Positive selection of somatically mutated clones identifies adaptive pathways in metabolic liver disease.

Somatic mutations in nonmalignant tissues accumulate with age and injury, but whether these mutations are adaptive on the cellular or organismal levels is unclear. To interrogate genes in human metabolic disease, we performed lineage tracing in mice harboring somatic mosaicism subjected to nonalcoholic steatohepatitis (NASH). Proof-of-concept studies with mosaic loss of Mboat7, a membrane lipid acyltransferase, showed that increased steatosis accelerated clonal disappearance. Next, we induced pooled mosaicism in 63 known NASH genes, allowing us to trace mutant clones side by side. This in vivo tracing platform, which we coined MOSAICS, selected for mutations that ameliorate lipotoxicity, including mutant genes identified in human NASH. To prioritize new genes, additional screening of 472 candidates identified 23 somatic perturbations that promoted clonal expansion. In validation studies, liver-wide deletion of Tbx3, Bcl6, or Smyd2 resulted in protection against hepatic steatosis. Selection for clonal fitness in mouse and human livers identifies pathways that regulate metabolic disease.

Nuclear Pores Promote Lethal Prostate Cancer by Increasing POM121-Driven E2F1, MYC, and AR Nuclear Import.

Nuclear pore complexes (NPCs) regulate nuclear-cytoplasmic transport, transcription, and genome integrity in eukaryotic cells. However, their functional roles in cancer remain poorly understood. We interrogated the evolutionary transcriptomic landscape of NPC components, nucleoporins (Nups), from primary to advanced metastatic human prostate cancer (PC). Focused loss-of-function genetic screen of top-upregulated Nups in aggressive PC models identified POM121 as a key contributor to PC aggressiveness. Mechanistically, POM121 promoted PC progression by enhancing importin-dependent nuclear transport of key oncogenic (E2F1, MYC) and PC-specific (AR-GATA2) transcription factors, uncovering a pharmacologically targetable axis that, when inhibited, decreased tumor growth, restored standard therapy efficacy, and improved survival in patient-derived pre-clinical models. Our studies molecularly establish a role of NPCs in PC progression and give a rationale for NPC-regulated nuclear import targeting as a therapeutic strategy for lethal PC. These findings may have implications for understanding how NPC deregulation contributes to the pathogenesis of other tumor types.

Prolonged hypernutrition impairs TREM2-dependent efferocytosis to license chronic liver inflammation and NASH development.

Obesity-induced chronic liver inflammation is a hallmark of nonalcoholic steatohepatitis (NASH)-an aggressive form of nonalcoholic fatty liver disease. However, it remains unclear how such a low-grade, yet persistent, inflammation is sustained in the liver. Here, we show that the macrophage phagocytic receptor TREM2, induced by hepatocyte-derived sphingosine-1-phosphate, was required for efferocytosis of lipid-laden apoptotic hepatocytes and thereby maintained liver immune homeostasis. However, prolonged hypernutrition led to the production of proinflammatory cytokines TNF and IL-1ß in the liver to induce TREM2 shedding through ADAM17-dependent proteolytic cleavage. Loss of TREM2 resulted in aberrant accumulation of dying hepatocytes, thereby further augmenting proinflammatory cytokine production. This ultimately precipitated a vicious cycle that licensed chronic inflammation to drive simple steatosis transition to NASH. Therefore, impaired macrophage efferocytosis is a previously unrecognized key pathogenic event that enables chronic liver inflammation in obesity. Blocking TREM2 cleavage to restore efferocytosis may represent an effective strategy to treat NASH.

Opposing roles of hepatic stellate cell subpopulations in hepatocarcinogenesis.

Hepatocellular carcinoma (HCC), the fourth leading cause of cancer mortality worldwide, develops almost exclusively in patients with chronic liver disease and advanced fibrosis1,2. Here we interrogated functions of hepatic stellate cells (HSCs), the main source of liver fibroblasts3, during hepatocarcinogenesis. Genetic depletion, activation or inhibition of HSCs in mouse models of HCC revealed their overall tumour-promoting role. HSCs were enriched in the preneoplastic environment, where they closely interacted with hepatocytes and modulated hepatocarcinogenesis by regulating hepatocyte proliferation and death. Analyses of mouse and human HSC subpopulations by single-cell RNA sequencing together with genetic ablation of subpopulation-enriched mediators revealed dual functions of HSCs in hepatocarcinogenesis. Hepatocyte growth factor, enriched in quiescent and cytokine-producing HSCs, protected against hepatocyte death and HCC development. By contrast, type I collagen, enriched in activated myofibroblastic HSCs, promoted proliferation and tumour development through increased stiffness and TAZ activation in pretumoural hepatocytes and through activation of discoidin domain receptor 1 in established tumours. An increased HSC imbalance between cytokine-producing HSCs and myofibroblastic HSCs during liver disease progression was associated with increased HCC risk in patients. In summary, the dynamic shift in HSC subpopulations and their mediators during chronic liver disease is associated with a switch from HCC protection to HCC promotion.

Emerging Roles of Spatial Transcriptomics in Liver Research.

Spatial transcriptomics, leveraging sequencing- and imaging-based techniques, has emerged as a groundbreaking technology for mapping gene expression within the complex architectures of tissues. This approach provides an in-depth understanding of cellular and molecular dynamics across various states of healthy and diseased livers. Through the integration of sophisticated bioinformatics strategies, it enables detailed exploration of cellular heterogeneity, transitions in cell states, and intricate cell-cell interactions with remarkable precision. In liver research, spatial transcriptomics has been particularly revelatory, identifying distinct zonated functions of hepatocytes that are crucial for understanding the metabolic and detoxification processes of the liver. Moreover, this technology has unveiled new insights into the pathogenesis of liver diseases, such as the role of lipid-associated macrophages in steatosis and endothelial cell signals in liver regeneration and repair. In the domain of liver cancer, spatial transcriptomics has proven instrumental in delineating intratumor heterogeneity, identifying supportive microenvironmental niches and revealing the complex interplay between tumor cells and the immune system as well as susceptibility to immune checkpoint inhibitors. In conclusion, spatial transcriptomics represents a significant advance in hepatology, promising to enhance our understanding and treatment of liver diseases.

Risk stratification and early detection biomarkers for precision HCC screening.

Hepatocellular carcinoma (HCC) mortality remains high primarily due to late diagnosis as a consequence of failed early detection. Professional societies recommend semi-annual HCC screening in at-risk patients with chronic liver disease to increase the likelihood of curative treatment receipt and improve survival. However, recent dynamic shift of HCC etiologies from viral to metabolic liver diseases has significantly increased the potential target population for the screening, whereas annual incidence rate has become substantially lower. Thus, with the contemporary HCC etiologies, the traditional screening approach might not be practical and cost-effective. HCC screening consists of (i) definition of rational at-risk population, and subsequent (ii) repeated application of early detection tests to the population at regular intervals. The suboptimal performance of the currently available HCC screening tests highlights an urgent need for new modalities and strategies to improve early HCC detection. In this review, we overview recent developments of clinical, molecular, and imaging-based tools to address the current challenge, and discuss conceptual framework and approaches of their clinical translation and implementation. These encouraging progresses are expected to transform the current "one-size-fits-all" HCC screening into individualized precision approaches to early HCC detection and ultimately improve the poor HCC prognosis in the foreseeable future.

Robot-assisted transcervical esophagectomy with a bilateral cervical approach for thoracic esophagectomy.

BACKGROUND: Thoracic esophageal cancer resection through the neck approach has recently been reported as mediastinoscopic surgery. We present the first report of a new minimally invasive technique for thoracic esophageal cancer: robot-assisted transcervical esophagectomy with a bilateral cervical approach. METHODS: Ten cases of robot-assisted bilateral transcervical esophagectomy performed at the National Cancer Center Hospital East, Japan, from February 2023 to August 2023 were reviewed. The short-term surgical outcomes were presented, and the feasibility and efficacy of this procedure were discussed. RESULTS: The mean operation time for the cervical procedure was 184.2 ± 23.6 min. The total time for the whole procedure was 472.7 ± 28.4 min, and total intraoperative blood loss was 162.2 ± 40.0 ml. Among the 10 cases, one patient developed recurrent nerve paralysis, one patient developed pulmonary complications, and no patients developed postoperative pneumonia. The median postoperative hospital stay was 22 (range: 12-43) days. No patients developed severe postoperative surgical complications, which were graded as Clavien-Dindo ≥ III. The total number of surgically harvested mediastinal lymph nodes was 37.2 ± 11.2. CONCLUSIONS: Robot-assisted bilateral transcervical esophagectomy, a novel procedure for thoracic esophageal cancer, was safe and feasible. Using this procedure, the incidence of recurrent nerve palsy, which is a problem with transcervical esophagectomy and mediastinoscopic esophagectomy, is expected to decrease.

Efficiency of conversion surgery for esophageal squamous cell carcinoma with solitary abdominal para-aortic lymph node metastasis.

PURPOSE: Abdominal para-aortic lymph nodes (PANs) are sites of distant metastasis in esophageal squamous cell cancer (ESCC). The prognosis of patients with Stage IVB ESCC and abdominal PAN metastasis is extremely poor. However, chemotherapy for ESCC has recently been developed, and the effectiveness of combined induction therapy and conversion surgery remains unclear. The primary objective of this study was to evaluate the short- and long-term outcomes of conversion surgery for ESCC and solitary abdominal PAN metastases after induction therapy. METHODS: Thirteen patients who underwent conversion esophagectomy for cStage IVB ESCC with solitary abdominal PAN metastasis after induction therapy between January 2017 and October 2022 at our institution were enrolled. The short- and long-term outcomes of conversion surgery were retrospectively evaluated. RESULTS: Three patients (23.1%) had pathological abdominal PAN metastasis, and six patients (46.2%) without pathological abdominal PAN metastasis showed that chemotherapy eliminated the tumors in the abdominal PAN. Three patients (23.1%) had postoperative complications of Clavien-Dindo grade II or higher. The 3-year overall and recurrence-free survival rates were 83.1% and 51.3%, respectively. CONCLUSIONS: Our findings showed that conversion surgery for ESCC and solitary abdominal PAN metastasis led to a good prognosis when induction therapy was successful.

A novel device to assess the oxygen saturation and congestion status of the gastric conduit in thoracic esophagectomy.

BACKGROUND: In thoracic esophagectomy, anastomotic leakage is one of the most important surgical complications. Indocyanine green (ICG) is the most widely used method to assess tissue blood flow; however, this technique has been pointed out to have disadvantages such as difficulty in evaluating the degree of congestion, lack of objectivity in evaluating the degree of staining, and bias easily caused by ICG injection, camera distance, and other factors. Evaluating tissue oxygen saturation (StO2) overcomes these disadvantages and can be performed easily and repeatedly. It is also possible to measure objective values including the degree of congestion. We evaluate novel imaging technology to assess tissue oxygen saturation (StO2) in the gastric conduit during thoracic esophagectomy. METHODS: Fifty patients were enrolled, with seven excluded due to intraoperative findings, leaving 43 for analysis. These patients underwent thoracic esophagectomy for esophageal cancer. The device was used intraoperatively to evaluate tissue oxygen saturation (StO2) and total hemoglobin index (T-HbI), which guided the optimal site for gastric tube anastomosis. The efficacies of StO2 and T-HbI in relation to short-term outcomes were analyzed. RESULTS: StO2, indicating blood supply to the gastric tube, remained stable beyond the right gastroepiploic artery (RGEA) end but significantly decreased distally to the demarcation line (p <  0.05). T-HbI, indicative of congestion, significantly decreased past the RGEA (p <  0.05). Three patients experienced anastomotic leakage. These patients exhibited significantly lower StO2 (p <  0.01) and higher T-HbI (p <  0.01) at both the RGEA end and the demarcation line. Furthermore, the anastomotic site, usually within 3 cm of the RGEA's anorectal side, also showed significantly lower StO2 (p <  0.01) and higher T-HbI (p <  0.01) in patients with anastomotic leakage. CONCLUSIONS: The novel device provides real-time, objective evaluations of blood flow and congestion in the gastric tube. It proves useful for safer reconstruction during thoracic esophagectomy, particularly by identifying optimal anastomosis sites and predicting potential anastomotic leakage.

Clinico-histological and molecular features of hepatocellular carcinoma from nonalcoholic fatty liver disease.

Patients with nonalcoholic fatty liver disease (NAFLD) continue to increase with the epidemics of obesity, and NAFLD is estimated to become the most prevalent etiology of hepatocellular carcinoma (HCC). Recently, NAFLD-HCC has been recognized to have clinico-histologically and molecularly distinct features from those from other etiologies, including a lower incidence rate of HCC and less therapeutic efficacy to immune checkpoint inhibitors (ICIs). Consistent with the clinical observations that up to 50% of NAFLD-HCC occurs in the absence of cirrhosis, the imbalance of pro- and antitumorigenic hepatic stellate cells termed as myHSC and cyHSC can contribute to the creation of an HCC-prone hepatic environment, independent of the absolute fibrosis abundance. Immune deregulations by accumulated metabolites in NAFLD-affected livers, such as a fatty-acid-induced loss of cytotoxic CD4 T cells serving for immune surveillance and "auto-aggressive" CXCR6+ CD8 T cells, may promote hepatocarcinogenesis and diminish therapeutic response to ICIs. Steatohepatitic HCC (SH-HCC), characterized by the presence of fat accumulation in tumor cells, ballooned tumor cells, Mallory-Denk body, interstitial fibrosis, and intratumor immune cell infiltration, may represent a metabolic reprogramming for adapting to a lipid-rich tumor microenvironment by downregulating CPT2 and leveraging its intermediates as an "oncometabolite." Genome-wide analyses suggested that SH-HCC may be more responsive to ICIs given its mutual exclusiveness with ß-catenin mutation/activation that promotes immune evasion. Thus, further understanding of NAFLD-specific hepatocarcinogenesis and HCC would enable us to improve the current daily practice and eventually the prognoses of patients with NAFLD.

Molecular Signature Predictive of Long-Term Liver Fibrosis Progression to Inform Antifibrotic Drug Development.

BACKGROUND & AIMS: There is a major unmet need to assess the prognostic impact of antifibrotics in clinical trials because of the slow rate of liver fibrosis progression. We aimed to develop a surrogate biomarker to predict future fibrosis progression. METHODS: A fibrosis progression signature (FPS) was defined to predict fibrosis progression within 5 years in patients with hepatitis C virus and nonalcoholic fatty liver disease (NAFLD) with no to minimal fibrosis at baseline (n = 421) and was validated in an independent NAFLD cohort (n = 78). The FPS was used to assess response to 13 candidate antifibrotics in organotypic ex vivo cultures of clinical fibrotic liver tissues (n = 78) and cenicriviroc in patients with nonalcoholic steatohepatitis enrolled in a clinical trial (n = 19, NCT02217475). A serum protein-based surrogate FPS was developed and tested in a cohort of compensated cirrhosis patients (n = 122). RESULTS: A 20-gene FPS was defined and validated in an independent NAFLD cohort (adjusted odds ratio, 10.93; area under the receiver operating characteristic curve, 0.86). Among computationally inferred fibrosis-driving FPS genes, BCL2 was confirmed as a potential pharmacologic target using clinical liver tissues. Systematic ex vivo evaluation of 13 candidate antifibrotics identified rational combination therapies based on epigallocatechin gallate, which were validated for enhanced antifibrotic effect in ex vivo culture of clinical liver tissues. In patients with nonalcoholic steatohepatitis treated with cenicriviroc, FPS modulation was associated with 1-year fibrosis improvement accompanied by suppression of the E2F pathway. Induction of the PPARα pathway was absent in patients without fibrosis improvement, suggesting a benefit of combining PPARα agonism to improve the antifibrotic efficacy of cenicriviroc. A 7-protein serum protein-based surrogate FPS was associated with the development of decompensation in cirrhosis patients. CONCLUSION: The FPS predicts long-term fibrosis progression in an etiology-agnostic manner, which can inform antifibrotic drug development.

[Management of Postoperative Infectious Complications After Thoracic Esophagectomy].

Although minimally invasive procedures such as thoracoscopic surgery and robot-assisted surgery have become increasingly popular in esophageal cancer in recent years, perioperative management remains a very important topic. However, perioperative management is still an extremely important issue, as esophagectomy is still a highly invasive procedure. Especially in recent years, as the patient population ages, it is expected that we will have more and more opportunities to deal with patients with various pre-existing medical conditions in addition to the original decline in physical function. In this article, we discuss the management of infectious complications in the perioperative management of esophageal surgery, with a particular focus on esophagectomy and reconstruction.

The feasibility of post-photodynamic therapy salvage esophagectomy in patients with esophageal squamous cell carcinoma treated with definitive chemoradiotherapy.

BACKGROUND: Photodynamic therapy (PDT) is a minimally invasive salvage treatment for local residual or recurrent lesions that persist after the definitive chemoradiotherapy (dCRT) of esophageal cancer. However, esophageal cancer persistence after PDT is associated with a poor prognosis. Although esophagectomy is a curative treatment option, few studies have evaluated its efficacy. Thus, this study aimed to evaluate the outcomes of salvage esophagectomy after PDT. METHODS: 14 patients who underwent salvage esophagectomy for residual or recurrent esophageal cancer after PDT between April 2006 and November 2022 at our institution, were enrolled. The short-term (e.g., blood loss, operative time, R0 rate, postoperative complications, and postoperative hospital stay) and long-term (e.g., overall survival [OS] and recurrence-free survival [RFS]) of salvage esophagectomy after PDT were evaluated retrospectively. RESULTS: The median operative time and intraoperative blood loss were 355 min and 350 ml, respectively. Eight patients (57.1%) had postoperative complications of Clavien-Dindo grade II or more. The median postoperative hospital stay was 20.5 days. The 3-year OS and RFS rates were 23.5% (95% confidence interval [CI] 5.7-48.0) and 16.3% (95% CI 2.7-40.3), respectively. Seven patients with an R0 had significantly longer OS than the seven patients with R1 and 2 (p = 0.045). The 3-year OS rate for patients with R0 was 52.6%. CONCLUSIONS: Although salvage esophagectomy after PDT carries certain risks, patients who achieved an R0 had a promising long-term prognosis. The location and size of the lesion may be critical factors in determining whether R0 can be achieved with salvage esophagectomy after PDT.

Surgical outcomes of reconstruction using the gastric tube and free jejunum for cervical esophageal cancer: analysis using the National Clinical Database of Japan.

BACKGROUND: Cervical esophageal cancer accounts for a small proportion of all esophageal cancers. Therefore, studies examining this cancer include a small patient cohort. Most patients with cervical esophageal cancer undergo reconstruction using a gastric tube or free jejunum after esophagectomy. We examined the current status of postoperative morbidity and mortality of cervical esophageal cancer based on big data. METHODS: Based on the Japan National Clinical Database, 807 surgically treated patients with cervical esophageal cancer were enrolled between January 1, 2016, and December 31, 2019. Surgical outcomes were retrospectively reviewed for each reconstructed organ using gastric tubes and free jejunum. RESULTS: The incidence of postoperative complications related to reconstructed organs was higher in the gastric tube reconstruction (17.9%) than in the free jejunum (6.7%) for anastomotic leakage (p < 0.01), but not significantly different for reconstructed organ necrosis (0.4% and 0.3%, respectively). The incidence rates of overall morbidity, pneumonia, 30-day reoperation, tracheal necrosis, and 30-day mortality using these reconstruction methods were 64.7% and 59.7%, 16.7% and 11.1%, 9.3% and 11.4%, 2.2% and 1.6%, and 1.2% and 0.0%, respectively. Only pneumonia was more common in the gastric tube reconstruction group (p = 0.03), but was not significantly different for any other complication. CONCLUSIONS: The incidence of overall morbidities and reoperation, especially anastomotic leakage after gastric tube reconstruction, suggested a necessity for further improvement. However, the incidence of fatal complications, such as tracheal necrosis or reconstructed organ necrosis, was low for both reconstruction methods, and the mortality rate was acceptable as a means of radical treatment.

Cell-based cccDNA reporter assay combined with functional genomics identifies YBX1 as HBV cccDNA host factor and antiviral candidate target.

OBJECTIVES: Chronic hepatitis B virus (HBV) infection is a leading cause of liver disease and hepatocellular carcinoma. A key feature of HBV replication is the synthesis of the covalently close circular (ccc)DNA, not targeted by current treatments and whose elimination would be crucial for viral cure. To date, little is known about cccDNA formation. One major challenge to address this urgent question is the absence of robust models for the study of cccDNA biology. DESIGN: We established a cell-based HBV cccDNA reporter assay and performed a loss-of-function screen targeting 239 genes encoding the human DNA damage response machinery. RESULTS: Overcoming the limitations of current models, the reporter assay enables to quantity cccDNA levels using a robust ELISA as a readout. A loss-of-function screen identified 27 candidate cccDNA host factors, including Y box binding protein 1 (YBX1), a DNA binding protein regulating transcription and translation. Validation studies in authentic infection models revealed a robust decrease in HBV cccDNA levels following silencing, providing proof-of-concept for the importance of YBX1 in the early steps of the HBV life cycle. In patients, YBX1 expression robustly correlates with both HBV load and liver disease progression. CONCLUSION: Our cell-based reporter assay enables the discovery of HBV cccDNA host factors including YBX1 and is suitable for the characterisation of cccDNA-related host factors, antiviral targets and compounds.

Plasma-Signature-Model for End-Stage Liver Disease Score to Predict Survival in Severe Alcoholic Hepatitis.

BACKGROUND & AIMS: Severe alcoholic hepatitis (AH) is a highly lethal condition and it is still a challenge to predict the outcome. We previously identified and validated a composite score of hepatic 123-gene prognostic signature and the model for end-stage liver disease (MELD) score: gene signature-MELD. However, the need for liver biopsy limits its clinical application. Therefore, we aimed to identify a plasma protein-based surrogate of the gene signature and independently validate its prognostic capability. METHODS: All patients were diagnosed with severe AH at Cliniques universitaires de Bruxelles Hôpital Erasme (Brussels, Belgium), and the plasma samples were collected at admission before any treatment. The primary outcome was death or liver transplantation within 90 days. Using our computational pipeline, named translation of tissue expression to secretome (TexSEC), a hepatic-transcriptome-based prognostic signature was converted to a plasma-based secretome signature, which was optimized in 50 patients by comparing their hepatic molecular dysregulation status and combining it with the MELD score. The composite score was validated independently in 57 patients. RESULTS: The TexSEC and optimization process identified a 6-plasma-protein panel as a surrogate for the 123-gene signature. A composite score with the MELD score, the plasma-signature (ps)-MELD score, was created by using the coefficients of the gene signature-MELD equation. In the validation cohort, the high-risk ps-MELD (n = 23; 40%) was associated significantly with death or liver transplantation within 90 days (adjusted hazard ratio, 4.57; 95% CI, 2.15-9.30; P < .001). The ps-MELD score showed a stable, high prognostic association (time-dependent area under receiver operating characteristics curve, >0.80) and was well calibrated over time; it consistently outperformed existing clinical scores as indicated by various model performance indices. CONCLUSIONS: The high-risk ps-MELD score was associated with short-term survival in patients with severe AH.

A Blood-Based Prognostic Liver Secretome Signature Predicts Long-term Risk of Hepatic Decompensation in Cirrhosis.

Cirrhosis is the terminal stage of progressive liver fibrosis, affecting 1%-2% of the global population and accounting for 1.3 million deaths annually.1,2 Median survival for persons with compensated cirrhosis is approximately 12 years, compared with only 2 years for those with hepatic decompensation. Accurate prediction of hepatic decompensation is an unmet need to enable identification of patients with cirrhosis who could benefit from close monitoring and timely medical interventions. Besides, risk stratification of patients with cirrhosis could help inform patient selection for trials evaluating therapies to prevent hepatic decompensation. Although various clinical scores, such as the albumin-bilirubin (ALBI) and fibrosis-4 (FIB-4) indices (ALBI-FIB4 score) have been proposed to predict long-term risk of hepatic decompensation,3 external validation has often shown suboptimal prognostic capability and revealed room for improvement.4.

Mucosal Congestion on the First Day Following Endoscopy Predicts Anastomotic Stricture After Esophagectomy.

BACKGROUND: Anastomotic stricture is a relatively common postoperative complication after esophagectomy. Previous studies have indicated that impaired perioperative blood perfusion at the anastomosis is associated with the occurrence of stricture. Therefore, we analyzed the association between endoscopically assessed blood perfusion during the early postoperative period and anastomotic stricture. METHODS: This retrospective study evaluated patients who underwent esophagectomy at Tokyo Medical and Dental University between 2010 and 2015. The patients had undergone nasal endoscopy on the 1st and 8th postoperative days. The findings were used to evaluate blood perfusion at the anastomosis and gastric tube, which was classified based on mucosal color as ischemia (white) or congestion (blue or black). Univariate and multivariable logistic regression analyses were performed to identify risk factors for anastomotic stricture. RESULTS: The study included 197 patients and anastomotic stricture was observed in 60 patients (30.4%). The multivariable analysis revealed that postoperative gastric tube congestion was a risk factor for stricture (odds ratio [OR]: 6.440, 95% confidence interval [CI]: 2.660-15.600; p < 0.001). Lower risks of anastomotic stricture were associated with pathological stage III-IV disease (OR: 0.325, 95% CI: 0.161-0.656; p = 0.002). CONCLUSION: This study revealed that endoscopically detected congestion at the anastomosis on the first postoperative day was a risk factor for anastomotic stricture.

Preliminary study for developing a navigation system for gastric cancer surgery using artificial intelligence.

PURPOSE: We are attempting to develop a navigation system for safe and effective peripancreatic lymphadenectomy in gastric cancer surgery. As a preliminary study, we examined whether or not the peripancreatic dissection line could be learned by a machine learning model (MLM). METHODS: Among the 41 patients with gastric cancer who underwent radical gastrectomy between April 2019 and January 2020, we selected 6 in whom the pancreatic contour was relatively easy to trace. The pancreatic contour was annotated by a trainer surgeon in 1242 images captured from the video recordings. The MLM was trained using the annotated images from five of the six patients. The pancreatic contour was then segmented by the trained MLM using images from the remaining patient. The same procedure was repeated for all six combinations. RESULTS: The median maximum intersection over union of each image was 0.708, which was higher than the threshold (0.5). However, the pancreatic contour was misidentified in parts where fatty tissue or thin vessels overlaid the pancreas in some cases. CONCLUSION: The contour of the pancreas could be traced relatively well using the trained MLM. Further investigations and training of the system are needed to develop a practical navigation system.

The impact of lymphadenectomy on lymph node recurrence after performing various treatments for esophageal squamous cell carcinoma.

BACKGROUND: Treatment for regional lymph node recurrence after initial treatment for esophageal squamous cell carcinoma (ESCC) differs among institutions. Though some retrospective cohort studies have shown that lymphadenectomy for cervical lymph node recurrence is safe and leads to long-term survival, the efficacy remains unclear. In this study, we investigated the long-term outcomes of patients who underwent lymphadenectomy for regional recurrence after treatment for ESCC. PATIENTS AND METHODS: We retrieved 20 cases in which lymphadenectomy was performed for lymph node recurrence after initial treatment for ESCC in our hospital from January 2003 to December 2016. Initial treatments included esophagectomy, endoscopic resection (ER) and chemoradiotherapy/chemotherapy (CRT/CT). Overall survival (OS) and recurrence-free survival (RFS) after lymphadenectomy were calculated by the Kaplan-Meier method. We also used a univariate analysis with a Cox proportional hazards model to determine factors influencing the long-term outcomes. RESULTS: The five-year OS and RFS of patients who underwent secondary lymphadenectomy for recurrence after initial treatment were 50.0% and 26.7%, respectively. The five-year overall survival rates of patients who received esophagectomy, ER and CRT/CT as initial treatments, were 40.0%, 75.0% and 50.0%, respectively. The five-year OS rates of patients with Stage I and Stage II-IVB at initial treatments were 83.3% and 33.3%, respectively. CONCLUSIONS: Lymphadenectomy for regional recurrence after initial treatment for ESCC is effective to some degree. Patients with regional recurrence after initial treatment for Stage I ESCC have a good prognosis; thus, lymphadenectomy should be considered for these cases.