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.

Prognostic Factors for Severe-to-Fatal Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis: A Multicenter Prospective Cohort Study.

The prognostic factors associated with severe-to-fatal post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) remain unclear despite the extensive number of studies on PEP. In total, 3739 ERCP patients with biliary disease with an intact papilla and indicated for ERCP were prospectively enrolled at 36 centers from April 2017 to March 2018. Those with acute pancreatitis diagnosed before ERCP, altered gastrointestinal anatomy, and an American Society of Anesthesiologists (ASA) physical status > 4 were excluded. Univariate and multivariate logistic regression analyses were performed on patient-related factors, operator-related factors, procedure-related factors, and preventive measures to identify potential prognostic factors for severe-to-fatal PEP. Multivariate analyses revealed pancreatic guidewire-assisted biliary cannulation (OR 13.59, 95% CI 4.21-43.83, p < 0.001), post-ERCP non-steroidal anti-inflammatory drug (NSAID) administration (OR 11.54, 95% CI 3.83-34.81, p < 0.001), and previous pancreatitis (OR 6.94, 95% CI 1.45-33.33, p = 0.015) as significant risk factors for severe-to-fatal PEP. Preventive measures included endoscopic biliary sphincterotomy (EST; OR 0.29, 95% CI, 0.11-0.79, p = 0.015) and prophylactic pancreatic stents (PPSs; OR 0.11, 95% CI, 0.01-0.87, p = 0.036). In biliary ERCP, pancreatic guidewire-assisted biliary cannulation, NSAID administration after ERCP, and previous pancreatitis were risk factors for severe-to-fatal PEP, whereas EST and PPS were significant preventive measures for severe-to-fatal PEP.

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.

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.

Association of Sarcopenia with a Poor Prognosis and Decreased Tumor-Infiltrating CD8-Positive T Cells in Pancreatic Ductal Adenocarcinoma: A Retrospective Analysis.

BACKGROUND: Sarcopenia, defined as a loss of skeletal muscle mass and quality, is found in 30-65% of patients with pancreatic ductal adenocarcinoma (PDAC) at diagnosis, and is a poor prognostic factor. However, it is yet to be evaluated why sarcopenia is associated with poor prognosis. Therefore, this study elucidated the tumor characteristics of PDAC with sarcopenia, including driver gene alterations and tumor microenvironment. PATIENTS AND METHODS: We retrospectively analyzed 162 patients with PDAC who underwent pancreatic surgery between 2008 and 2017. We defined sarcopenia by measuring the skeletal muscle mass at the L3 level using preoperative computed tomography images and evaluated driver gene alteration (KRAS, TP53, CDKN2A/p16, and SMAD4) and tumor immune (CD4+, CD8+, and FOXP3+) and fibrosis status (stromal collagen). RESULTS: In localized-stage PDAC (stage ≤ IIa), overall survival (OS) and recurrence-free survival were significantly shorter in the sarcopenia group than in the non-sarcopenia group (2-year OS 89.7% versus 59.1%, P = 0.03; 2-year RFS 74.9% versus 50.0%, P = 0.02). Multivariate analysis revealed that sarcopenia was an independent poor prognostic factor in localized-stage PDAC. Additionally, tumor-infiltrating CD8+ T cells in the sarcopenia group were significantly less than in the non-sarcopenia group (P = 0.02). However, no difference was observed in driver gene alteration and fib.rotic status. These findings were not observed in advanced-stage PDAC (stage ≥ IIb). CONCLUSIONS: Sarcopenia was associated with a worse prognosis and decreased tumor-infiltrating CD8+ T cells in localized-stage PDAC. Sarcopenia may worsen a patient's prognosis by suppressing local tumor immunity.

Progression of Recurrent Pancreatitis to Chronic Pancreatitis within 3 Years due to SPINK1 Mutation IVS3+2T>C.

When the etiology of pancreatitis cannot be determined despite sufficient investigation, recurrence and progression to chronic pancreatitis often involve genetic mutations. Herein, we describe a case of recurrent pancreatitis with the IVS3+2T>C mutation in the serine protease inhibitor Kazal type 1 (SPINK1) gene that progressed to chronic pancreatitis in only 3 years. A 35-year-old man was referred to our hospital, where he was diagnosed with mild pancreatitis and was treated conservatively. However, the patient experienced recurrent episodes of pancreatitis, which progressed to become chronic pancreatitis with a pancreatic calcification 1 year later. After 3 years, the patient developed pancreatic duct stenosis and required a pancreatic duct stent placement. Regarding the cause of chronic pancreatitis, alcohol abuse was ruled out based on history taking. Considering the course of treatment, autoimmune pancreatitis and obstructive pancreatitis, such as pancreatic divisum, were also ruled out. Finally, a germline genetic test was performed to determine the etiology of pancreatitis, which revealed the IVS3+2T>C mutation in SPINK1. This case shows the importance of genetic testing in patients with idiopathic pancreatitis to determine their etiology and is a rare incident that can report the progression of the disease from acute to chronic pancreatitis.

Integrated analysis of tertiary lymphoid structures in relation to tumor-infiltrating lymphocytes and patient survival in pancreatic ductal adenocarcinoma.

BACKGROUND: Tertiary lymphoid structure (TLS) reflects an intense immune response against cancer, which correlates with favorable patient survival. However, the association of TLS with tumor-infiltrating lymphocytes (TILs) and clinical outcomes has not been investigated comprehensively in pancreatic ductal adenocarcinoma (PDAC). METHODS: We utilized an integrative molecular pathological epidemiology database on 162 cases with resected PDAC, and examined TLS in relation to levels of TILs, patient survival, and treatment response. In whole-section slides, we assessed the formation of TLS and conducted immunohistochemistry for tumor-infiltrating T cells (CD4, CD8, CD45RO, and FOXP3). As confounding factors, we assessed alterations of four main driver genes (KRAS, TP53, CDKN2A [p16], and SMAD4) using next-generation sequencing and immunohistochemistry, and tumor CD274 (PD-L1) expression assessed by immunohistochemistry. RESULTS: TLSs were found in 112 patients with PDAC (69.1%). TLS was associated with high levels of CD4+ TILs (multivariable odds ratio [OR], 3.50; 95% confidence interval [CI] 1.65-7.80; P = 0.0002), CD8+ TILs (multivariable OR, 11.0; 95% CI 4.57-29.7, P < 0.0001) and CD45RO+ TILs (multivariable OR, 2.65; 95% CI 1.25-5.80, P = 0.01), but not with levels of FOXP3+ TILs. TLS was associated with longer pancreatic cancer-specific survival (multivariable hazard ratio, 0.37; 95% CI 0.25-0.56, P < 0.0001) and favorable outcomes of adjuvant S-1-treatment. TLS was not associated with driver gene alterations but tumor CD274 negative expression. CONCLUSIONS: Our comprehensive data supports the surrogacy of TLS for vigorous anti-tumor immune response characterized by high levels of helper and cytotoxic T cells and their prognostic role.

Lobularity rather than hyperechoic foci/stranding on endoscopic ultrasonography is associated with more severe histological features in chronic pancreatitis.

BACKGROUND AND AIM: Endoscopic ultrasonography (EUS) findings of the pancreatic parenchyma, such as hyperechoic foci/stranding and lobularity, may be associated with the severity of chronic pancreatitis (CP). However, the correlation between parenchymal EUS findings and histology remains unclear. We designed a large-scale retrospective study analyzing over 200 surgical specimens to elucidate the association between parenchymal EUS findings and histological features. METHODS: Clinical data of 221 patients with pancreatobiliary tumors who underwent preoperative EUS and pancreatic surgery between January 2010 and November 2020 were reviewed to investigate the association between parenchymal EUS findings and histological features at the pancreatic body. None of these patients met the definition of CP. RESULTS: Of the 221 patients, 87 (39.4%), 89 (40.2%), and 45 (20.4%) had normal EUS findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity, respectively. In the multivariate analyses, parenchymal EUS findings significantly correlated with histological CP findings of fibrosis, inflammation, and atrophy (hyperechoic foci/stranding without lobularity vs hyperechoic foci/stranding with lobularity, odds ratio [95% confidence interval]: 4.1 [2.2-7.9] vs 31.3 [9.3-105.6], Ptrend  < 0.001; 3.9 [1.9-8.2] vs 21.8 [8.0-59.4], Ptrend  < 0.001; and 4.0 [2.0-7.8] vs 22.9 [7.0-74.5], Ptrend  < 0.001, respectively). Further, a trend toward higher histological grade was observed in the following order: normal findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity. CONCLUSIONS: Endoscopic ultrasonography findings of the pancreatic parenchyma may be associated with the histological conditions in CP, such as pancreatic fibrosis, inflammation, and atrophy. Lobularity reflects more severe histological conditions than does hyperechoic foci/stranding.

Computed tomography imaging-based predictors of the need for a step-up approach after initial endoscopic ultrasound-guided transmural drainage for pancreatic fluid collections.

BACKGROUND: A step-up approach is recommended as a new treatment algorithm for pancreatic fluid collections (PFCs). However, determining which patients with PFCs require a step-up approach after endoscopic ultrasound-guided transmural drainage (EUS-TD) is unclear. If the need for a step-up approach could be predicted, it could be performed early for relevant patients. We aimed to identify PFC-related predictive factors for a step-up approach after EUS-TD. METHODS: This retrospective cohort study included consecutive patients who had undergone EUS-TD for PFCs from January 2008 to May 2020. Multivariable logistic regression analyses were performed to investigate PFC factors related to requiring a step-up approach. A step-up approach was performed for patients who did not respond clinically to EUS-TD. RESULTS: We enrolled 81 patients, of whom 25 (30.9%) required a step-up approach. In multivariate logistic regression analysis, the pre-EUS-TD number of PFC-occupied regions ≥ 3 (multivariate odds ratio [OR] 16.2, 95% confidence interval [CI] 2.68-97.6, P = 0.002), the post-EUS-TD PFC-remaining percentage ≥ 35% (multivariate OR 19.9, 95% CI 2.91-136.1, P = 0.002), and a positive sponge sign, which is a distinctive computed tomography finding in the early stage after EUS-TD (multivariate OR 6.26, 95% CI 1.33-29.3, P = 0.020), were independent predictive factors associated with requiring a step-up approach for PFCs. CONCLUSION: Pre-EUS-TD PFC-occupied regions, post-EUS-TD PFC-remaining percentage, and a positive sponge sign were predictors of the need for a step-up approach. Patients with PFC with these findings should be offered a step-up approach whereas conservative treatment is recommended for patients without these findings. CLINICAL REGISTRATION NUMBER: UMIN 000030898.

Delayed immune-related sclerosing cholangitis after discontinuation of pembrolizumab: A case report.

BACKGROUND: Secondary sclerosing cholangitis, characterized by biliary obstruction, can be caused by drugs such as immune checkpoint inhibitors (ICIs). While there a few reports of sclerosing cholangitis after immune checkpoint inhibitor administration, no case has been reported after discontinuation of such drugs. CASE SUMMARY: A 68-year-old man who underwent chemotherapy for lung adenocarcinoma with bone metastasis presented with abdominal pain and fever 4 mo after the final administration of pembrolizumab. Computed tomography revealed thickening of the gallbladder wall and dilatation of the common bile duct. Endoscopic retro-grade cholangiopancreatography revealed an irregularly narrowed intrahepatic bile duct. Biopsy of the bile duct demonstrated that CD8+ T cells were predominant over CD4+ T cells. Liver biopsy showed dominant infiltration of CD8+ T in the portal tract, but onion-skin lesions were not observed. The patient was diagnosed with immune-related sclerosing cholangitis induced by pembrolizumab. Administration of methylprednisolone and endoscopic nasobiliary drainage were performed, but the cholangiography and laboratory test findings did not improve. No further treatment was administered due to disease progression, and the patient was referred for palliative care. CONCLUSION: Immune-related sclerosing cholangitis may have a late onset, and such cases occurring after discontinuation of ICIs should be carefully managed.

Advantage of endoscopic papillectomy for ampullary tumors as an alternative treatment for pancreatoduodenectomy.

Endoscopic papillectomy for early ampullary tumors is considered a minimally invasive and useful alternative to pancreatoduodenectomy; however, its indications remain unclear. This study aimed to clarify the advantages of endoscopic papillectomy by investigating the clinical outcomes of patients who underwent endoscopic papillectomy or pancreatoduodenectomy for early ampullary tumors. Patients diagnosed with early ampullary tumors (adenoma, Tis, T1a) who underwent endoscopic papillectomy or pancreatoduodenectomy between June 2008 and October 2019 were included, and their clinical outcomes were analyzed. Seventy-four patients (34 patients with adenomas and 40 patients with adenocarcinomas) were divided into two groups, namely endoscopic papillectomy (n = 43) and pancreatoduodenectomy (n = 31). The estimated 5-year overall survival rate of all early ampullary tumors was 92%. Complete resection rate was significantly lower for endoscopic papillectomy patients versus pancreatoduodenectomy patients (48.8% vs. 100%; p < 0.001). Recurrence was more common in the endoscopic papillectomy group compared to the pancreatoduodenectomy group (16.3% vs. 3.2%; p = 0.128), but all recurrences were controllable by endoscopic treatment. The median length of hospital stay for the endoscopic papillectomy group was significantly shorter compared to the endoscopic papillectomy group (11 days vs. 42 days; p < 0.001). The Comprehensive Complication Index was significantly lower in the endoscopic papillectomy group compared to the pancreatoduodenectomy group (14.8 vs 22.6%; p = 0.002). Endoscopic papillectomy for early ampullary tumors is useful and may be an alternative treatment for pancreatoduodenectomy in selected cases.

Comprehensive Analysis of Molecular Biologic Characteristics of Pancreatic Ductal Adenocarcinoma Concomitant with Intraductal Papillary Mucinous Neoplasm.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN) is defined as PDAC occurring apart from IPMN. This study comprehensively investigated the molecular biologic characteristics of PDAC concomitant with IPMN in major genetic alterations, tumor microenvironment, and prognosis by contrast with those of conventional PDAC. METHODS: The study retrospectively reviewed the data of 158 surgically resected PDAC patients. The driver gene alteration status (KRAS, TP53, CDKN2A, SMAD4, and GNAS) together with the immune and fibrotic status in tumor was evaluated. The prognosis of PDAC concomitant with IPMN and that of conventional PDAC also were compared. RESULTS: No statistically significant difference was found between PDAC concomitant with IPMN and conventional PDAC in the alteration frequency analysis of the major driver genes and the immune and fibrotic status in the tumor microenvironment. Overall survival and disease-free survival between patients who had PDAC concomitant with IPMN and those who had conventional PDAC did not show statistically significant differences in propensity-matched subjects. Furthermore, the co-existence of IPMN was not a poor prognostic factor in the multivariable-adjusted Cox proportional hazards model (hazard ratio, 0.95; 95 % confidence interval, 0.51-1.78). CONCLUSIONS: In this study, PDAC concomitant with IPMN had tumor characteristics similar to those of conventional PDAC in terms of the major driver gene alterations, tumor microenvironment, and prognosis.

Acute pancreatitis in intraductal papillary mucinous neoplasms correlates with pancreatic volume and epithelial subtypes.

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is associated with acute pancreatitis (AP) in some cases, however its causes have not been fully elucidated. We investigated the association of the incidence of AP with epithelial subtypes and pancreatic volume in IPMN. METHODS: This retrospective study included 182 consecutive surgically resected IPMN patients between January 2000 and December 2018. The relationship between the incidence of AP and epithelial subtypes of IPMN and pancreatic volume was investigated. Epithelial subtypes of IPMN were classified into gastric (G type: N = 116), intestinal (I type: N = 49), pancreatobiliary (PB type: N = 14), and oncocytic types (O type: N = 3). Pancreatic volume of the contrast-enhanced computed tomography scan was measured using Ziostation2 software. Histological pancreatic parenchymal atrophy was also evaluated. RESULTS: AP occurred more frequently in I-types (I-type vs. G-type, 22.4% [11/49] vs 3.4% [4/116], P = 0.003) and PB-types (PB type vs. G-type, 35.7% [5/14] vs. 3.4% [4/116], P = 0.007) in comparison with G-types, which constituted the majority of the resected IPMNs. AP occurred more frequently in I-type patients with high pancreatic volumes (I-type with high pancreatic volume vs. I-type with low pancreatic volume, 37.0% [10/27] vs. 4.7% [1/21], P = 0.02). However, histological atrophy did not show an additional influence on the association between the incidence of AP and epithelial subtypes. The elevation of serum pancreatic enzymes was not significantly related to epithelial subtypes. CONCLUSION: Epithelial subtypes and the degree of pancreatic volume may be closely associated with the incidence of AP in IPMN.

A case of high-grade pancreatic intraepithelial neoplasia diagnosed based on focal pancreatic parenchymal atrophy after acute pancreatitis.

A 60-year-old male visited a previous hospital with upper abdominal pain. He was diagnosed with localized mild acute pancreatitis. Three months later, abdominal contrast-enhanced computed tomography showed focal parenchymal atrophy of the pancreas with distal pancreatic duct dilation. No obvious solid mass could be found at the site of the pancreatic duct stenosis on imaging examinations. Endoscopic retrograde pancreatography showed focal mild stenosis with distal pancreatic duct dilation in the tail of the pancreas. Carcinoma in situ of the pancreas was strongly suspected, especially based on the presence of focal atrophy of the pancreas around the site of stenosis of the main pancreatic duct and the distal pancreatic duct dilation. Laparoscopic distal pancreatectomy was performed. Histologically, high-grade pancreatic intraepithelial neoplasia was found in the epithelium of the stenotic main pancreatic duct and its branches. This case suggests that localized acute pancreatitis and focal atrophy of the pancreas with distal dilation of the pancreatic duct could be important clinical manifestations of pancreatic carcinoma in situ.