High-grade Intraductal Papillary Mucinous Neoplasms Research Articles

Abstract 1588: Identification of new signaling pathways between fibroblasts & tumor cells in pancreatic cancer

Abstract We explore the unstudied role of nanoparticles (NPs), recently discovered secreted non-vesicular nanoparticles, in signaling between pre-cancer associated fibroblasts (preCAF), CAFs, and tumor cells. We generated two novel primary lines preCAF PFUM1 from a patient with high-grade intraductal papillary mucinous neoplasms and CAF FUM2 from a patient with pancreatic ductal adenocarcinoma, all tests performed between passages 2 and 3, fibroblast purity validated by RT-PCR and ACTA2 immunofluorescence. Small extracellular vesicles (sEVs), exomeres, and supermeres (the two main forms of NPs) were isolated by the ultracentrifugation method from PF-UM1 and F-UM2 with n=2-3 experiments. To validate the isolation, we used nanoparticle tracking, electron, and fluid-phase atomic force microscopy. Proteins were quantified by BCA assay. Liquid chromatography-mass spectrometry characterized the cargo from each fraction. Human cancer lines MIAPACA2 and SU8686 were treated with 10 μg of each fraction and cell proliferation was tested by phase-contrast images (Cytation 5), analyzed by Ilastik-based 1.4.0 machine-learning. We performed fluorescent Ki-67 and vimentin staining and quantified in QuPath 0.4.3. Non-parametric statistics were performed in Prism GraphPad. NPs constitute the major fraction of small particles released by fibroblasts, containing 80.5% (PFUM1) and 77.5% (FUM2) of the protein load by quantification. Mass spectrometry reveals enrichment of growth factors, epithelial-to-mesenchymal (EMT) transition, and metabolism-associated proteins in the NPs compared to sEVs. At 72 hours, cell proliferation for Su8686 reveals a proliferative effect for all fractions from both PFUM1 and FUM2 (19-63% increase compared to controls, p=0.049 to <0.0001). For MIAPACA2, only supermeres from PFUM1 and FUM2 consistently increased proliferation (9.5-35% increase, p=0.0051 to <0.0001). Ki-67 expression in MIAPACA2, increased by 9.6-23.0% following treatment by NPs (all p<0.0001) and by 2.9-9.2% with sEVs (p=0.011 to <0.0001). EMT was estimated by vimentin in MIAPACA2, as all preCAF fractions from PFUM1 reduced vimentin expression (p<0.001), while CAF FUM2 NPs increased vimentin expression (p<0.0001) while sEVs had no effect (p=0.075). In conclusion, the majority of pancreatic tumor-associated fibroblast small secretome is composed of NPs, exhibiting significant functional pro-tumoral effects. Citation Format: Ayman Al Shoukari, Maelle Batardiere, Nooshin Movahed, Camille beaussier, Jumanah Baig, Melissa gonzalez, Patricia Moraille, Eric Bonneil, Louise Rousseau, Simon turcotte, Kathleen Delgiorno, Marcus Tan, Anna Means, Elham Dianati Ajibisheh, Quoc-huy Trinh. Identification of new signaling pathways between fibroblasts & tumor cells in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1588.

Abstract 446: Integrated spatial transcriptomics and lipidomics analyses of intraductal papillary mucinous neoplasm identifies enrichment of long chain sulfatide as an early metabolic alteration

Abstract Purpose: To define the metabolic alterations associated with malignant progression of intraductal papillary mucinous neoplasm (IPMN). Experimental Procedures: Matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS) was conducted for spatial characterization of lipid profiles on frozen tissue sections from resected human IPMN patients. The specimen set consisted of either low-grade dysplasia (LG) (n=15), high-grade (HG) dysplasia (n=4), or with an associated pancreatic ductal adenocarcinoma (PDAC) (n=4) as well as 15 PDAC tissues. Utilizing serial sections to the same human IPMN cases analyzed with MALDI-MS imaging, we used the Visium Spatial Gene Expression technology platform to characterize the spatiomolecular underpinnings of LG and HG IPMN. H&E images of the same tissue section used for the Visium workflow, were used to annotate the spots in the dataset covering the epithelial lining of the IPMN lesions (“epilesional” areas) and the spots covering the adjacent microenvironment surrounding the lesion (“perilesiopecific” area). Findings were compared with lipidomic analyses of cystic fluid from 89 IPMN patients. The anti-cancer efficacy of UGT8-IN-1, a selective small molecule inhibitor of ceramide galactosyltransferase (CGT, also known as UGT8), was assessed in vitro and in mutant Kras;Gnas allografts. Results: MALDI/MS-based spatial imaging of human resected IPMN tissues and pancreata from a mutant Kras;Gnas mouse model of IPMN revealed long-chain hydroxylated sulfatides, particularly the C24:0(OH) and C24:1(OH) species, to be selectively enriched in the IPMN and PDAC neoplastic epithelium. Visium spatial transcriptomics data confirmed that the cognate transcripts engaged in sulfatide biosynthesis, including UGT8, Gal3St1, and FA2H, were co-localized with areas of sulfatide enrichment. Lipidomic analyses of cystic fluid from 89 patients with IPMN identified several sulfatide species to be significantly elevated in patients with IPMN/PDAC compared to those with low-grade IPMN. Inhibition of sulfatide metabolism via UGT8-IN-1 reduced viability of Kras;Gnas murine cell lines in vitro and attenuated tumor growth in an allograft IPMN model. UGT8-IN-1 treatment resulted in reduced levels of several sulfatide species, accompanied by a concomitant increase in a subset of quantified sulfatides precursor ceramides, accumulation of mitochondrial mass and reactive oxygen species and time-dependent increases in autophagy/mitophagy markers p62/SQSTM1 and LC-3B, suggesting impaired mitophagy. Conclusion: Enhanced sulfatide metabolism is an early alteration in cystic pre-cancerous lesions of the pancreas that persists through invasive neoplasia. Targeting sulfatide biosynthesis might represent an actionable vulnerability for cancer interception. Citation Format: Yihui Chen, Marta Sans, Fredrik Thege, Rongzhang Dou, Jimin Min, Michele Yip-Schneider, Jianjun Zhang, Ranran Wu, Ehsan Irajizad, Yuki Makino, Kimal Rajapakshe, Mark Hurd, Ricardo León-Letelier, Jody Vykoukal, Jennifer Dennison, Kim-Anh Do, Robert Wolff, Paola Guerrero, Michael Kim, Max Schmidt, Anirban Maitra, Samir Hanash, Johannes Fahrmann. Integrated spatial transcriptomics and lipidomics analyses of intraductal papillary mucinous neoplasm identifies enrichment of long chain sulfatide as an early metabolic alteration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 446.

Familial Intraductal Papillary Mucinous Neoplasm Associated With the Germline MSH6 Missense Variant and Progression of Pancreatic cancer.

Intraductal papillary mucinous neoplasm (IPMN) in individuals with at least one first-degree relative with IPMN is defined as familial IPMN. However, few studies have reported on familial IPMN, its clinical characteristics, or the associated genetic factors. We report the case of a 58-year-old woman with multifocal IPMN and a mural nodule in the pancreatic body. The patient underwent a distal pancreatectomy and developed pancreatic head cancer 1 year and 6 months postoperatively. The patient had a family history of multifocal IPMN in her father. Therefore, a genetic predisposition to IPMN and pancreatic cancer was suspected. The patient was analyzed for germline variants, and the resected IPMN was subjected to immunohistochemical and somatic variant analyses. Next-generation sequencing revealed a heterozygous germline missense variant in exon 5 of MSH6 (c.3197A>G; Tyr1066Cys). The pathogenicity of this variant of uncertain significance was suspected based on multiple in silico analyses, and the same MSH6 variant was identified in the patient's father's colonic adenoma. The mural nodule in the pancreatic body was pathologically diagnosed as a high-grade IPMN with ossification and somatic KRAS and PIK3CA variants. This case revealed a possible genetic factor for familial IPMN development and presented interesting clinicopathological findings.

Single-cell RNA sequencing highlights epithelial and microenvironmental heterogeneity in malignant progression of pancreatic ductal adenocarcinoma

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are bona fide precursor lesions of pancreatic ductal adenocarcinoma (PDAC). Single-cell transcriptomics provides a unique perspective for dissecting the epithelial and microenvironmental heterogeneity that accompanies progression from benign IPMNs to invasive PDAC. Single-cell RNA sequencing was performed through droplet-based sequencing on 35 693 cells from three high-grade IPMNs and two IPMN-derived PDACs (all surgically resected). Analysis of single-cell transcriptomes revealed heterogeneous alterations within the epithelium and the tumor microenvironment during the progression of noninvasive dysplasia to invasive cancer. For epithelial cells, we identified acinar–ductal cells and isthmus–pit cells enriched in IPMN lesions and profiled three types of PDAC-unique ductal cells. Notably, a proinflammatory immune component was distinctly observed in IPMNs, comprising CD4+ T cells, CD8+ T cells, and B cells, whereas M2 macrophages were significantly accumulated in PDAC. Through the analysis of cellular communication, the osteopontin gene (SPP1)–CD44 pathway between macrophages and epithelial cells were particularly strengthened in the PDAC group. Further prognostic analysis revealed that SPP1 is a biomarker of IPMN carcinogenesis for surveillance. This study demonstrates the ability to perform high-resolution profiling of single cellular transcriptomes during the progression of high-grade IPMNs to cancer. Notably, single-cell analysis provides an unparalleled insight into both epithelial and microenvironmental heterogeneity associated with early cancer pathogenesis and provides practical markers for surveillance and targets for cancer interception.

Immunohistochemical FAP Expression Reflects 68Ga-FAPI PET Imaging Properties of Low- and High-Grade Intraductal Papillary Mucinous Neoplasms and Pancreatic Ductal Adenocarcinoma.

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are grossly visible (typically > 5 mm) intraductal epithelial neoplasms of mucin-producing cells, arising in the main pancreatic duct or its branches. According to the current 2-tiered grading scheme, these lesions are categorized as having either low-grade (LG) dysplasia, which has a benign prognosis, or high-grade (HG) dysplasia, which formally represents a carcinoma in situ and thus can transform to pancreatic ductal adenocarcinoma (PDAC). Because both entities require different treatments according to their risk of becoming malignant, a precise pretherapeutic diagnostic differentiation is inevitable for adequate patient management. Recently, our group has demonstrated that 68Ga-fibroblast activation protein (FAP) inhibitor (FAPI) PET/CT shows great potential for the differentiation of LG IPMNs, HG IPMNs, and PDAC according to marked differences in signal intensity and tracer dynamics. The purpose of this study was to biologically validate FAP as a target for PET imaging by analyzing immunohistochemical FAP expression in LG IPMNs, HG IPMNs, and PDAC and comparing with SUV and time to peak (TTP) measured in our prior study. Methods: To evaluate the correlation of the expression level of FAP and α-smooth muscle actin (αSMA) in neoplasm-associated stroma depending on the degree of dysplasia in IPMNs, 98 patients with a diagnosis of LG IPMN, HG IPMN, PDAC with associated HG IPMN, or PDAC who underwent pancreatic surgery at the University Hospital Heidelberg between 2017 and 2023 were identified using the database of the Institute of Pathology, University Hospital Heidelberg. In a reevaluation of hematoxylin- and eosin-stained tissue sections of formalin-fixed and paraffin-embedded resection material from the archive, which was originally generated for histopathologic routine diagnostics, a regrading of IPMNs was performed by a pathologist according to the current 2-tiered grading scheme, consequently eliminating the former diagnosis of "IPMN with intermediate-grade dysplasia." For each case, semithin tissue sections of 3 paraffin blocks containing neoplasm were immunohistologically stained with antibodies directed against FAP and αSMA. In a masked approach, a semiquantitative analysis of the immunohistochemically stained slides was finally performed by a pathologist by adapting the immunoreactive score (IRS) and human epidermal growth factor receptor 2 (Her2)/neu score to determine the intensity and percentage of FAP- and αSMA-positive cells. Afterward, the IRS of 14 patients who underwent 68Ga-FAPI-74 PET/CT in our previous study was compared with their SUVmax, SUVmean, and TTP for result validation. Results: From 98 patients, 294 specimens (3 replicates per patient) were immunohistochemically stained for FAP and αSMA. Twenty-three patients had LG IPMNs, 11 had HG IPMNs, 10 had HG IPMNs plus PDAC, and 54 had PDAC. The tumor stroma was in all cases variably positive for FAP. The staining intensity, percentage of FAP-positive stroma, IRS, and Her2/neu score increased with higher malignancy. αSMA expression could be shown in normal pancreatic stroma as well as within peri- and intraneoplastic desmoplastic reaction. No homogeneous increase in intensity, percentage, IRS, and Her2/neu score with higher malignancy was observed for αSMA. The comparison of the mean IRS of FAP with the mean SUVmax, SUVmean, and TTP of 68Ga-GAPI-74 PET/CT showed a matching value increasing with higher malignancy in 68Ga-FAPI-74 PET imaging and immunohistochemical FAP expression. Conclusion: The immunohistochemical staining of IPMNs and PDAC validates FAP as a biology-based stromal target for invivo imaging. Increasing expression of FAP in lesions with a higher degree of malignancy matches the expectation of a stronger FAP expression in PDAC and HG IPMNs than in LG IPMNs and corroborates our previous findings of higher SUVs and a longer TTP in PDAC and HG IPMNs than in LG IPMNs.

Talniflumate abrogates mucin immune suppressive barrier improving efficacy of gemcitabine and nab-paclitaxel treatment in pancreatic cancer

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a lethal disease. This is due to its aggressive course, late diagnosis and its intrinsic drugs resistance. The complexity of the tumor, in terms of cell components and heterogeneity, has led to the approval of few therapies with limited efficacy. The study of the early stages of carcinogenesis provides the opportunity for the identification of actionable pathways that underpin therapeutic resistance.MethodsWe analyzed 43 Intraductal papillary mucinous neoplasms (IPMN) (12 Low-grade and 31 High-grade) by Spatial Transcriptomics. Mouse and human pancreatic cancer organoids and T cells interaction platforms were established to test the role of mucins expression on T cells activity. Syngeneic mouse model of PDAC was used to explore the impact of mucins downregulation on standard therapy efficacy.ResultsSpatial transcriptomics showed that mucin O-glycosylation pathway is increased in the progression from low-grade to high-grade IPMN. We identified GCNT3, a master regulator of mucins expression, as an actionable target of this pathway by talniflumate. We showed that talniflumate impaired mucins expression increasing T cell activation and recognition using both mouse and human organoid interaction platforms. In vivo experiments showed that talniflumate was able to increase the efficacy of the chemotherapy by boosting immune infiltration.ConclusionsFinally, we demonstrated that combination of talniflumate, an anti-inflammatory drug, with chemotherapy effectively improves anti-tumor effect in PDAC.

Abstract 945: Early detection of high-grade IPMN using extracellular vesicles - a successful patient story

Abstract Background/Purpose The detection of pancreatic ductal adenocarcinoma (PDAC) lesions at pre-cancerous or early-stages is critical to improving patient survival. The rise of liquid biopsies could potentially fill this unmet clinical need, such as our recently developed pancreatic LDT which isolates extracellular vesicles (EVs) from blood for detection of PDAC at earlier stages. In this case study, we describe a 60-year-old healthy male with acute pancreatitis who underwent an extensive imaging work-up that failed to detect radiographic evidence of lesions prior to surgery. Results from our EV-based early detection blood test, previously reported to have a specificity of 91.1% and sensitivity of 95.7% for stage I/II PDAC, indicated a high likelihood of PDAC. Subsequent pathology review after Whipple surgery confirmed high-grade intraductal papillary mucinous neoplasm (IPMN) and pancreatic intraepithelial neoplasms (PanINs). Case Description The patient was brought to the clinic for persistent abdominal bloating and pressure. A CT scan of the abdomen and an elevated lipase yielded a diagnosis of first episode of acute pancreatitis. Two MRIs of the abdomen confirmed an abnormal pancreatic duct dilatation, but no evident masses. An endoscopic ultrasound later demonstrated an abrupt stricture of the pancreatic duct. Due to complete duct occlusion, an endoscopic retrograde cholangiopancreatography (ERCP) was performed with stent placement. Cytology brushings from the ERCP were non-diagnostic, and CA-19-9 and CEA were non-elevated. The patient sought additional genetic analysis on his captured cyst fluid cells, which showed mutations in K-RAS and p53, raising clinical concern. Testing with a DNA-methylation test for cancer detection reported a result of “No Cancer Signal Detected”; however, blood testing with our EV-based early detection blood test indicated a high probability of PDAC. The patient decided to undergo a Whipple procedure. The final surgical pathology revealed a main-duct high-grade dysplasia IPMN with PanINs. Recovery post-surgery was unremarkable. Discussion This case report illustrates the successful clinical utility of an EV-based blood assay for detection of high-grade IPMN and PanINs, lesions not identified through extensive imaging workup lesion and destined, with high probability (~60-70%), to progress to a pancreatic cancer. The eventual impetus for this patient to undergo surgery was the combination of his known pancreatic duct pathology and other clinicopathological characteristics, with the results of the EV-based liquid biopsy test acting as an adjunct clinical tool to support to his decision. Conclusions PDAC is a lethal malignancy with a long-term survival of <10%. Detection at the earliest stage can be associated with >80% survival. A prospective, multi-center, observational registry study - ExoLuminate - is underway to further evaluate patients at high-risk for PDAC. Citation Format: Harmeet Dhani, Juan Hinestrosa, Heath I. Balcer, Edward Nolan, Razelle Kurzrock, Paul Billings. Early detection of high-grade IPMN using extracellular vesicles - a successful patient story [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 945.

IPMN-LEARN: A linear support vector machine learning model for predicting low-grade intraductal papillary mucinous neoplasms.

We aimed to build a machine learning tool to help predict low-grade intraductal papillary mucinous neoplasms (IPMNs) in order to avoid unnecessary surgical resection. IPMNs are precursors to pancreatic cancer. Surgical resection remains the only recognized treatment for IPMNs yet carries some risks of morbidity and potential mortality. Existing clinical guidelines are imperfect in distinguishing low-risk cysts from high-risk cysts that warrant resection. We built a linear support vector machine (SVM) learning model using a prospectively maintained surgical database of patients with resected IPMNs. Input variables included 18 demographic, clinical, and imaging characteristics. The outcome variable was the presence of low-grade or high-grade IPMN based on post-operative pathology results. Data were divided into a training/validation set and a testing set at a ratio of 4:1. Receiver operating characteristics analysis was used to assess classification performance. A total of 575 patients with resected IPMNs were identified. Of them, 53.4% had low-grade disease on final pathology. After classifier training and testing, a linear SVM-based model (IPMN-LEARN) was applied on the validation set. It achieved an accuracy of 77.4%, with a positive predictive value of 83%, a specificity of 72%, and a sensitivity of 83% in predicting low-grade disease in patients with IPMN. The model predicted low-grade lesions with an area under the curve of 0.82. A linear SVM learning model can identify low-grade IPMNs with good sensitivity and specificity. It may be used as a complement to existing guidelines to identify patients who could avoid unnecessary surgical resection.

Single-cell sequencing reveals heterogeneity between pancreatic adenosquamous carcinoma and pancreatic ductal adenocarcinoma with prognostic value.

Pancreatic adenosquamous carcinoma (ASPC) is a rare subtype of pancreatic cancer with lethal malignancy, and few studies have focused on the heterogeneity of ASPC. Here, we performed a single-cell sequencing procedure on pancreatic tumor tissue from an ASPC patient and a patient with high-grade intraductal papillary mucinous neoplasm (IPMN). Through the combined analysis of single-cell sequencing data from five pancreatic ductal adenocarcinoma (PDAC) patients, one IPMN patient, and one ASPC patient in a public database, we identified 11 main types of cells, including macrophages, B cells, cancer stem cells, ductal cells, fibroblasts, endo/stellate cells, neutrophils, acinar cells, T cells, natural killer (NK) cells, dendritic cells, and mast cells. Then, the different characteristics and differentiation paths of the immune microenvironment among IPMN, ASPC, and PDAC in macrophages, T cells, and cancer-associated fibroblasts (CAFs) were identified through multiple bioinformatics analyses. Two novel special cancer-associated fibroblasts were identified as nCAFs and imCAFs. Then, cancer cells in duct cells were identified using the infercnv software. Two ASPC-specific subgroups of cancer cells with squamous cell features were identified. Finally, the identified specific CAFs and cancer cells were mapped to TCGA-PAAD cohort through the cibersoftx software. All of these identified subgroups were calculated to have a significant prognostic value in pancreatic cancer patients. These findings will promote the clinical application of single-cell sequencing data of pancreatic cancer and deepen our understanding of ASPC.

Static and Dynamic 68Ga-FAPI PET/CT for the Detection of Malignant Transformation of Intraductal Papillary Mucinous Neoplasia of the Pancreas.

Pancreatic ductal adenocarcinoma (PDAC) may arise from intraductal papillary mucinous neoplasms (IPMN) with malignant transformation, but a significant portion of IPMN remains to show benign behavior. Therefore, it is important to differentiate between benign IPMN and IPMN lesions undergoing malignant transformation. However, nonoperative differentiation by ultrasound, CT, MRI, and carbohydrate antigen 19-9 (CA19-9) is still unsatisfactory. Here, we assessed the clinical feasibility of additional assessment of malignancy by PET using 68Ga-labeled fibroblast activation protein inhibitors (68Ga-FAPI PET) in 25 patients with MRI- or CT-proven cystic pancreatic lesions. Methods: Twenty-five patients with cystic pancreatic lesions who were followed up in the European Pancreas Center of Heidelberg University hospital and who were led to surgical resection or fine-needle aspiration due to suspicious clinical, laboratory chemistry, or radiologic findings were examined by static (all patients) and dynamic (20 patients) 68Ga-FAPI PET. Cystic pancreatic lesions were delineated and SUVmax and SUVmean were determined. Time-activity curves and dynamic parameters (time to peak, K 1, k 2, K3, k 4) were extracted from dynamic PET data. Receiver-operating curves of static and dynamic PET parameters were calculated. Results: Eleven of the patients had menacing IPMN (high-grade IPMN with [6 cases] or without [5 cases] progression into PDAC) and 11 low-grade IPMN; 3 patients had other benign entities. Menacing IMPN showed significantly elevated 68Ga-FAPI uptake compared with low-grade IPMN and other benign cystic lesions. In dynamic imaging, menacing IPMN showed increasing time-activity curves followed by slow decrease afterward; time-activity curves of low-grade IPMN showed an immediate peak followed by rapid decrease for about 10 min and slower decrease for the rest of the time. Receiver-operating curves showed high sensitivity and specificity (area under the curve greater than 80%) of static and dynamic PET parameters for the differentiation of IPMN subtypes. Conclusion: 68Ga-FAPI PET is a helpful new tool for the differentiation of menacing and low-grade IPMN and shows the potential to avoid unnecessary surgery for nonmalignant pancreatic IPMN.

Use of Autoreactive Antibodies in Blood of Patients with Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMN) for Grade Distinction and Detection of Malignancy.

Simple SummaryRisk stratification via biomarkers used with imaging could support predicting high-risk pancreatic intraductal papillary mucinous neoplasms (IPMN) with malignant potential. We explored the presence of autoreactive antibodies in the blood of patients with IPMN of different grades of dysplasia, including IPMN with associated invasive carcinoma and early-stage pancreatic ductal adenocarcinoma (PDAC), to identify signatures of early malignancy. Multivariate predictive models retained 14 proteins as potential biomarkers for discrimination between all disease classes. The integration of the autoreactive-antibody panel with clinical variables may aid in risk stratification of high-risk IPMN patients, which would subsequently improve clinical management.(1) Background: A reliable non-invasive distinction between low- and high-risk pancreatic intraductal papillary mucinous neoplasms (IPMN) is needed to effectively detect IPMN with malignant potential. This would improve preventative care and reduce the risk of developing pancreatic cancer and overtreatment. The present study aimed at exploring the presence of autoreactive antibodies in the blood of patients with IPMN of various grades of dysplasia. (2) Methods: A single-center cohort was studied composed of 378 serum samples from patients with low-grade IPMN (n = 91), high-grade IPMN (n = 66), IPMN with associated invasive cancer (n = 30), pancreatic ductal adenocarcinoma (PDAC) stages T1 (n = 24) and T2 (n = 113), and healthy controls (n = 54). A 249 full-length recombinant human protein microarray was used for profiling the serum samples. (3) Results: 14 proteins were identified as potential biomarkers for grade distinction in IPMN, yielding high specificity but mediocre sensitivity. (4) Conclusions: The identified autoantibodies are potential biomarkers that may assist in the detection of malignancy in IPMN patients.

Diminished Immune Surveillance during Histologic Progression of Intraductal Papillary Mucinous Neoplasms Offers a Therapeutic Opportunity for Cancer Interception.

Intraductal papillary mucinous neoplasms (IPMN) are bona fide precursors to pancreatic ductal adenocarcinoma (PDAC). While genomic alterations during multistep IPMN progression have been well cataloged, the accompanying changes within the tumor immune microenvironment (TIME) have not been comprehensively studied. Herein, we investigated TIME-related alterations during IPMN progression, using multiplex immunofluorescence (mIF) coupled with high-resolution image analyses. Two sets of formalin-fixed, paraffin-embedded tissue samples from surgically resected IPMNs were analyzed. The training set of 30 samples consisted of 11 low-grade IPMN (LG-IPMN), 17 high-grade IPMN (HG-IPMN), and 2 IPMN with PDAC, while a validation set of 93 samples comprised of 55 LG-IPMN and 38 HG-IPMN. The training set was analyzed with two panels of immuno-oncology-related biomarkers, while the validation set was analyzed with a subset of markers found significantly altered in the training set. Cell types indicative of enhanced immune surveillance, including cytotoxic and memory T cells, and antigen-experienced T cells and B cells, were all found at higher densities within isolated LG-IPMNs compared with HG-IPMNs. Notably, the TIME of LG-IPMNs that had progressed at the time of surgical resection (progressor LGD) resembled that of the synchronous HG-IPMNs, underscoring that attenuated immune surveillance occurs even in LG-IPMNs destined for progression. Our findings provide a basis for interception of cystic neoplasia to PDAC, through maintenance of sustained immune surveillance using vaccines and other prevention approaches.

Pancreatic medullary carcinoma developed on a pancreatic intraductal papillary mucinous neoplasm with loss of MSH2 and MSH6 expression: a case report

BackgroundPancreatic medullary carcinoma (PMC) is a rare pancreatic tumor, usually showing the presence of microsatellite instability, mostly MLH1 silencing, and a wild-type KRAS mutation status. We report here a PMC arising from a Pancreatic Intraductal Papillary Mucinous Neoplasm (IPMN), both having KRAS and TP53 mutations.Case presentationWe report the case of a 73-year-old woman presenting with right iliac fossa pain. MRI revealed a 16 mm diameter mass in the pancreas, leading to a pancreatic duct stricture and upstream a dilatation of the distal pancreatic duct of Wirsung. A fine needle aspiration was performed, and pathology analysis revealed malignant glandular cells. The patient underwent distal pancreatectomy.Gross examination revealed an12 mm indurated white lesion, adjacent to a cystic lesion extending into the rest of the pancreatic body.Microscopically, the cystic area represented a mixed (gastric-type and pancreatobiliary-type) IPMN, involving the main and secondary pancreatic ducts with low-grade and high-grade dysplasia. In the periphery of this IPMN, a 14mm associated invasive carcinoma was observed, characterized by focal gland formation and by poorly differentiated cells with a syncytial appearance, associated with a dense lymphoplasmocytic and neutrophilic infiltrate.Immunohistochemical analyses showed loss of MSH2 and MSH6 expression. Microsatellite instability was confirmed by molecular test.Molecular analysis was performed both on the invasive carcinoma and on the high-grade dysplasia IPMN, revealing the same mutation profile with KRAS and TP53 mutations.The proposed diagnosis was mixed IPMN with associated invasive medullary carcinoma that presented loss of MSH2 and MSH6 expression.ConclusionsThe present case reports for the first time, at the best of our knowledge, the coexistence of IPMN lesions and PMC, both having the same molecular alterations. It also describes the second case of PMC with microsatellite instability, MSH2 and MSH6 silenced.

Noninvasive risk stratification of intraductal papillary mucinous neoplasia with malignant potential by serum apolipoprotein-A2-isoforms.

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant lesions of pancreatic cancer. An accurate serum biomarker, which allows earlier identification of asymptomatic individuals with high-risk for developing cancer, is of urgent need. Apolipoprotein A2-isoforms (apoA2-i) have previously been identified as biomarkers in pancreatic cancer. This study investigates a potential clinical application of the serum apoA2-i for risk stratification of IPMN and associated cancer. The concentrations of apoA2-i were retrospectively determined in 523 patient sera specimen, composed of 305 IPMNs with preinvasive lesions with different grades of dysplasia and invasive cancer, 140 pancreatic ductal adenocarcinoma, 78 with other cystic lesions and healthy controls cohorts, using an apoA2-i enzyme-linked immunosorbent assay kit. The diagnostic performance of serum apoA2-i was assessed and compared to routine clinical marker CA 19-9. ApoA2-i levels were significantly reduced in all IPMN samples regardless of stage compared to healthy controls. Receiver operating characteristic curve analysis of IPMNs with high-grade dysplasia and IPMN with associated carcinoma revealed the area under curve (AUC) of 0.91 and >0.94, respectively. The respective sensitivities were 70% and 83% with a specificity of 95%, and significantly higher than the gold standard biomarker CA 19-9. AUC values of apoA2-i for detecting IPMN-associated carcinoma of colloid and ductal subtypes were 0.990 and 0.885, respectively. ApoA2-i has the potential to early detect the risk of malignancy of patients with IPMN. The serological apoA2-i test in combination with imaging modalities could help improve the diagnosis of IPMN malignancy. Further validation in larger and independent international cohort studies is needed.

Invasive Large Duct Type Pancreatic Adenocarcinoma: A Diagnostically Challenging Entity

Abstract Introduction/Objective Large duct type invasive pancreatic adenocarcinoma is a morphological variant of pancreatic ductal adenocarcinoma that poses a radiologic and pathologic diagnostic challenge as it closely mimics other non- invasive neoplasms, including mucinous cystic neoplasms and intraductal papillary mucinous neoplasms (IPMN). We report a case of large duct type invasive adenocarcinoma that on radiology closely mimics an IPMN. Methods/Case Report The case id that of a 73-year-old male presenting with weight loss and chronic diarrhea. Abdominal imaging revealed features suggestive of main duct IPMN with possible side branch extension into the pancreatic head. Endoscopic retrograde cholangiopancreatography showed a bile duct stricture that was stented and biopsied, revealing mucinous material with neoplastic cells. A Whipple procedure was performed, revealing a 3.3 cm, tank-pink, papillary lesion in the pancreatic head, that is partially cystic with mucinous contents, and displaying exophytic extension into the main pancreatic duct. Microscopically, the lesion consists of a high-grade IPMN involving the main pancreatic duct with side branch extension, and associated with invasive adenocarcinoma, the majority of which is of the large duct type, showing irregularly distributed large ducts with jagged edges and surrounding desmoplasia, with intra-luminal mucinous material and neutrophils. The lining cells show focal pseudo-stratification and bland cytology. Foci of conventional type invasive adenocarcinoma, clusters of invasive tumor cells, and peri-neural invasion are also identified. Post- procedure, the patient underwent chemotherapy with marked symptomatic improvement. Results (if a Case Study enter NA) NA Conclusion Large duct type invasive adenocarcinoma of the pancreas can closely mimic non-invasive pancreatic neoplasms, posing diagnostic challenges that require identification of subtle features to achieve the correct diagnosis and guide treatment.

Neutrophil-to-lymphocyte Ratio as a Predictor of Malignancy of Intraductal Papillary Mucinous Neoplasms.

Intraductal papillary mucinous neoplasm (IPMN) can lead, via the adenoma-carcinoma sequence, to invasive adenocarcinoma, which has a poor prognosis. Most IPMNs do not meet the indications for surgery and instead are monitored regularly, but no biomarkers of malignant transformation during surveillance have been established. A total of 50 patients with IPMN who underwent pancreatectomy were evaluated retrospectively. Clinicopathological parameters during the surveillance period before surgery were assessed to explore biomarkers for predicting malignancy. The serum level of carbohydrate antigen 19-9 was significantly higher in IPMN-derived invasive adenocarcinoma. The neutrophil-to-lymphocyte ratio was significantly lower in low-grade IPMN than high-grade and Inv-IPMN cases by univariate and multivariate analysis. Disease-free survival was significantly shorter in patients with high-grade and invasive IPMN compared with those with low-grade IPMN. In patients whose preoperative surveillance was performed for more than 12 months, the neutrophil-to-lymphocyte ratio was significantly higher in those with high-grade and invasive IPMNs compared with patients with low-grade IPMN in the year before surgery. The NLR is a useful biomarker for distinguishing between low-grade and high-grade IPMN and thus should be monitored during surveillance.

Pre-Operative Imaging and Pathological Diagnosis of Localized High-Grade Pancreatic Intra-Epithelial Neoplasia without Invasive Carcinoma

Simple SummaryPancreatic ductal adenocarcinoma (PDAC) is typically associated with an extremely poor prognosis; however, small PDAC tumors show good prognosis. High-grade pancreatic intra-epithelial neoplasia (PanIN), which precedes invasive PDAC, is a primary target for improving the prognosis of PDAC. However, detection of high-grade PanIN without invasive carcinoma by existing imaging modalities is difficult because the lesions are only microscopically detectable. Recent studies have reported the characteristics of imaging findings associated with localized high-grade PanIN and the usefulness of serial pancreatic-juice aspiration cytologic examination as a method to confirm the pre-operative histopathology. In this review, we aimed to clarify recent clinical findings regarding detection of localized high-grade PanIN, which may contribute to improvement of the prognosis of patients with PDAC.Pancreatic ductal adenocarcinoma (PDAC) arises from precursor lesions, such as pancreatic intra-epithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). The prognosis of high-grade precancerous lesions, including high-grade PanIN and high-grade IPMN, without invasive carcinoma is good, despite the overall poor prognosis of PDAC. High-grade PanIN, as a lesion preceding invasive PDAC, is therefore a primary target for intervention. However, detection of localized high-grade PanIN is difficult when using standard radiological approaches. Therefore, most studies of high-grade PanIN have been conducted using specimens that harbor invasive PDAC. Recently, imaging characteristics of high-grade PanIN have been revealed. Obstruction of the pancreatic duct due to high-grade PanIN may induce a loss of acinar cells replaced by fibrosis and lobular parenchymal atrophy. These changes and additional inflammation around the branch pancreatic ducts (BPDs) result in main pancreatic duct (MPD) stenosis, dilation, retention cysts (BPD dilation), focal pancreatic parenchymal atrophy, and/or hypoechoic changes around the MPD. These indirect imaging findings have become important clues for localized, high-grade PanIN detection. To obtain pre-operative histopathological confirmation of suspected cases, serial pancreatic-juice aspiration cytologic examination is effective. In this review, we outline current knowledge on imaging characteristics of high-grade PanIN.

Recurrence Patterns after Surgical Resection of Intraductal Papillary Mucinous Neoplasm (IPMN) of Pancreas; a Multicenter, Retrospective Study of 1,074 IPMN Patients by Japan Pancreas Society

Introduction: Although there are numerous reports focusing on surgical indication for intraductal papillary mucinous neoplasm (IPMN), the recurrence patterns following surgery are less widely reported. To ascertain optimal treatment and postoperative surveillance for IPMN patients, we analyzed patterns and risk factors for recurrence after surgery for IPMN. Methods: This study is a retrospective, multi-institutional, observational study, including 1,074 patients undergoing surgery for IPMN at 11 academic institutions. We analyzed risk factors for recurrence after classifying postoperative recurrences into metachronous high-risk lesions (malignant progression of IPMN and/or metachronous pancreatic ductal adenocarcinoma) in the remnant pancreas and extra-pancreatic recurrence. Results: Of 1,074 patients undergoing surgery for IPMN, 155 patients (14.4%) developed postoperative recurrence. We found that 34.3% of 70 high-risk lesions in the remnant pancreas occurred over 5 years after surgery, and survival of 36 patients undergoing second operation for high-risk lesions was better than that of 34 patients who did not (P=0.04). We found four independent risk factors for metachronous high-risk lesions in remnant pancreas: symptoms (P=0.005, hazard ratio [HR]: 1.988), location of pancreatic body/tail (P< 0.001, HR: 3.876), main duct size ≥10 mm (P=0.021, HR: 1.900), and high-grade dysplasia/invasive intraductal papillary mucinous carcinoma (IPMC) (P< 0.001, HR: 3.204). Although six patients (0.7%) with low- or high-grade dysplasia IPMN developed extra-pancreatic recurrence, invasive IPMC was the strongest risk factor for extra-pancreatic recurrence (P< 0.001, HR: 39.667). Conclusion: We suggest that life-time continuous surveillance might be necessary for IPMN patients. Second surgery for metachronous high-risk lesions in remnant pancreas should be considered.

The Impact of Clinical and Pathological Features on Intraductal Papillary Mucinous Neoplasm Recurrence After Surgical Resection: Long-Term Follow-Up Analysis.

This study aimed to identify risk factors for recurrence after pancreatic resection for intraductal papillary mucinous neoplasm (IPMN). Long-term follow-up data on recurrence after surgical resection for IPMN are currently lacking. Previous studies have presented mixed results on the role of margin status in risk of recurrence after surgical resection. A total of 126 patients that underwent resection for noninvasive IPMN were followed for a median of 9.5 years. Dedicated pathological and radiological reviews were performed to correlate clinical and pathological features (including detailed pathological features of the parenchymal margin) with recurrence after surgical resection. In addition, in a subset of 32 patients with positive margins, we determined the relationship between the margin and original IPMN using driver gene mutations identified by next-generation sequencing. Family history of pancreatic cancer and high-grade IPMN was identified as risk factors for recurrence in both uni- and multivariate analysis (adjusted hazard ratio 3.05 and 1.88, respectively). Although positive margin was not significantly associated with recurrence in our cohort, the size and grade of the dysplastic focus at the margin were significantly correlated with recurrence in margin-positive patients. Genetic analyses showed that the neoplastic epithelium at the margin was independent from the original IPMN in at least 9 of 32 cases (28%). The majority of recurrences (74%) occurred after 3 years, and a significant minority (32%) occurred after 5 years. Sustained postoperative surveillance for all patients is indicated, particularly those with risk factors such has family history and high-grade dysplasia.

Recurrence patterns after surgical resection of intraductal papillary mucinous neoplasm (IPMN) of the pancreas; a multicenter, retrospective study of 1074 IPMN patients by the Japan Pancreas Society.

Although there are numerous reports focusing on surgical indication for intraductal papillary mucinous neoplasm (IPMN), the recurrence patterns following surgery are less widely reported. To ascertain optimal treatment and postoperative surveillance for IPMN patients, we analyzed patterns and risk factors for recurrence after surgery for IPMN. This study is a retrospective, multi-institutional, observational study, including 1074 patients undergoing surgery for IPMN at 11 academic institutions. We analyzed the risk factors for recurrence after classifying postoperative recurrences into metachronous high-risk lesions (malignant progression of IPMN and/or metachronous pancreatic ductal adenocarcinoma) in the remnant pancreas and extra-pancreatic recurrence. Of 1074 patients undergoing surgery for IPMN, 155 patients (14.4%) developed postoperative recurrence. We found that 34.3% of 70 high-risk lesions in the remnant pancreas occurred over 5years after surgery, and survival of 36 patients undergoing second operation for high-risk lesions was better than that of 34 patients who did not (P = 0.04). We found four independent risk factors for metachronous high-risk lesions in remnant pancreas: symptoms [P = 0.005, hazard ratio (HR) 1.988], location of pancreatic body/tail (P < 0.001, HR 3.876), main duct size ≥ 10mm (P = 0.021, HR 1.900), and high-grade dysplasia/invasive intraductal papillary mucinous carcinoma (IPMC) (P < 0.001, HR 3.204). Although six patients (0.7%) with low- or high-grade dysplasia IPMN developed extra-pancreatic recurrence, invasive IPMC was the strongest risk factor for extra-pancreatic recurrence (P < 0.001, HR 39.667). We suggest that life-time continuous surveillance might be necessary for IPMN patients. Second surgery for metachronous high-risk lesions in remnant pancreas should be considered to improve survival.