Progression Of Intraductal Papillary Mucinous Neoplasms Research Articles

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.

Deficient Rnf43 potentiates hyperactive Kras-mediated pancreatic preneoplasia initiation and malignant transformation.

BackgroundLargely due to incidental detection, asymptomatic pancreatic cystic lesions (PCLs) have become prevalent in recent years. Among them, intraductal papillary mucinous neoplasm (IPMN) infrequently advances to pancreatic ductal adenocarcinoma (PDAC). Conservative surveillance versus surgical intervention is a difficult clinical decision for both caregivers and PCL patients. Because RNF43 loss‐of‐function mutations and KRAS gain‐of‐function mutations concur in a subset of IPMN and PDAC, their biological significance and therapeutic potential should be elucidated.MethodsPancreatic Rnf43 knockout and Kras activated mice (Rnf43 −/−; KrasG12D ) were generated to evaluate their clinical significance in pancreatic pre‐neoplastic initiation and malignant transformation.ResultsLoss of Rnf43 potentiated the occurrence and severity of IPMN and PDAC in oncogenic Kras mice. The Wnt/β‐catenin signaling pathway was activated in pancreatic KrasG12D and Rnf43 knockout mice and the PORCN inhibitor LGK974 blocked pancreatic IPMN initiation and progression to PDAC accordingly.ConclusionsRnf43 is a tumor suppressor in the prevention of pancreatic malignant transformation. This genetically reconstituted autochthonous pancreatic Rnf43 −/−; KrasG12D preclinical cancer model recapitulates the pathological process from pancreatic cyst to cancer in humans and can be treated with inhibitors of Wnt/β‐catenin signaling. Since the presence of RNF43 and KRAS mutations in IPMNs predicts future development of advanced neoplasia from PCLs, patients with these genetic anomalies warrant surveillance, surgery, and/or targeted therapeutics such as Wnt/β‐catenin inhibitors.

Intraductal Papillary Mucinous Carcinoma Versus Conventional Pancreatic Ductal Adenocarcinoma: A Comprehensive Review of Clinical-Pathological Features, Outcomes, and Molecular Insights.

Intraductal papillary mucinous neoplasms (IPMN) are common and one of the main precursor lesions of pancreatic ductal adenocarcinoma (PDAC). PDAC derived from an IPMN is called intraductal papillary mucinous carcinoma (IPMC) and defines a subgroup of patients with ill-defined specificities. As compared to conventional PDAC, IPMCs have been associated to clinical particularities and favorable pathological features, as well as debated outcomes. However, IPMNs and IPMCs include distinct subtypes of precursor (gastric, pancreato-biliary, intestinal) and invasive (tubular, colloid) lesions, also associated to specific characteristics. Notably, consistent data have shown intestinal IPMNs and associated colloid carcinomas, defining the “intestinal pathway”, to be associated with less aggressive features. Genomic specificities have also been uncovered, such as mutations of the GNAS gene, and recent data provide more insights into the mechanisms involved in IPMCs carcinogenesis. This review synthetizes available data on clinical-pathological features and outcomes associated with IPMCs and their subtypes. We also describe known genomic hallmarks of these lesions and summarize the latest data about molecular processes involved in IPMNs initiation and progression to IPMCs. Finally, potential implications for clinical practice and future research strategies are discussed.

Prognostic impact of conservative surgery for pancreatic IPMNs

BackgroundThe extent of pancreatic resection for intraductal papillary mucinous neoplasms (IPMNs) remains an unresolved issue. The study aims at analyzing the prognostic impact of conservative surgery (CS) i.e. of pancreatoduodenectomy or distal pancreatectomy, versus total pancreatectomy (TP), for pancreatic IPMNs. MethodsWe retrospectively analyzed and compared data of patients who had undergone pancreatic resection for IPMNs at our center between November 2007 and April 2019. Patients were divided into two main groups based on the extent of surgery: TP-group and CS-group. Subsequently, the perioperative and the long-term outcomes were compared. Moreover, a sub-group analysis of patients with IPMN alone and patients with malignant IPMN, based on preoperative indications to surgery and post-operative histopathological findings, was also performed. ResultsFifty-three patients were included in the TP-group and 73 in the CS-group. In 50 (39.7%) cases the frozen section changed the pre-operative surgical planning, with an extension of the pancreatic resection, in 43 (34.1%) cases up to a total pancreatectomy. Twenty-six patients (20.6%) with low-grade dysplasia at the frozen section underwent CS, while twenty (15.8%) underwent TP. Comparing these two sub-groups no differences were found in surgical IPMN recurrence, nor progression. The rate of overall postoperative complications was 56.6% in the TP-group and 57.5% in the CS-group (p = 0.940). Fifteen patients (20.5%) developed diabetes in the CS-group.None of the patients treated with CS developed a surgical IPMN recurrence or progression during the follow-up period. Comparing OS and DFS of the two groups, we did not find any statistically significant difference (p = 0.619 and 0.315). ConclusionA timely CS can be considered an appropriate and valid strategy in the surgical treatment of the majority of pancreatic IPMNs, as it can avoid the serious long-term metabolic consequences of TP in patients with a long-life expectancy. On the contrary, TP remains mandatory in case of PDAC or high-risk features involving the entire gland.

Metabolic Characterization of Plasma and Cyst Fluid from Cystic Precursors to Pancreatic Cancer Patients Reveal Metabolic Signatures of Bacterial Infection.

Pancreatic cancer is the seventh leading cause of cancer-related death worldwide, with a 5 year survival rate as low as 9%. One factor complicating the management of pancreatic cancer is the lack of reliable tools for early diagnosis. While up to 50% of the adult population has been shown to develop precancerous pancreatic cysts, limited and insufficient approaches are currently available to determine whether a cyst is going to progress into pancreatic cancer. Recently, we used metabolomics approaches to identify candidate markers of disease progression in patients diagnosed with intraductal papillary mucinous neoplasms (IPMNs) undergoing pancreatic resection. Here, we enrolled an independent cohort to verify the candidate markers from our previous study with orthogonal quantitative methods in plasma and cyst fluid from serous cystic neoplasm and IPMN (either low- or high-grade dysplasia or pancreatic ductal adenocarcinoma). We thus validated these markers with absolute quantitative methods through the auxilium of stable isotope-labeled internal standards in a new independent cohort. Finally, we identified novel markers of IPMN status and disease progression-including amino acids, carboxylic acids, conjugated bile acids, free and carnitine-conjugated fatty acids, purine oxidation products, and trimethylamine-oxide. We show that the levels of these metabolites of potential bacterial origin correlated with the degree of bacterial enrichment in the cyst, as determined by 16S RNA. Overall, our findings are interesting per se, owing to the validation of previous markers and identification of novel small molecule signatures of IPMN and disease progression. In addition, our findings further fuel the provoking debate as to whether bacterial infections may represent an etiological contributor to the development and severity of the disease in pancreatic cancer, in like fashion to other cancers (e.g., Helicobacter pylori and gastric cancer).

Establishing a living biobank of patient-derived organoids of intraductal papillary mucinous neoplasms of the pancreas

AbstractPancreatic cancer (PaCa) is the third leading cause of cancer-related deaths in the United States. There is an unmet need to develop strategies to detect PaCa at an early, operable stage and prevent its progression. Intraductal papillary mucinous neoplasms (IPMNs) are cystic PaCa precursors that comprise nearly 50% of pancreatic cysts detected incidentally via cross-sectional imaging. Since IPMNs can progress from low- and moderate-grade dysplasia to high-grade dysplasia and invasion, the study of these lesions offers a prime opportunity to develop early detection and prevention strategies. Organoids are an ideal preclinical platform to study IPMNs, and the objective of the current investigation was to establish a living biobank of patient-derived organoids (PDO) from IPMNs. IPMN tumors and adjacent normal pancreatic tissues were successfully harvested from 15 patients with IPMNs undergoing pancreatic surgical resection at Moffitt Cancer Center & Research Institute (Tampa, FL) between May of 2017 and March of 2019. Organoid cultures were also generated from cryopreserved tissues. Organoid count and size were determined over time by both Image-Pro Premier 3D Version 9.1 digital platform and Matlab application of a Circular Hough Transform algorithm, and histologic and genomic characterization of a subset of the organoids was performed using immunohistochemistry and targeted sequencing, respectively. The success rates for organoid generation from IPMN tumor and adjacent normal pancreatic tissues were 81% and 87%, respectively. IPMN organoids derived from different epithelial subtypes showed different morphologies in vitro, and organoids recapitulated histologic and genomic characteristics of the parental IPMN tumor. In summary, this preclinical model has the potential to provide new opportunities to unveil mechanisms of IPMN progression to invasion and to shed insight into novel biomarkers for early detection and targets for chemoprevention.The authors report the feasibility of generating, expanding, and enumerating viable patient-derived intraductal papillary mucinous neoplasm (IPMN) tumor and normal pancreatic organoids from fresh and cryopreserved resected tissue. Organoids were characterized histologically and genomically and recapitulated the morphological and mutational profiles of resected IPMNs, suggesting promise of organoids for translational efforts.

Case study: low grade dysplasia of intraductal papillary mucinous neoplasm progression to metastatic pancreatic adenocarcinoma despite complete pathologic resection

Presenter: Dena Steiner MD | Saint Elizabeth's Medical Center Background: Intraductal Papillary Mucinous Neoplasm (IPMN) management has been closely monitored due to the potentially high morbidity of unnecessary resection and the high mortality of delayed diagnosis of pancreatic cancer. Methods: This case study demonstrates a newly developed pancreatic cancer from the bed of a minimally symptomatic 4x3 cm low grade IPMN found on imaging with pancreatic dilation, mucin, a 15 x 10 mm mural nodule and multiple septations. Endoscopic ultrasound cytology was inconclusive for malignant cells, and a subsequent whipple procedure was revealing for mixed duct IPMN with low grade dysplasia, negative margins and 14 negative nodes. Results: One year later, he presented with bloating and subsequent imaging revealed metastatic cancer at the pancreatic bed and liver. He underwent chemotherapy and received palliative care following this diagnosis. Conclusion: Typically, low grade dysplasia in IPMNs subjugates them to a benign categorization, however this case challenges that determination. Malignant potential remains in these lesions with low grade dysplasia; and the mere presence of an IPMN may be a marker that all the patient’s pancreatic cells are at risk for malignant degeneration. Additionally, subcategorization into gastric, intestinal, pancreaticobiliary and oncocytic subtypes and determination of MUC13 expression may provide improved risk stratification.

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.

Intestinal phenotype is maintained by Atoh1 in the cancer region of intraductal papillary mucinous neoplasm.

Intraductal papillary mucinous neoplasm (IPMN) is a precancerous lesion of pancreatic cancer. Although there are 4 types of IPMN, among which intestinal‐type IPMN is likely to progress into invasive cancer known as colloid carcinoma, no information regarding the involvement of the intestinal phenotype in the carcinogenesis of IPMN exists. The present study was conducted to explore how the intestinal differentiation system is maintained during the tumor progression of intestinal‐type IPMN using surgical resection specimens. Results showed that Atoh1, a critical transcriptional factor for intestinal differentiation toward the secretory lineages of intestinal epithelial cells, was expressed in an invasive‐grade IPMN. To determine the function of Atoh1 in pancreatic cancer, we generated a pancreatic ductal adenocarcinoma (PDAC) cell line overexpressing Atoh1. In a xenograft model, we successfully induced an IPMN phenotype in PDAC cells via Atoh1 induction. Finally, for the first time, we discovered that GPA33 is expressed in intestinal‐type IPMN, thereby suggesting a novel target for cancer therapy. In conclusion, the intestinal differentiation system might be maintained during tumor progression of intestinal‐type IPMN. Further analysis of the function of Atoh1 in IPMN might be useful for understanding the molecular mechanism underlying the malignant potential during the tumor progression of IPMN.

Abstract 1102: Model optimization and chemoprevention of IPMN driven PDAC in KPSD4 mouse model

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with one of the lowest five-year survival rates. Patients with intraductal papillary mucinous neoplasms (IPMN) or mucinous cystic neoplasms (MCNs) are at high risk for the development of PDAC and thus are target populations for intervention with chemopreventive agents. The lack of optimized animal models of IPMNs has limited the development of chemopreventive agents and vaccines. We have thus characterized the suitability of the Pdx1Cre.LSL-KrasG12D.SMAD4flox/flox (KPSD4) model for IPMN formation and their progression to PDAC. In addition, as a proof-of-principle we assessed the chemopreventive efficacy of gefitinib in the KPSD4 model. The development of IPMNs and PDAC were monitored up to 44 weeks of age by serial sacrifice at 6, 12, 18, 24, 36, and 44 weeks of age in male and female KPSD4 mice (n=6/time point), at which time the pancreata were analyzed for lesion development. The KPSD4 mouse model developed both IPMNs and pancreatic intraepithelial neoplasia (PanINs) spontaneously. IPMNs were histologically classified as i) independent (single IPMN duct); ii) IPMN cluster/adenoma (multiple IPMN ducts as cluster or adenoma); iii) IPMN borderline (dysplasia with or without CIS); and iv) IPMN invasive carcinoma. At 6 weeks of age, the pancreata were normal in appearance (&amp;gt;94% in male; &amp;gt;97% female) with low frequency (Mean ± SEM) of PanINs (Male, 6.5±2.65; Female, 3.44±2.12) and IPMNs (Male, 5.5±2.21; Female, 2.56±0.96). At 12 weeks of age, there was a significant increase of IPMN number and their progression to borderline type that advanced to carcinoma by age 24 weeks. At 36 weeks of age, &amp;gt;80% of the KPSD4 mice developed carcinomas that rapidly spread to the entire pancreas by 44 weeks of age. Overall, IPMN progression to PDAC required somewhat less time than did the progression of PanINs to PDAC in the KPSD4 mouse model. A major limitation of the KPSD4 model was the mortality due to secondary phenotypes. In KPSD4 mice, ~40% mortality was observed between 6 and 18 weeks of age due to intestinal tumors leading to obstruction. For the chemopreventive efficacy bioassay, 6 week old male and female KPSD4 mice (34/group) were fed diets containing 0 or 100 ppm of gefitinib for 18 weeks. Mice were euthanized at 24 weeks of age and pancreata were assessed for IPMNs, PanINs, and PDAC. Control-diet-fed male and female mice showed IPMN driven PDAC incidences of 83% and 100%, respectively, whereas male and female KPSD4 mice exposed to 100 ppm gefitinib showed PDAC incidences of 50% and 27% (p&amp;lt;0.0006), respectively. A significant reduction of IPMN individual ducts, adenoma, and IPMN borderline was observed in KPSD4 mice fed gefitinib, thus demonstrating a strong suppression of IPMN individual duct progression to more advanced lesions upon treatment with gefitinib. [Supported by NCI HHSN261201500038I]. Citation Format: Gaurav Kumar, Venkateshwar Madka, Anil Singh, Nandini Kumar, Nicole Stratton, Stanley Lightfoot, Altaf Mohammed, Mark S. Miller, Chinthalapally V. Rao. Model optimization and chemoprevention of IPMN driven PDAC in KPSD4 mouse model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1102.

Diabetes and Weight Loss Are Associated With Malignancies in Patients With Intraductal Papillary Mucinous Neoplasms

The role of diabetes in intraductal papillary mucinous neoplasms (IPMNs) is not known. We investigated the prevalence of diabetes among patients with resected IPMNs and the association between diabetes, clinical and morphological features, and high-grade dysplasia or invasive cancer. We collected clinical, pathology, laboratory, and demographic data from 134 patients who underwent pancreatic resection for IPMN from a referral center in Germany. We identified 50 patients with diabetes (37%). Higher proportions of patients with diabetes were male and older, but did not have increased body mass index, compared to patients without diabetes. Diabetes was significantly associated with main-duct involvement (odds ratio [OR], 2.827; 95% CI, 1.059-7.546; P = .038) and high-grade dysplasia or invasive carcinoma (OR, 2.692; 95% CI, 1.283-5.651; P = .009). Risk of high-grade dysplasia or invasive cancer was even higher in patients with new-onset or worsening diabetes (OR, 4.615; 95% CI, 1.423-14.698; P = .011). Fifty-eight percent of patients (18/31) with weight loss at diagnosis had diabetes vs 32% of patients (31/97) without weight loss (P=.009). However, when the analysis was restricted to IPMNs with low-grade dysplasia, weight loss and diabetes were no longer associated (42% [5/12] vs 21% [9/44]; P = .133). In patients with IPMNs, diabetes is associated with increased risk of main duct involvement and high-grade dysplasia or invasive carcinoma. Studies are needed to determine the relationship between diabetes and progression of IPMNs, which might lead to strategies for early detection and prevention of invasive cancer. Findings from this study should be considered in the guidelines for management of IPMN.

Abstract C46: Establishing a living biobank of patient-derived organoids of intraductal papillary mucinous neoplasms

Abstract Pancreatic cancer is the third leading cause of cancer-related deaths in the United States. There is an unmet need to develop strategies to detect pancreatic cancer at an early, operable stage and prevent its progression. Intraductal papillary mucinous neoplasms (IPMNs) are cystic pancreatic cancer precursors that comprise nearly 50% of pancreatic cysts detected incidentally via computed tomography (CT) scans. Since IPMNs can progress from low- and moderate-grade dysplasia and invasion, the study of these lesions offers a prime opportunity to develop early detection and prevention strategies. Organoids are an ideal preclinical platform to study IPMNs, and the objective of the current investigation was to establish the first living biobank of IPMN tumor organoids. IPMN tumors and adjacent normal pancreatic tissues were harvested from 15 patients undergoing pancreatic surgical resection at Moffitt Cancer Center &amp; Research Institute (Tampa, FL) between 2017 and 2019. Following immunohistopathologic analysis of primary tissues, organoid cultures were generated, expanded, and cryopreserved. Furthermore, organoid cultures were generated from cryopreserved tissues as well. Count and size of the organoids over time was determined via the Image-Pro Premier 3D Version digital platform. Genomic characterization of the organoids was performed through DNA fingerprinting, and a subset of cases were sequenced. The success rates of organoid generation from IPMN tumor and adjacent normal pancreatic tissues were 81% and 87%, respectively. IPMN organoids derived from different IPMN subtypes tissues showed different morphologies in vitro, with the low- and moderate-grade pancreatobiliary subtypes showing the highest proliferation rates. This model has potential to provide new opportunities to unveil mechanisms of IPMN progression to invasion and to shed insight into novel biomarkers for detection and targets for chemoprevention. Citation Format: Dayana Reverón, Francisca Beato, Gina DeNicola, Antonio Ortiz, Barbara Centeno, Kun Jiang, Daniel Jeong, Mokenge Malafa, Pamela Hodul, Kaleena Deszi, Jennifer Permuth, Jason Fleming. Establishing a living biobank of patient-derived organoids of intraductal papillary mucinous neoplasms [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C46.

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.

Molecular and clinical patterns of local progression in the pancreatic remnant following resection of pancreatic intraductal papillary mucinous neoplasm (IPMN)

Intraductal papillary mucinous neoplasms (IPMN) are pancreatic cystic lesions that can progress to invasive carcinoma. Consensus guidelines indicate surgery for IPMN at high risk of malignant progression, as assessed by specific radiological and clinical criteria, whereas an active radiological surveillance is recommended for IPMN at low risk of malignancy. The management of IPMN is further complicated by the risk of developing a distinct new cyst or a ductal adenocarcinoma in the remnant pancreas, either synchronously or metachronously. Several studies therefore investigated local progression in the remnant pancreas following partial pancreatic resection for IPMN and whether an unstable epithelium at risk for malignant degeneration may exist. Understanding the biological mechanisms behind progression of IPMN will help in identifying patients that would benefit from the resection of the entire pancreas.

No Cell Left Unturned: Intraductal Papillary Mucinous Neoplasm Heterogeneity.

Intraductal papillary mucinous neoplasm (IPMN) is a pancreatic cancer precursor lesion with established genetic features, but the cellular ecosystem of these tumors remains to be fully characterized. This study utilizes single-cell RNA sequencing to describe the dynamic landscape of epithelial, immune, and stromal cells during IPMN progression to invasive cancer.See related article by Bernard et al., p. 2194.

Abstract 3121: Characterization of immune profiling of pancreatic intraductal papillary mucinous neoplasm using multiplex immunofluorescence and image analysis approaches

Abstract Pancreatic intraductal papillary mucinous neoplasms (IPMN) are cystic mucin-secreting tumors that arise within the pancreatic ductal system and are considered precursor lesions of pancreatic ductal adenocarcinoma. Profiling the immune infiltrate of IPMNs is essential to understand the immune mechanisms associated with the progression of IPMN. The aim of this study was to characterize the immune profiling of IPMN. We examined 31 formalin-fixed and paraffin-embedded tumor samples from surgically resected IPMN. The diagnostic slides were histologically reviewed by 2 expert pathologists in pancreas and classified as low-grade IPMN (low to intermediate grade dysplasia, N=11), high-grade IPMN (high grade dysplasia, N=18) and IPMN with invasive adenocarcinoma (N=2). Multiplex immunofluorescence (mIF) was used to characterize the immune profiling using two panels: Panel 1: PD-L1, PD1, CD3 (pan T cells), CD8 (T-cytotoxic), CD68 (macrophages), CK (AE1/AE3), DAPI. Panel 2: CD20 (B cells), CD45RO (T-memory), CD57 (NK), Granzyme B (NK and cytotoxic), FOXP3 (T reg), CK (AE1/AE3), DAPI. The slides were scanned using the Vectra multispectral microscope and analyzed by the InForm software (PerkinElmer). We quantified and co-localized immune phenotypes (epithelial cells PD-L1+; Total T-cell lymphocytes; T-cells antigen-experienced; Cytotoxic T-cells; Total macrophages; Macrophages PD-L1+; Total B-cell lymphocytes; Memory T cells; Granzyme B+ cells; Regulatory T cells; NK cells) in low grade dysplasia (LGD), high grade dysplasia (HGD), and invasive carcinoma areas in epithelial and stromal compartments. The Wilcoxon rank sum test or the Wilcoxon singed-rank test was used to test the equality of medians between two independent groups or paired samples, respectively. In all patients, HGD areas showed significantly higher density of macrophages (P= 0.041) and lower density of B-cell lymphocytes (P= 0.028) compared with LGD areas in the epithelial/stromal and epithelial compartments, respectively. Similar differences were observed when patients with high-grade IPMN (n=18) were analyzed for immune infiltrates in the HGD areas compared with LGD areas in the same tumor samples: HGD areas showed significantly higher density of macrophages (P= 0.035) and lower density of B-cell lymphocytes (P= 0.031). Patients with high-grade IPMN had significantly lower densities of B-cell lymphocytes (P= 0.011), T-cell lymphocytes (P= 0.034), and memory T-cells (P= 0.031) in the HGD areas when compared with LGD areas from patients with low-grade IPMN, in the epithelial compartment. No significant differences were found between LGD areas from patients who had high-grade IPMN and LGD areas from patients with low-grade IPMN. In conclusion, we characterized the immune landscape of IPMN and identified immune cell biomarkers associated with progression of IPMN. Citation Format: Luisa M. Solis, Naohiro Uraoka, Edwin Roger Parra, Yu Shen, Wei Wei, Mei Jiang, Barbara Mino, Kajsa Affolter, Courtney L. Scaife, Michele T. Yip-Schneider, C. Max Schmidt, Matthew Firpo, Sean Mulvihill, Eugene J. Koay,, Huamin Wang, Ignacio I. Wistuba, Anirban Maitra, Subrata Sen. Characterization of immune profiling of pancreatic intraductal papillary mucinous neoplasm using multiplex immunofluorescence and image analysis approaches [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3121.

Exact association test for small size sequencing data

BackgroundRecent statistical methods for next generation sequencing (NGS) data have been successfully applied to identifying rare genetic variants associated with certain diseases. However, most commonly used methods (e.g., burden tests and variance-component tests) rely on large sample sizes. Notwithstanding, due to its-still high cost, NGS data is generally restricted to small sample sizes, that cannot be analyzed by most existing methods.MethodsIn this work, we propose a new exact association test for sequencing data that does not require a large sample approximation, which is applicable to both common and rare variants. Our method, based on the Generalized Cochran-Mantel-Haenszel (GCMH) statistic, was applied to NGS datasets from intraductal papillary mucinous neoplasm (IPMN) patients. IPMN is a unique pancreatic cancer subtype that can turn into an invasive and hard-to-treat metastatic disease.ResultsApplication of our method to IPMN data successfully identified susceptible genes associated with progression of IPMN to pancreatic cancer. ConclusionsOur method is expected to identify disease-associated genetic variants more successfully, and corresponding signal pathways, improving our understanding of specific disease’s etiology and prognosis.

Progression Patterns in the Remnant Pancreas after Resection of Non-Invasive or Micro-Invasive Intraductal Papillary Mucinous Neoplasms (IPMN).

Although IPMN are thought to represent a whole-gland disease, segmental resection remains the most frequently performed treatment. We sought to determine the rates, patterns, and predictors of IPMN progression in the pancreatic remnant following segmental resection of noninvasive or microinvasive IPMN. A prospectively maintained database was queried to identify all patients who underwent resection of noninvasive or microinvasive IPMN (≤ 10mm of invasive component) between 1989 and 2015. Progression (recurrence) was defined as either the development of cancer, a new IPMN cystic lesion > 1cm or ≥ 50% increase in the diameter of residual IPMN lesions in the remnant. Univariate and multivariate cox regression models were created to determine predictors of progression. A total of 319 patients underwent resection for noninvasive and microinvasive IPMN. The median age was 68, 53% had branch-duct (BD) IPMN, and 6% had microinvasive disease. After a median follow-up of 42months, 71 patients (22%) experienced IPMN progression. Within this group of 71 patients, 11 (16% of recurrence) developed invasive cancer in the pancreatic remnant after a median of 28months. Twelve patients (17%) experienced progression > 5years following initial resection. On multivariate analysis, a distal location of the initial lesion was associated with an increased risk of progression (multivariate hazards ratio = 2.43, confidence interval 1.47-4.0, p < 0.001). In this study, 22% of patients had disease progression following resection of noninvasive or microinvasive IPMN; 16% of these progressions represented invasive disease. These patients represent a high-risk group and should undergo long-term radiographic surveillance.

Simple Detection of Telomere Fusions in Pancreatic Cancer, Intraductal Papillary Mucinous Neoplasm, and Pancreatic Cyst Fluid

Telomere end-to-end fusions are an important source of chromosomal instability that arise in cells with critically shortened telomeres. We developed a nested real-time quantitative PCR method for telomere fusion detection in pancreatic ductal adenocarcinomas, intraductal papillary mucinous neoplasms (IPMNs), and IPMN cyst fluids. Ninety-one pancreatic cancer cell lines and xenograft samples, 93 IPMNs, and 93 surgically aspirated IPMN cyst fluid samples were analyzed. The association between telomere shortening, telomerase activity, and telomere fusion detection was evaluated. Telomere fusions were detected in 56 of 91 pancreatic cancers (61.5%). Telomere fusion-positive cell lines had significantly shorter telomere lengths than fusion-negative lines (P=0.003). Telomere fusions were undetectable in normal pancreas or IPMNs with low-grade dysplasia (0.0%) and were detected in IPMN with high-grade dysplasia (HGD; 48.0%) (P<0.001). In IPMN cyst fluids, telomere fusions were more frequent in IPMNs with HGD (26.9%) or associated invasive cancer (42.9%) than IPMN with intermediate-grade dysplasia (15.4%) or low-grade dysplasia (0%) (P=0.025). Telomerase activity levels were higher in cyst fluids with fusions than in those without (P=0.0414). Cyst fluid telomere fusion status was an independent predictor of HGD/invasive cancer by multivariate analysis (odds ratio, 6.23; 95% CI, 1.61-28.0). Telomere fusions are detected in later stages of IPMN progression and can serve as a marker for predicting the presence of HGD and/or invasive cancer.

Prognostic significance of E-cadherin and ZEB1 expression in intraductal papillary mucinous neoplasm

There is an urgent need to investigate the genetic changes that occur in intraductal papillary mucinous neoplasm (IPMN), which is a well-known precursor of pancreatic cancer. In this study, gene expression profiling was performed by removing unwanted variation to determine the differentially expressed genes (DEGs) associated with malignant progression of IPMN. Among the identified DEGs, zinc finger E-box binding homeobox 1 (ZEB1) and E-cadherin, a crucial regulator of epithelial-to-mesenchymal transition (EMT), was validated among identified DEGs.A total of 76 fresh-frozen tissues were used for gene expression profiling and formalin-fixed, paraffin-embedded blocks from 87 patients were obtained for immunohistochemical analysis. Loss of E-cadherin expression (p = 0.023, odd ratio [OR] = 4.923) and expression of ZEB1 in stromal cells (stromal ZEB1, p < 0.001, OR = 26.800) were significantly correlated with degree of dysplasia. The hazard of death was significantly increased in patients with loss of E-cadherin expression (hazard ratio [HR] = 13.718, p = 0.004), expression of epithelial ZEB1 (HR = 19.117, p = 0.001), and stromal ZEB1 (HR = 6.373, p = 0.043).Based on the results of this study, loss of E-cadherin and expression of stromal ZEB1 are associated with increased risk of malignant progression. Epithelial and stromal ZEB1, as well as E-cadherin may be strong predictors of survival in patients with IPMN. Our finding suggests that these EMT markers may be utilized as potential prognosticators and may be used to improve and personalize treatment of IPMN.