A High-Dimensional Atlas of Human T Cell Diversity Reveals Tissue-Specific Trafficking and Cytokine Signatures.

Depending on the tissue microenvironment, T cells can differentiate into highly diverse subsets expressing unique trafficking receptors and cytokines. Studies of human lymphocytes have primarily focused on a limited number of parameters in blood, representing an incomplete view of the human immune system. Here, we have utilized mass cytometry to simultaneously analyze T cell trafficking and functional markers across eight different human tissues, including blood, lymphoid, and non-lymphoid tissues. These data have revealed that combinatorial expression of trafficking receptors and cytokines better defines tissue specificity. Notably, we identified numerous T helper cell subsets with overlapping cytokine expression, but only specific cytokine combinations are secreted regardless of tissue type. This indicates that T cell lineages defined in mouse models cannot be clearly distinguished in humans. Overall, our data uncover a plethora of tissue immune signatures and provide a systemic map of how T cell phenotypes are altered throughout the human body.

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 (AHCC) trials group (NCT03267641), we recruited one of the largest prospective cohorts of 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 provided a rich multi-omics resource for understanding tumor heterogeneity and clinical trajectories. CLINICAL TRIAL NUMBER: NCT03267641 (Observational cohort) IMPACT AND IMPLICATIONS: This prospective study, utilizing comprehensive multi-sector, multi-omics sequencing and clinical data from surgically resected HCC, reveals critical insights into the role of tumor evolution and intra-tumor heterogeneity (ITH) in determining the prognosis of Hepatocellular Carcinoma (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 developing personalized therapies tailored to specific tumor evolutionary and transcriptomic profiles. The co-existence of multiple sub-types 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.

Short-term outcomes of laparoscopic and robotic limited resections of pancreatic neuroendocrine tumours of the uncinate process: Report of six cases and review of the literature.

INTRODUCTION: Minimally invasive surgery (MIS) for limited resections for pancreatic uncinate lesions is not widely performed but can adequately treat benign or low-grade malignant lesions. The aim of this study was to evaluate the short-term outcomes of MIS-limited pancreatic resections for patients with suspected pancreatic neuroendocrine tumours (PNETs). PATIENTS AND METHODS: This was a retrospective study of six consecutive patients who underwent MIS for PNET within a single institution between 2017 and 2022. RESULTS: Six patients underwent limited pancreas-preserving MIS of the uncinate process (uncinectomy or enucleation), of which two were performed through the robotic approach and four through laparoscopic approach. The median operation time was 212.5 (175-338.75) min, and the median blood loss was 50 (50-112.5) ml. The median post-operative hospital length of stay was 5.5 (3.75-11.5) days. Two patients (33.3%) had major post-operative morbidities (Clavien-Dindo ≥Grade 3). There were no open conversions or post-operative mortalities. Five patients had histologically proven Grade 1 neuroendocrine tumours. One was T2 and four were T1. CONCLUSIONS: This study suggests that limited MIS resections of pancreatic uncinate PNETs are a feasible procedure with good patient outcomes. It offers a safe alternative to radical surgical resections like pancreatoduodenectomies in selected patients with low-grade malignant or benign tumours.

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.

Association of standardized liver volume and body mass index with outcomes of minimally invasive liver resections.

INTRODUCTION: While minimally invasive liver resections (MILR) have demonstrated advantages in improved post-operative recovery, widespread adoption is hampered by inherent technical difficulties. Our study attempts to analyze the role of anthropometric measures in MILR-related outcomes. METHODS: Between 2012 and 2020, 676 consecutive patients underwent MILR at the Singapore General Hospital of which 565 met study criteria and were included. Patients were stratified based on Body Mass Index (BMI) as well as Standardized Liver Volumes (SLV). Associations between BMI and SLV to selected peri-operative outcomes were analyzed using restricted cubic splines. RESULTS: A BMI of ≥ 29 was associated with increase in blood loss [Mean difference (MD) 69 mls, 95% CI 2 to 137] as well as operative conversions [Relative Risk (RR) 1.63, 95% CI 1.02 to 2.62] among patients undergoing MILR while a SLV of 1600 cc or higher was associated with an increase in blood loss (MD 30 mls, 95% CI 10 to 49). In addition, a BMI of ≤ 20 was associated with an increased risk of major complications (RR 2.25, 95% 1.16 to 4.35). The magnitude of differences observed in these findings increased with each unit change in BMI and SLV. CONCLUSION: Both BMI and SLV were useful anthropometric measures in predicting peri-operative outcomes in MILR and may be considered for incorporation in future difficulty scoring systems for MILR.

Impact of non-liver-related previous abdominal surgery on the difficulty of minimally invasive liver resections: a propensity score-matched controlled study.

INTRODUCTION: The presence of previous abdominal surgery (PAS) has traditionally been considered to add difficulty to and increase risk of complications of laparoscopic procedures. This study aims to analyse the impact of non-liver-related PAS on the difficulty of minimally invasive liver resections (MILRs). MATERIALS AND METHODS: After exclusion of patients with concomitant major surgical procedures as well as previous liver resections, 515 consecutive patients undergoing MILR in Singapore General Hospital from 2006 to 2019 were analysed, consisting of 161 MILR in patients with previous abdominal surgery (WPAS) and 354 MILR in patients without previous abdominal surgery (WOPAS). Propensity score-matched (PSM) comparison was performed between WPAS and WOPAS groups. In addition, subgroup analysis was made comparing previous upper or lower abdominal surgery and open versus minimally invasive approach of PAS. Outcomes measured include those associated with operative difficulty such as open conversion rates, operative time, blood loss, as well as morbidity and mortality rates. RESULTS: MILR outcomes in patients WPAS are not inferior to those WOPAS. Overall open conversion rate was 8.2%, higher in patients WOPAS compared to patients WPAS (11.9% versus 3.5%, p = 0.015). Operating time (p = 0.942), blood loss (p = 0.063), intraoperative blood transfusion (p = 0.750), length of hospital stay (p = 0.206), morbidity (p = 0.217) and 30- and 90-day mortality (p = 1 & p = 0.367) were comparable between the two groups and subgroup analysis. CONCLUSION: Outcomes of MILR in patients with previous non-liver-related abdominal surgery are not inferior to patients without previous abdominal surgery.

Propensity-Score Matched Analyses Comparing Clinical Outcomes of Minimally Invasive Versus Open Distal Pancreatectomies: A Single-Center Experience.

BACKGROUND: Minimally invasive distal pancreatectomy (MIDP) is being adopted increasingly worldwide. This study aimed to compare the short-term outcomes of patients who underwent MIDP versus open distal pancreatectomy (ODP). METHODS: A retrospective review of all patients who underwent a DP in our institution between 2005 and 2019 was performed. Propensity score matching based on relevant baseline factors was used to match patients in the ODP and MIDP groups in a 1:1 manner. Outcomes reported include operative duration, blood loss, postoperative length of stay, morbidity, mortality, postoperative pancreatic fistula rates, reoperation and readmission. RESULTS: In total, 444 patients were included in this study. Of 122 MIDP patients, 112 (91.8%) could be matched. After matching, the median operating time for MIDP was significantly longer than ODP [260 min (200-346.3) vs 180 (135-232.5), p < 0.001], while postoperative stay for MIDP was significantly shorter [median 6 days (5-8) versus 7 days (6-9), p = 0.015]. There were no significant differences noted in any of the other outcomes measured. Over time, we observed a decrease in the operation times of MIDP performed at our institution. CONCLUSION: Adoption of MIDP offers advantages over ODP in terms of a shorter postoperative hospital stay, without an increase in morbidity and/or mortality but at the expense of a longer operation time.

Repeat hepatectomy versus radiofrequency ablation in management of recurrent hepatocellular carcinoma: an average treatment effect analysis.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with high rates of recurrence post-resection. Repeat hepatectomy (RH) and radiofrequency ablation (RFA) are the mainstays for managing recurrent HCC following initial curative resection. This retrospective study aims to determine the average treatment effect of RH and RFA in patients with recurrent HCC. PATIENTS AND METHODS: From 2000 to 2016, a total of 219 consecutive patients with recurrent HCC who underwent either RH or RFA were included in the study. The analysis was performed using inverse probability of treatment weighting (IPTW), and propensity score-matched (PSM) methods. RESULTS: The minor and major post-operative morbidity after propensity score-matched analysis for the RH group was 30.0% and 6.0%, respectively, and 19.2% and 0.0% (p = 0.1006), respectively, for the RFA group. After propensity score matching, the median OS for RH and RFA was 85.5 (IQR, 33.5-not reached) and 53.3 months (IQR, 27.5-not reached) (p = 0.8474), respectively. There was no significant difference in 90-day mortality between both groups (p = 0.1287). RH showed improved long-term overall survival over RFA at the third [71.3% versus 65.7% (p = 0.0432)], fifth [59.9% versus 45.4% (p = 0.0271)] and tenth [35.4% versus 32.2% (p = 0.0132)] year follow-up, respectively. Median time to recurrence was 11.1 (IQR, 5.0-33.2) and 28.0 months (IQR, 9.1-not reached) (p = 0.0225) for the RFA and RH group, respectively. CONCLUSIONS: RH confers a late survival benefit compared with RFA for patients with recurrent HCC despite a higher morbidity rate.

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.

Impact of liver cirrhosis on the difficulty of minimally-invasive liver resections: a 1:1 coarsened exact-matched controlled study.

INTRODUCTION: The impact of liver cirrhosis on the difficulty of minimal invasive liver resection (MILR) remains controversial and current difficulty scoring systems do not take in to account the presence of cirrhosis as a significant factor in determining the difficulty of MILR. We hypothesized that the difficulty of MILR is affected by the presence of cirrhosis. Hence, we performed a 1:1 matched-controlled study comparing the outcomes between patients undergoing MILR with and without cirrhosis including the Iwate system and Institut Mutualiste Montsouris (IMM) system in the matching process. METHODS: Between 2006 and 2019, 598 consecutive patients underwent MILR of which 536 met the study inclusion criteria. There were 148 patients with cirrhosis and 388 non-cirrhotics. One-to-one coarsened exact matching identified approximately exact matches between 100 cirrhotic patients and 100 non-cirrhotic patients. RESULTS: Comparison between MILR patients with cirrhosis and non-cirrhosis in the entire cohort demonstrated that patients with cirrhosis were associated with a significantly increased open conversion rate, transfusion rate, need for Pringles maneuver, postoperative, stay, postoperative morbidity and postoperative 90-day mortality. After 1:1 coarsened exact matching, MILR with cirrhosis were significantly associated with an increased open conversion rate (15% vs 6%, p = 0.03), operation time (261 vs 238 min, p < 0.001), blood loss (607 vs 314 mls, p = 0.002), transfusion rate (22% vs 9%, p = 0.001), need for application of Pringles maneuver (51% vs 34%, p = 0.010), postoperative stay (6 vs 4.5 days, p = 0.004) and postoperative morbidity (26% vs 13%, p = 0.029). CONCLUSION: The presence of liver cirrhosis affected both the intraoperative technical difficulty and postoperative outcomes of MILR and hence should be considered an important parameter to be included in future difficulty scoring systems for MILR.

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.

Early Prediction of Post-hepatectomy Liver Failure in Patients Undergoing Major Hepatectomy Using a PHLF Prognostic Nomogram.

BACKGROUND: Liver resection (LR) is the main modality of treatment for hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM). Post-hepatectomy liver failure (PHLF) remains the most dreaded complication. We aim to create a prognostic score for early risk stratification of patients undergoing LR. METHODOLOGY: Clinical and operative data of 472 patients between 2000 and 2016 with HCC or CRLM undergoing major hepatectomy were extracted and analysed from a prospectively maintained database. PHLF was defined using the 50-50 criteria. RESULTS: Liver cirrhosis and fatty liver were histologically confirmed in 35.6% and 53% of patients. 4.7% (n = 22) of patients had PHLF. A 90-day mortality was 5.1% (n = 24). Pre-operative albumin-bilirubin score (p = 0.0385), prothrombin time (p < 0.0001) and the natural logarithm of the ratio of post-operative day 1 to pre-operative serum bilirubin (SB) (ln(POD1Bil/pre-opBil); p < 0.0001) were significantly independent predictors of PHLF. The PHLF prognostic nomogram was developed using these factors with receiver operating curve showing area under curve of 0.88. Excellent sensitivity (94.7%) and specificity (95.7%) for the prediction of PHLF (50-50 criteria) were achieved at cut-offs of 9 and 11 points on this model. This score was also predictive of PHLF according to PeakBil > 7 and International Study Group for Liver Surgery criteria, intensive care unit admissions, length of stay, all complications, major complications, re-admissions and mortality (p < 0.05). CONCLUSIONS: The PHLF nomogram ( https://tinyurl.com/SGH-PHLF-Risk-Calculator ) can serve as a useful tool for early identification of patients at high risk of PHLF before the 'point of no return'. This allows enforcement of closer monitoring, timely intervention and mitigation of adverse outcomes.

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.

Impact of multidisciplinary tumour boards (MTB) on the clinicopathological characteristics and outcomes of resected colorectal liver metastases across time.

BACKGROUND: Resection of colorectal liver metastases (CLM) has been established as the standard of care. This study aims to compare the change in clinicopathological characteristics of patients who underwent curative resection of CLM across two time periods-2000 to 2010 (P1) and 2011 to 2016 (P2) and evaluate the prognostic impact of these characteristics on survival outcomes. METHODS: Patients who undergo liver resection for CLM at Singapore General Hospital from January 2000 to December 2016 were identified from a prospectively maintained database. The primary end point was overall survival. RESULTS: There were 183/318 (57.5%) patients and 135/318 (42.5%) patients in P1 and P2, respectively. There was a lower proportion of patients who had nodal metastases from primary colorectal cancer and clinical risk score (CRS) less than 3 in P2 when compared to P1. There was no difference in survival between both time periods. Independent predictors of survival for the cohort were CEA levels ≥ 200 ng/ml, primary tumour grade and lymph nodal status. Independent predictors of poor survival in P1 were poorly differentiated colorectal cancer and nodal metastases while in P2, independent predictors of poor survival were multiple liver metastases and nodal metastases. CONCLUSION: Nodal metastases from primary colorectal cancer are an independent predictor of poor survival across time for resectable CLM. Although there is no difference in survival between the two time periods, patients with multiple liver metastases should be carefully considered prior to surgery as it is also an independent predictor of overall survival.

Effect of remote ischemic preConditioning on liver injury in patients undergoing liver resection: the ERIC-LIVER trial.

OBJECTIVE: Novel hepatoprotective strategies are needed to improve clinical outcomes during liver surgery. There is mixed data on the role of remote ischemic preconditioning (RIPC). We investigated RIPC in partial hepatectomy for primary hepatocellular carcinoma (HCC). METHODS: This was a Phase II, single-center, sham-controlled, randomized controlled trial (RCT). The primary hypothesis was that RIPC would reduce acute liver injury following surgery indicated by serum alanine transferase (ALT) 24 h following hepatectomy in patients with primary HCC, compared to sham. Patients were randomized to receive either four cycles of 5 min/5 min arm cuff inflation/deflation immediately prior to surgery, or sham. Secondary endpoints included clinical, biochemical and pathological outcomes. Liver function measured by Indocyanine Green pulse densitometry was performed in a subset of patients. RESULTS: 24 and 26 patients were randomized to RIPC and control groups respectively. The groups were balanced for baseline characteristics, except the duration of operation was longer in the RIPC group. Median ALT at 24 h was similar between groups (196 IU/L IQR 113.5-419.5 versus 172.5 IU/L IQR 115-298 respectively, p = 0.61). Groups were similar in secondary endpoints. CONCLUSION: This RCT did not demonstrate beneficial effects with RIPC on serum ALT levels 24 h after partial hepatectomy.

Changing trends and outcomes associated with the adoption of minimally invasive pancreatic surgeries: A single institution experience with 150 consecutive procedures in Southeast Asia.

BACKGROUND: Minimally invasive pancreatic surgeries (MIPS) are increasingly adopted worldwide. However, it remains uncertain if these reported experiences are reproducible throughout the world today. This study examines the safety and evolution of MIPS at a single institution in Southeast Asia. METHODS: This is a retrospective review of 150 consecutive patients who underwent MIPS between 2006 and 2018 of which 135 cases (90%) were performed since 2012. To determine the evolution of MIPS, the study population was stratified into 3 equal groups of 50 patients. Comparison was also made between pancreatoduodenectomies (PD), distal pancreatectomies (DP) and other pancreatic surgeries. RESULTS: One hundred and fifty patients underwent MIPS (103 laparoscopic, 45 robotic and 2 hand-assisted). Forty-three patients underwent PD, 93 DP and 14 other MIPS. There were 21 (14.0%) open conversions. There was an exponential increase in caseload over the study period. Comparison across the 3 time periods demonstrated that patients were significantly more likely to have a higher American Society of Anesthesiologists score, older, undergo PD and a longer operation time. The conversion rate decreased from 28% to 0% and increased again to 14% across the 3 time periods. Comparison between the various types of MIPS demonstrated that patients who underwent PD were significantly older, more likely to have symptomatic tumours, had longer surgery time, increased blood loss, increased frequency of extended pancreatectomies, increased frequency of hybrid procedures, longer post-operative stay, increased post-operative morbidity rate and increased post-operative major morbidity rate. CONCLUSION: The case volume of MIPS increased rapidly at our institution over the study period. Furthermore, although the indications for MIPS expanded to include more complex procedures in higher risk patients, there was no change in key perioperative outcomes.