012. The cohort was classified into a preadoption (2002-2012) (Era 1, n = 58) and post-adoption (2013-2017) (Era 2, n = 37). Furthermore, Era 2 was divided into a cohort operated by advanced minimally invasive surgeons (AMIS) (Era 2 AMIS, n = 19) and those by other surgeons (Era 2 others, n = 19). RESULTS: Comparison between Era 2 and Era 1 demonstrated a significant increase in the frequency of MIS attempted (89% vs 33%, p < 0.01), increase in the use of choledochoplasty (24% vs 2%, p < 0.01), increase operation time (180 min vs 150 min, p = 0.03) and significantly lower open conversion rate (24% vs 58%, p < 0.01). Comparison between Era 2 AMIS and Era 2 others demonstrated a significantly greater adoption of MIS (100% vs 78%, p = 0.046) with lower open conversion rate (5% vs 50%, p = 0.005). Comparison between all attempted MIS cases with open procedures demonstrated a significantly higher proportion of subtotal cholecystectomies performed (40% vs 23%, p = 0.04), choledochoplasty (17% vs 2%, p = 0.04) and shorter hospital stay (4 days vs 9 days, p < 0.01). CONCLUSIONS: Systematic adoption of advanced MI-HBP surgery allowed surgeons to perform MIS for MS more frequently and with a significantly lower open conversion rate. Patients who underwent successful MIS had the shortest hospital stay compared to patients who underwent open surgery or required open conversion.

Perioperative Outcomes of Laparoscopic Repeat Liver Resection for Recurrent HCC: Comparison with Open Repeat Liver Resection for Recurrent HCC and Laparoscopic Resection for Primary HCC.

BACKGROUND: This study aims to determine the safety and efficacy of laparoscopic repeat liver resection (LRLR) for recurrent hepatocellular carcinoma (rHCC). METHODS: Twenty patients underwent LRLR for rHCC between 2015 and 2017. The control groups consisted of 79 open RLR (ORLR) for rHCC and 185 LLR for primary HCC. We undertook propensity score-adjusted analyses (PSA) and 1:1 propensity score matching (PSM) for the comparison of LRLR versus ORLR. Comparison of LRLR versus LLR was done using multivariable regression models with adjustment for clinically relevant covariates. RESULTS: Twenty patients underwent LRLR with three open conversions (15%). Both PSA and 1:1-PSM demonstrated that LRLR was significantly associated with a shorter stay, superior disease-free survival (DFS) but longer operation time compared to ORLR. Comparison between LRLR versus LLR demonstrated that patients undergoing LRLR were significantly older, had smaller tumors, longer operation time and decreased frequency of Pringle's maneuver applied. There was no difference in other key perioperative outcomes. CONCLUSION: The results of this study demonstrate that in highly selected patients; LRLR for rHCC is feasible and safe. LRLR was associated with a shorter hospitalization but longer operation time compared to ORLR. Moreover, other than a longer operation time, LRLR was associated with similar perioperative outcomes compared to LLR for primary HCC.

Critical appraisal of the impact of individual surgeon experience on the outcomes of laparoscopic liver resection in the modern era: collective experience of multiple surgeons at a single institution with 324 consecutive cases.

BACKGROUND: Most studies analyzing the learning experience of laparoscopic liver resection (LLR) focused on the experience of one or two expert pioneering surgeons. This study aims to critically analyze the impact of individual surgeon experience on the outcomes of LLR based on the contemporary collective experiences of multiple surgeons at single institution. METHODS: Retrospective review of 324 consecutive LLR from 2006 to 2016. The cases were performed by 10 surgeons over various time periods. Four surgeons had individual experience with <20 cases, four surgeons with 20-30 cases, and two surgeons with >90 cases. The cohort was divided into two groups: comparing a surgeon's experience between the first 20, 30, 40, and 50 cases with patients treated thereafter. Similarly, we performed subset analyses for anterolateral lesions, posterosuperior lesions, and major hepatectomies. RESULTS: As individual surgeons gained increasing experience, this was significantly associated with older patients being operated, decreased hand-assistance, larger tumor size, increased liver resections, increased major resections, and increased resections of tumors located at the posterosuperior segments. This resulted in significantly longer operation time and increased use of Pringle maneuver but no difference in other outcomes. Analysis of LLR for tumors in the posterosuperior segments demonstrated that there was a significant decrease in conversion rates after a surgeon had experience with 20 LLR. For major hepatectomies, there was a significant decrease in morbidity, mortality, and length of stay after acquiring experience with 20 LLR. CONCLUSION: LLR can be safely adopted today especially for lesions in the anterolateral segments. LLR for lesions in the difficult posterosuperior segments and major hepatectomies especially in cirrhosis should only be attempted by surgeons who have acquired a minimum experience with 20 LLR.