Rim Enhancement on Contrast-Enhanced CT as a Predictor of Prognosis in Patients with Pancreatic Ductal Adenocarcinoma.

This study investigated the utility of imaging features, such as rim enhancement on contrast-enhanced CT (CECT), in predicting the prognosis of pancreatic ductal adenocarcinoma (PDAC). This retrospective study included 158 patients (84 men; mean age, 68 years) with pathologically confirmed PDAC. The following imaging features were evaluated on CECT by two radiologists: tumor size, tumor attenuation, and the presence of rim enhancement. Cox proportional hazards analysis was performed to identify the imaging and clinicopathological features for predicting disease-free survival (DFS) and overall survival (OS). Pathological features were compared with the presence of rim enhancement. Among the 158 patients, 106 (67%) underwent curative surgery (surgery group) and 52 (33%) received conservative treatment (non-surgery group). Rim enhancement was observed more frequently in the non-surgery group than in the surgery group (44% vs. 20%; p < 0.001). Rim enhancement showed significant associations with shorter DFS and OS in the surgery group (hazard ratios (HRs), 3.03 and 2.99; p < 0.001 and p = 0.003, respectively), whereas tumor size showed significant associations with shorter OS (HR per 1 mm increase, 1.08; p < 0.001). PDACs with rim enhancement showed significant associations with higher histological tumor grades (p < 0.001). PDAC with rim enhancement on CECT could predict poorer prognosis and more aggressive tumor grades.

Role of Wnt5b-Ror1 signaling in the proliferation of pancreatic ductal adenocarcinoma cells.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most refractory cancers with the worst prognosis. Although several molecules are known to be associated with the progression of PDAC, the molecular mechanisms underlying the progression of PDAC remain largely elusive. The Ror-family receptors, Ror1 and Ror2, which act as a receptor(s) for Wnt-family ligands, particularly Wnt5a, are involved in the progression of various types of cancers. Here, we show that higher expression of Ror1 and Wnt5b, but not Ror2, are associated with poorer prognosis of PDAC patients, and that Ror1 and Wnt5b are expressed highly in a type of PDAC cell lines, PANC-1 cells. Knockdown of either Ror1 or Wnt5b in PANC-1 cells inhibited their proliferation significantly in vitro, and knockout of Ror1 in PANC-1 cells resulted in a significant inhibition of tumor growth in vivo. Furthermore, we show that Wnt5b-Ror1 signaling in PANC-1 cells promotes their proliferation in a cell-autonomous manner by modulating our experimental setting in vitro. Collectively, these findings indicate that Wnt5b-Ror1 signaling might play an important role in the progression of some if not all of PDAC by promoting proliferation.

Temporal progression of pancreatic cancer computed tomography findings until diagnosis: A large-scale multicenter study.

BACKGROUND: Focal parenchymal atrophy and main pancreatic duct (MPD) dilatation have been identified as early signs of pancreatic ductal adenocarcinoma. However, limited evidence exists regarding their temporal progression due to previous study limitations with restricted case numbers. OBJECTIVE: To ascertain a more precise frequency assessment of suspicious pancreatic ductal adenocarcinoma findings as well as delineate the temporal progression of them. METHODS: A multicenter retrospective study was conducted on patients diagnosed with pancreatic ductal adenocarcinoma between 2015 and 2021. We included patients who had undergone at least one computed tomography (CT) scan ≥6 months before diagnosing pancreatic ductal adenocarcinoma. The temporal progression of suspicious pancreatic ductal adenocarcinoma findings on CT was investigated. RESULTS: Out of 1832 patients diagnosed with pancreatic ductal adenocarcinoma, 320 had a previous CT before their diagnosis. Suspicious pancreatic ductal adenocarcinoma findings were detected in 153 cases (47.8%), with focal parenchymal atrophy (26.6%) being the most common followed by MPD dilatation (11.3%). Focal parenchymal atrophy was the earliest detectable sign among all suspicious findings and became visible on average 2.7 years before diagnosis, and the next most common, MPD dilatation, 1.1 years before diagnosis. Other findings, such as retention cysts, were less frequent and appeared around 1 year before diagnosis. Focal parenchymal atrophy followed by MPD dilatation was observed in 10 patients but not in reverse order. Focal parenchymal atrophy was more frequently detected in the pancreatic body/tail. No significant relationship was found between the pathological pancreatic ductal adenocarcinoma differentiation or tumor stage and the time course of the CT findings. All cases of focal parenchymal atrophy progressed just prior to diagnosis, and the atrophic area was occupied by tumor at diagnosis. Main pancreatic duct dilatation continued to progress until diagnosis. CONCLUSION: This large-scale study revealed that the temporal progression of focal parenchymal atrophy is the earliest detectable sign indicating pancreatic ductal adenocarcinoma. These results provide crucial insights for early pancreatic ductal adenocarcinoma detection.

Relapse and side effects of steroid therapy beyond 3 years in autoimmune pancreatitis: A multicenter retrospective study.

BACKGROUND: The impact of extended steroid administration on patients with autoimmune pancreatitis after a 3-year maintenance period remains poorly understood. This study analyzed the advantage and disadvantage of continuing steroid therapy beyond 3 years. METHODS: In this retrospective multicenter study across 17 institutions, patients who successfully completed 3 years of maintenance therapy without experiencing relapse were categorized into two groups: the maintenance therapy discontinuation group, who discontinued steroid therapy after the initial 3-year period, and maintenance therapy continuation group, who continued steroid therapy beyond 3 years. The cumulative relapse rate after 3 years of maintenance therapy was the primary outcome. Relapse predictors were compared using the Gray test for cumulative relapse incidence by specific factor. RESULTS: Of 211 patients, 105 experienced no relapse during the 3-year maintenance therapy and were divided into two groups: 69 in the maintenance therapy discontinuation group and 36 in the maintenance therapy continuation group. The relapse rate was lower in the maintenance therapy continuation group than in the maintenance therapy discontinuation group (P = 0.035). Predictors of relapse after 3 years included cessation of maintenance therapy (hazard ratio [HR] = 3.76; 95 % confidence interval [CI] = 1.07-13.3, P = 0.040) and renal involvement (HR = 2.88; 95 % CI = 1.04-7.99, P = 0.042). The maintenance therapy continuation group showed a significantly higher prevalence of macrovascular complications, compared with the maintenance therapy discontinuation group (P = 0.005). CONCLUSIONS: Cessation of steroid maintenance therapy and renal involvement were predictors of relapse after 3 years of maintenance therapy. However, the long-term use of steroids may increase the risk of macrovascular complications.

Pancreatic injury in patients treated with immune checkpoint inhibitors: a retrospective multicenterstudy.

BACKGROUND: Immune checkpoint inhibitor-related pancreatic injury (ICI-PI) is a rare occurrence, which has not been reported in detail. We conducted a retrospective multicenter study to determine the clinical characteristics, risk factors, and treatment of ICI-PI. METHODS: We reviewed the medical records of patients who received ICIs for malignant tumors between April 2014 and April 2019 at 16 participating hospitals. Patients with elevated pancreatic enzymes or pancreatitis were identified and classified using the Common terminology Criteria for Adverse Events (CTCAE) ver.5.0). The number of patients with pancreatic enzyme elevation was determined and those with pancreatic enzyme elevation of ≥ grade 3 according to CTCAE ver.5.0, or pancreatitis underwent detailed analysis for ICI-PI. RESULTS: The study enrolled 1069 patients. Nineteen patients (1.8%) had ICI-PI, 5 (0.5%) of whom also had pancreatitis. Four patients had mild pancreatitis, whereas 1 patient had severe pancreatitis, culminating in death. Steroid therapy was administered to 7 of 19 patients, which led to ICI-PI improvement in 5 patients. On the other hand, ICI-PI improved in 9 of 12 patients who were not administered steroid therapy. Six of the 14 patients with ICI-PI improvement were rechallenged with ICI, and ICI-PI relapse occurred in only 1 patient (16.7%), which improved with ICI discontinuation and steroid therapy. CONCLUSIONS: ICI-PI is a rare occurrence, with a low incidence of pancreatitis, which followed a very serious course in one patient. Although the benefit of steroid therapy for ICI-PI is unclear, ICI rechallenge is acceptable after improvement of ICI-PI without pancreatitis.

Risk of recurrence with or without plastic stent after EUS-guided treatment of peripancreatic fluid collections: A systematic review and meta-analysis.

Background and study aims Recent advances in endoscopic transmural treatment have improved the clinical outcomes of patients with pancreatic fluid collections (PFCs). However, there is still a debate about the preventive effect of long-term placement of a transmural plastic stent (PS) on recurrence after successful endoscopic ultrasound (EUS)-guided treatment of PFCs. We conducted a systematic review and meta-analysis to evaluate PFC recurrence rates with and without a transmural PS after EUS-guided treatment. Patients and methods A systematic literature search of PubMed, Embase, and the Cochrane database was conducted to identify clinical studies comparing outcomes with and without transmural PS published until September 2022. Data on PFC recurrence and adverse events (AEs) were pooled using a random-effects model. Results Nine studies including 380 patients with long-term transmural PS and 289 patients without PS were identified. The rate of PFC recurrence was significantly lower in patients with transmural PS (pooled odds ratio [OR] = 0.23, 95% confidence interval [CI] [0.08-0.65], P = 0.005). In a subgroup analysis limited to studies focusing on patients with disconnected pancreatic duct syndrome, which has been reported to be a risk factor for PFC recurrence, the OR was numerically lower than that for the entire cohort (OR = 0.14, 95% CI [0.04-0.46]). The rate of AEs was significantly higher with long-term transmural PS (OR = 14.77, 95% CI [4.21-51.83]). Conclusions In this meta-analysis, long-term PS placement reduced the risk of PFC recurrence. Given the potential AEs of indwelling PS, further research is required to evaluate the overall benefits of long-term PS placement.

Impact of intratumoral microbiome on tumor immunity and prognosis in human pancreatic ductal adenocarcinoma.

BACKGROUND: Recent evidence suggests that the presence of microbiome within human pancreatic ductal adenocarcinoma (PDAC) tissue potentially influences cancer progression and prognosis. However, the significance of tumor-resident microbiome remains unclear. We aimed to elucidate the impact of intratumoral bacteria on the pathophysiology and prognosis of human PDAC. METHODS: The presence of intratumoral bacteria was assessed in 162 surgically resected PDACs using quantitative polymerase chain reaction (qPCR) and in situ hybridization (ISH) targeting 16S rRNA. The intratumoral microbiome was explored by 16S metagenome sequencing using DNA extracted from formalin-fixed paraffin-embedded tissues. The profile of intratumoral bacteria was compared with clinical information, pathological findings including tumor-infiltrating T cells, tumor-associated macrophage, fibrosis, and alterations in four main driver genes (KRAS, TP53, CDKN2A/p16, SMAD4) in tumor genomes. RESULTS: The presence of intratumoral bacteria was confirmed in 52 tumors (32%) using both qPCR and ISH. The 16S metagenome sequencing revealed characteristic bacterial profiles within these tumors, including phyla such as Proteobacteria and Firmicutes. Comparison of bacterial profiles between cases with good and poor prognosis revealed a significant positive correlation between a shorter survival time and the presence of anaerobic bacteria such as Bacteroides, Lactobacillus, and Peptoniphilus. The abundance of these bacteria was correlated with a decrease in the number of tumor-infiltrating T cells positive for CD4, CD8, and CD45RO. CONCLUSIONS: Intratumoral infection of anaerobic bacteria such as Bacteroides, Lactobacillus, and Peptoniphilus is correlated with the suppressed anti-PDAC immunity and poor prognosis.

Metabolic Syndrome Accelerates the Age-Related Increase of Intraductal Papillary Mucinous Neoplasm of the Pancreas.

OBJECTIVES: Aging is associated with a high prevalence of pancreatic cysts and intraductal papillary mucinous neoplasms (IPMNs). Metabolic syndrome (MS) may increase the risk of neoplasms, including those that develop in the pancreas. However, the influence of factors associated with MS on the development of IPMN remains unclear. METHODS: A total of 9363 patients who underwent abdominal ultrasound examinations between April 2012 and May 2013 were included in this study. Multivariate logistic regression analysis was performed to identify factors associated with the presence of IPMN by age. RESULTS: Pancreatic cysts were detected in 198 of 9363 patients, of whom 129 were found to have IPMNs. The presence of IPMN significantly correlated with age (10-year increments; odds ratio, 2.73; 95% CI, 2.28-3.29; P < 0.001). High body mass index, history of smoking, hyperlipidemia, hypertension, and MS were associated with a higher prevalence of IPMN with advancing age. In multivariate analysis, the presence of IPMN was more frequent in elderly patients with MS (odds ratio, 3.14; 95% CI, 3.14-6.72; P = 0.003). CONCLUSIONS: The present study suggests that the incidence of IPMN increases with age and is accelerated in the presence of MS.

Factors Associated with Overlap between Functional Dyspepsia and Nonerosive Reflux Disease in Endoscopy-based Helicobacter pylori-uninfected Japanese Health Checkup Participants: A Prospective, Multicenter Cross-sectional Study.

Objective We assessed the factors associated with overlap between functional dyspepsia (FD) and nonerosive reflux disease (NERD) in endoscopy-based Helicobacter pylori-uninfected Japanese health checkup participants. Methods We utilized baseline data from 3,085 individuals who underwent upper endoscopy for health screening in a prospective, multicenter cohort study. The participants were asked to complete a questionnaire detailing their upper abdominal symptoms and lifestyle. Anxiety was assessed using the State-Trait Anxiety Inventory (STAI) score. FD, postprandial distress syndrome (PDS), and epigastric pain syndrome (EPS) were defined according to the Rome III criteria. NERD was defined as heartburn or regurgitation ≥1 day/week without erosive esophagitis. Results Of the 3,085 participants, 73 (2.4%), 97 (3.1%), and 84 (2.7%) had FD alone, NERD alone, and FD-NERD overlap, respectively. Factors associated with FD-NERD-overlap participants compared with participants with neither FD nor NERD were women [odds ratio (OR): 2.08, 95% confidence interval (CI): 1.24-3.52], body mass index (BMI) <18.5 (OR: 2.87, 95% CI: 1.56-5.07), alcohol consumption ≥20 g/day (OR: 1.85, 95% CI: 1.06-3.15), and a high STAI score (OR: 2.53, 95% CI: 1.62-4.00). Increasing age (OR: 1.06, 95% CI: 1.01-1.11) and EPS symptoms [pure EPS (OR: 3.67, 95% CI: 1.65-8.51) and PDS-EPS overlap (OR: 11.6, 95% CI: 4.09-37.2)] were associated with FD-NERD overlap vs. FD alone. Women (OR: 3.17, 95% CI: 1.47-7.04), BMI <18.5 (OR: 3.03, 95% CI: 1.04-9.90), and acid reflux symptoms ≥2 days a week (OR: 3.57, 95% CI: 1.83-7.14) were associated with FD-NERD overlap vs. NERD alone. Conclusion Understanding the clinical features of overlap between FD and NERD will lead to better management.

ERCP using balloon-assisted endoscopes versus EUS-guided treatment for common bile duct stones in Roux-en-Y gastrectomy.

BACKGROUND AND AIMS: We compared ERCP using a balloon-assisted endoscope (BE-ERCP) with EUS-guided antegrade treatment (EUS-AG) for removal of common bile duct (CBD) stones in patients with Roux-en-Y (R-Y) gastrectomy. METHODS: Consecutive patients who had previous R-Y gastrectomy undergoing BE-ERCP or EUS-AG for CBD stones in 16 centers were retrospectively analyzed. RESULTS: BE-ERCP and EUS-AG were performed in 588 and 59 patients, respectively. Baseline characteristics were similar, except for CBD diameter and angle. The technical success rate was 83.7% versus 83.1% (P = .956), complete stone removal rate was 78.1% versus 67.8% (P = .102), and early adverse event rate was 10.2% versus 18.6% (P = .076) in BE-ERCP and EUS-AG, respectively. The mean number of endoscopic sessions was smaller in BE-ERCP (1.5 ± .8 vs 1.9 ± 1.0 sessions, P = .01), whereas the median total treatment time was longer (90 vs 61.5 minutes, P = .001). Among patients with biliary access, the complete stone removal rate was significantly higher in BE-ERCP (93.3% vs 81.6%, P = .009). Negative predictive factors were CBD diameter ≥15 mm (odds ratio [OR], .41) and an angle of CBD <90 degrees (OR, .39) in BE-ERCP and a stone size ≥10 mm (OR, .07) and an angle of CBD <90 degrees (OR, .07) in EUS-AG. The 1-year recurrence rate was 8.3% in both groups. CONCLUSIONS: Effectiveness and safety of BE-ERCP and EUS-AG were comparable in CBD stone removal for patients after R-Y gastrectomy, but complete stone removal after technical success was superior in BE-ERCP.

Early versus delayed EUS-guided drainage for postoperative pancreatic fluid collections: a systematic review and meta-analysis.

BACKGROUND: Postoperative pancreatic fluid collections (POPFCs) are common adverse events (AEs) after pancreatic surgery and may need interventions. Endoscopic ultrasound (EUS)-guided drainage for POPFCs is increasingly reported, but its appropriate timing has not been fully elucidated. The aim of this meta-analysis was to evaluate treatment outcomes of POPFCs according to the timing of EUS-guided drainage. METHODS: Using PubMed, Embase, Web of Science, and the Cochrane database, we identified clinical studies published until December 2022 with data comparing outcomes of early and delayed EUS-guided drainage for POPFCs. We pooled data on AEs, mortality, and technical and clinical success rates, using the random-effects model. RESULTS: From 1415 papers identified in the initial literature search, we identified 6 retrospective studies, including 128 and 107 patients undergoing early and delayed EUS-guided drainage for POPFCs. The threshold of early and delayed drainage ranged from 14 to 30 days. Distal pancreatectomy was the major cause of POPFCs, ranging from 44 to 100%. The pooled odds ratio (OR) for AEs was 0.81 (95% confidence interval [CI] 0.40-1.64, P = 0.55) comparing early to delayed drainage. There was no procedure-related mortality. Technical success was achieved in all cases and a pooled OR of clinical success was 0.60 (95% CI 0.20-1.83, P = 0.37). CONCLUSION: POPFCs can be managed by early EUS-guided drainage without an increase in AEs.

Adverse events of self-expandable metal stent placement for malignant distal biliary obstruction: a large multicenter study.

BACKGROUND AND AIMS: Endoscopic placement of self-expandable metal stents (SEMSs) for malignant distal biliary obstruction (MDBO) may be accompanied by several types of adverse events. The present study analyzed the adverse events occurring after SEMS placement for MDBO. METHODS: The present study retrospectively investigated the incidence and types of adverse events in patients who underwent SEMS placement for MDBO between April 2018 and March 2021 at 26 hospitals. Risk factors for acute pancreatitis, cholecystitis, and recurrent biliary obstruction (RBO) were evaluated by univariate and multivariate analyses. RESULTS: Of the 1425 patients implanted with SEMSs for MDBO, 228 (16.0%) and 393 (27.6%) experienced early adverse events and RBO, respectively. Pancreatic duct without tumor involvement (P = .023), intact papilla (P = .025), and SEMS placement across the papilla (P = .037) were independent risk factors for acute pancreatitis. Tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis (P < .001). Use of fully and partially covered SEMSs was an independent risk factor for food impaction and/or sludge. Use of fully covered SEMSs was an independent risk factor for stent migration. Use of uncovered SEMSs and laser-cut SEMSs was an independent risk factor for tumor ingrowth. CONCLUSIONS: Pancreatic duct without tumor involvement, intact papilla, and SEMS placement across the papilla were independent risk factors for acute pancreatitis, and tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis. The risk factors for food impaction and/or sludge, stent migration, and tumor ingrowth differed among types of SEMSs.

Use of Peroral Pancreatoscopy in the Diagnosis of Elusive Intraductal Papillary Mucinous Neoplasm With High-Grade Dysplasia.

Intraductal papillary mucinous neoplasm (IPMN) is a premalignant lesion of the pancreas that can occasionally manifest as recurrent acute pancreatitis. In this report, we discuss a unique case of a 49-year-old woman who presented with recurrent acute pancreatitis of an unknown cause for several years. Workup using peroral pancreatoscopy eventually showed main-duct IPMN with high-grade dysplasia as the obscure cause of recurrent acute pancreatitis. This case report highlights the clinical course of main-duct IPMN and the evolving role of peroral pancreatoscopy in patients with recurrent acute pancreatitis.

Risk factors for adverse outcomes at various phases of endoscopic ultrasound-guided treatment of pancreatic fluid collections: Data from a multi-institutional consortium.

OBJECTIVES: No comprehensive study has examined short- and long-term adverse outcomes of endoscopic ultrasound (EUS)-guided treatment of pancreatic fluid collections (PFCs) including walled-off necrosis (WON) and pseudocysts. METHODS: In a multi-institutional cohort of 357 patients receiving EUS-guided treatment of PFCs (228 with WON and 129 with pseudocysts), we examined PFC type-specific risk factors for procedure-related adverse events (AEs), clinical failure, and recurrence. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using the logistic and Cox regression models, respectively, adjusting for potential confounders. RESULTS: Adverse events were observed predominantly in WON, and risk factors were WON extension to the pelvis (OR 2.49; 95% CI 1.00-6.19) and endoscopic necrosectomy (OR 5.15; 95% CI 1.61-16.5). Risk factors for clinical failure in WON treatment included higher Charlson Comorbidity Index (OR for ≥3 vs. ≤2, 2.58; 95% CI 1.05-6.35), extension to the pelvis (OR 3.63; 95% CI 1.57-8.43), nonuse of a lumen-apposing metal stent (OR 2.88; 95% CI 1.10-7.54), and percutaneous drainage (OR 3.73; 95% CI 1.27-10.9). Patients with pseudocysts extending to the paracolic gutter and the need for more than two endoscopic/percutaneous procedures had ORs for clinical failure of 5.28 (95% CI 1.10-25.3) and 5.52 (95% CI 1.61-18.9), respectively. Pseudocysts requiring the multigateway approach were associated with a high risk of recurrence (HR 4.00; 95% CI 1.11-11.6). CONCLUSION: The adverse outcomes at various phases of EUS-guided PFC treatment may be predictable based on clinical parameters. Further research is warranted to optimize treatment strategies for high-risk patients.

A comprehensive analysis of tumor-stromal collagen in relation to pathological, molecular, and immune characteristics and patient survival in pancreatic ductal adenocarcinoma.

BACKGROUND: Abundant collagen deposition is a hallmark of pancreatic ductal adenocarcinomas (PDACs). This study clarified the interactive relationship between tumor-stromal collagen, molecular and immune characteristics, and tumor pr ogression in human PDAC. METHODS: We performed a comprehensive examination using an integrative molecular pathological epidemiology database on 169 cases with resected PDAC . The amount of tumor-stromal collagen was quantified through digital imaging analysis for Elastica van Gieson-stained whole-section tumor slides. We analyzed the association of tumor-stromal collagen with gene alterations (KRAS, TP53, CDKN2A/p16, and SMAD4), immune parameters (CD4+ tumor-infiltrating lymphocytes [TILs], CD8+ TILs, FOXP3+ TILs, and tertiary lymphoid structures), and patient prognosis. RESULTS: Low amounts of tumor-stromal collagen were associated with poor differentiation (multivariable OR = 3.82, 95%CI = 1.41-12.2, P = 0.008) and CDKN2A/p16 alteration (OR [95%CI] = 2.06 [1.08-4.02], P = 0.03). Tumors with low collagen levels had shorter overall survival (HR [95%CI] = 2.38 [1.59-3.56], P < 0.0001). In the S-1 and gemcitabine (GEM) treatment groups, low tumor-stromal collagen was linked to poor prognosis of patients with PDAC (S-1 group: multivariable HR [95%CI] = 2.76 [1.36-5.79], P = 0.005; GEM group: multivariate HR [95%CI] = 2.91 [1.34-6.71], P = 0.007). Additionally, low amounts of tumor-stromal collagen were also linked to low levels of CD4+ TILs (P = 0.046), CD8+ TILs (P = 0.09), and tertiary lymphoid structures (P = 0.001). CONCLUSIONS: Tumor-stromal collagen deposition may play a crucial role in modulating tumor-immune microenvironment and determining response to adjuvant chemotherapy and patient survival outcomes.

Benefits of pancreatic parenchymal endoscopic ultrasonography in predicting microscopic precancerous lesions of pancreatic cancer.

Pancreatic cancer primarily arises from microscopic precancerous lesions, such as pancreatic intraepithelial neoplasia (PanIN) and acinar-to-ductal metaplasia (ADM). However, no established method exists for predicting pancreatic precancerous conditions. Endoscopic ultrasonography (EUS) can detect changes in pancreatic parenchymal histology, including fibrosis. This study aimed to elucidate the relationship between pancreatic parenchymal EUS findings and microscopic precancerous lesions. We retrospectively analyzed 114 patients with pancreatobiliary tumors resected between 2010 and 2020 and evaluated the association between pancreatic parenchymal EUS findings and the number of PanIN, ADM, and pancreatic duct gland (PDG). Of the 114 patients, 33 (29.0%), 55 (48.2%), and 26 (22.8%) had normal EUS findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity, respectively. Multivariate analyses revealed that abnormal EUS findings were significantly associated with the frequency of PanIN (hyperechoic foci/stranding without lobularity: OR [95% CI] = 2.7 [1.0-7.3], with lobularity: 6.5 [1.9-22.5], Ptrend = 0.01) and ADM (hyperechoic foci/stranding without lobularity: 3.1 [1.1-8.2], with lobularity: 9.7 [2.6-36.3], Ptrend = 0.003) but not with PDG (hyperechoic foci/stranding without lobularity: 2.2 [0.8-5.8], with lobularity: 3.2 [1.0-10.2], Ptrend = 0.12). We observed a trend toward a significantly higher number of precancerous lesions in the following order: normal findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity. Pancreatic parenchymal EUS findings were associated with the increased frequency of PanIN and ADM. Lobularity may help predict the increased number of precancerous lesions.

A novel fully covered metal stent for unresectable malignant distal biliary obstruction: results of a multicenter prospective study.

Background/Aims: Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO. Methods: This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events. Results: A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration. Conclusions: The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration.