Invasive Pancreatic Adenocarcinoma Research Articles

An In Vitro Three-Dimensional Organotypic Model to Analyze Peripancreatic Fat Invasion in Pancreatic Cancer: A Culture System Based on Collagen Gel Embedding.

Three-dimensional culture systems reflect biological environments better than conventional two-dimensional culture. Additionally, three-dimensional culture is a strong experimental tool to analyze direct interactions between cancer cells and stromal cells in vitro. Herein, we describe protocols for an organotypic fat invasion model that is a novel culturing system mimicking the extrapancreatic invasion of pancreatic adenocarcinoma (PDAC). This novel model is based on the collagen I gel embedding method and enables us to analyze the functional and histological interactions between cancer cells and adipose tissue.

Murine Models of Pancreatitis Leading to the Development of Pancreatic Cancer.

Chronic or repeated episodes of acute pancreatic inflammation, or pancreatitis, are risk factors for the development of pancreatic cancer. Pancreatic cancer is characterized by a strong fibro-inflammatory tumor microenvironment. In pancreatitis, the same fibro-inflammatory reaction is observed concurrently with a loss of normal pancreatic cells. Mouse models are commonly employed to study the progression of pancreatitis and pancreatic cancer, with genetic and pharmacological tools used to elucidate cellular and acellular interactions within pancreatic tumors. Described in this article is a protocol for using KrasG12D ; Pdx1-Cre (KC) mice stimulated with caerulein, a small oligopeptide that increases secretion of digestive enzymes, as a model for pancreatitis. KRAS is mutated in 90-95% of the tumors in patients with pancreatic cancer. The combination of this mutation with an inflammatory stimulus accelerates the development of pancreatic cancer. The protocol detailed in this report follows the progression of disease in KC mice from pancreatic intraepithelial neoplasias to invasive pancreatic adenocarcinoma. © 2018 by John Wiley & Sons, Inc.

Attenuated FOLFIRINOX in the salvage treatment of gemcitabine-refractory advanced pancreatic cancer: a phase II study

BackgroundCombination therapy with oxaliplatin, irinotecan, fluorouracil, and leucovorin (FOLFIRINOX) chemotherapy drastically improves survival of advanced pancreatic cancer patients. However, the efficacy of FOLFIRINOX as a second-line treatment after gemcitabine failure has not been tested prospectively. We investigated the feasibility and safety of attenuated FOLFIRINOX in patients with gemcitabine-refractory advanced pancreatic cancer.MethodsA multicenter phase II prospective open-label, single-arm study was conducted at 14 hospitals. Patients with histologically proven invasive ductal pancreatic adenocarcinoma, a measurable or evaluable lesion, Eastern Cooperative Oncology Group performance status 0 or 1, adequate organ function, and aged 19 years or older were eligible. Attenuated FOLFIRINOX consisted of oxaliplatin 65 mg/m2, irinotecan 135 mg/m2, and leucovorin 400 mg/m2 injected intravenously on day 1 and 5-fluorouracil 2000 mg/m2 continuously infused intravenously over 46 h on days 1–2, repeated every 2 weeks. The primary endpoint was progression-free survival from the initiation of FOLFIRINOX. Secondary endpoints were the objective response rate, disease control rate, overall survival, safety, and tolerability. We estimated overall survival and progression-free survival using the Kaplan–Meier methods.ResultsWe enrolled 39 patients from 14 institutions. The objective response rate was 10.3%, while the disease control rate was 64.1%. The 6-month and 1-year overall survival rates were 59.0% and 15.4%, respectively. Median progression-free survival and overall survival were 3.8 months (95% confidence interval [CI] 1.5–6.0 months) and 8.5 months (95% CI 5.6–11.4 months), respectively. Grade 3 or 4 adverse events were neutropenia (41.0%), nausea (10.3%), anorexia (10.3%), anemia (7.7%), mucositis (7.7%), pneumonia/pleural effusion (5.1%), and fatigue (5.1%). One treatment-related death attributable to septic shock occurred.ConclusionAttenuated FOLFIRINOX may be promising as a second-line therapy for gemcitabine-refractory pancreatic cancer.

AB051. P022. Vein invasion in pancreatic adenocarcinoma is a topography: vein resection in pancreaticoduodenectomy is worthy while

Background: Portomesenteric venous resection (PDVR) during pancreaticoduodenectomy (PD) was supported by view that venous invasion was triggered by tumor location but argued by view that venous invasion was indicating more aggressive tumor biology. This study analyzes venous invasion in pancreatic cancer meaning tumor topography or tumor biology by collecting clinical data.

Extrapancreatic perineural invasion in pancreatic adenocarcinoma.

Pancreatic ductal adenocarcinoma continues to be a highly lethal disease, despite advances in modern medicine. Curative surgical options continue to carry significant morbidity and offer little improvement in overall 5-year survival. Currently, imaging plays an essential role in the pre-operative evaluation of patients who are undergoing evaluation for resection. However, some pancreatic cancers have particularly aggressive biology, despite appearing resectable by conventional imaging criteria. Imaging biomarkers that serve as surrogates for tumors with such aggressive phenotype have been recently described, namely duodenal invasion and extrapancreatic perineural invasion. In this pictorial review, we will summarize key concepts of extrapancreatic perineural invasion, describe its association with a poor prognosis, and highlight the role of imaging in its detection.

Invasive Pancreatic Adenocarcinoma Arising in Intraductal Papillary Mucinous Neoplasm of Heterotopic Pancreatic Origin Located in the Stomach

Invasive Pancreatic Adenocarcinoma Arising in Intraductal Papillary Mucinous Neoplasm of Heterotopic Pancreatic Origin Located in the Stomach

PAP/REG3A favors perineural invasion in pancreatic adenocarcinoma and serves as a prognostic marker.

Pancreatic ductal adenocarcinoma (PDA) is a fatal and insidious malignant disease for which clinicians' tools are restricted by the current limits in knowledge of how tumor and stromal cells act during the disease. Among PDA hallmarks, neural remodeling (NR) and perineural invasion (PNI) drastically influence quality of life and patient survival. Indeed, NR and PNI are associated with neuropathic pain and metastasis, respectively, both of which impact clinicians' decisions and therapeutic options. The aim of this study was to determine the impact and clinical relevance of the peritumoral microenvironment, through pancreatitis-associated protein (PAP/REG3A) expression, on PNI in pancreatic cancer. First, we demonstrated that, in PDA, PAP/REG3A is produced by inflamed acinar cells from the peritumoral microenvironment and then enhances the migratory and invasive abilities of cancer cells. More specifically, using perineural ex vivo assays we revealed that PAP/REG3A favors PNI through activation of the JAK/STAT signaling pathway in cancer cells. Finally, we analyzed the level of PAP/REG3A in blood from healthy donors or patients with PDA from three independent cohorts. Patients with high levels of PAP/REG3A had overall shorter survival as well as poor surgical outcomes with reduced disease-free survival. Our study provides a rationale for using the PAP/REG3A level as a biomarker to improve pancreatic cancer prognosis. It also suggests that therapeutic targeting of PAP/REG3A activity in PDA could limit tumor cell aggressiveness and PNI.

Abstract 4128: Anti-angiogenic and anti-metastatic activities of juglone in pancreatic cancer cells

Abstract Pancreatic cancer is the fourth leading cause of cancer related deaths in the US. The late diagnosis, early metastasis and poor survival rate make this disease lethal. This current study was designed to examine the effect of juglone, 5 hydroxy-1, 4-naphthoquinone in modulating the angiogenic and metastatic potential of pancreatic cancer cells in vitro, using the MIA Paca-2 human pancreatic cancer cell line. Juglone is a natural quinoid abundantly found abundantly in plants of Juglandacea family. To understand the anti-angiogenic and anti-metastatic properties of juglone, expression of markers related to angiogenesis were measured by Western blot or ELISA and the effect on ability of cancer cells to migrate and invade after treatment was analyzed by transwell invasion and migration assay, wound healing assay, and in vitro tube formation assay in human umbilical vein endothelial cells. The Akt pathway is highly upregulated and is responsible for the regulation of various biological processes in pancreatic cancer cells including proliferation, growth, survival and angiogenesis. Akt activation is also associated with regulation of key angiogenic markers such as, VEGF (Vascular Endothelial Growth Factor) and HIF-1 (Hypoxia Inducible Factor). Upon treatment of pancreatic cancer cells with juglone, reduced expression of serine-phosphorylated Akt expression was observed. Juglone inhibited metastasis of pancreatic cancer cells as indicated by the results of cell migration, invasion and wound healing assay. Juglone treatment also downregulated the levels of VEGF and HIF-1α. Significantly, it was found that juglone inhibited pancreatic cancer cell motility, migratory and invading capabilities. These findings suggest that Akt inhibitors such as juglone possess ability to attenuate the aggressiveness of pancreatic cancer cells and can be used as a novel anti-cancer agent to prevent metastasis of highly invasive pancreatic adenocarcinomas. Citation Format: Namrata Karki, Frank Greenway, William Hansel, Sita Aggarwal, Jack N. Losso. Anti-angiogenic and anti-metastatic activities of juglone in pancreatic cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4128.

Low Rates of Malignancy and Mortality in Asymptomatic Patients With Suspected Neoplastic Pancreatic Cysts Beyond 5Years of Surveillance.

The 2015 American Gastroenterological Association guidelines recommend discontinuation of surveillance of pancreatic cysts after 5 years, although there are limited data to support this recommendation. We aimed to determine the rate of pancreatic cancer development from neoplastic pancreatic cysts after 5 years of surveillance. We performed a retrospective multicenter study, collecting data from 310 patients with asymptomatic suspected neoplastic pancreatic cysts, identified by endoscopic ultrasound from January 2002 to June 2010 at 4 medical centers in California. All patients were followed up for 5 years or more (median, 87 mo; range, 60-189 mo). Data were used to calculate the risk for pancreatic cancer and all-cause mortality. Three patients (1%) developed invasive pancreatic adenocarcinoma. Based on American Gastroenterological Association high-risk features (cyst size > 3 cm, dilated pancreatic duct, mural nodule), risks for cancer were 0%, 1%, and 15% for patients with 0, 1, or 2 high-risk features, respectively. Mortality from nonpancreatic causes was 8-fold higher than mortality from pancreatic cancer after more than 5 years of surveillance. There is a very low risk of malignant transformation of asymptomatic neoplastic pancreatic cysts after 5 years. Patients with pancreatic lesions and 0 or 1 high-risk feature have a less than 1% risk of developing pancreatic cancer, therefore discontinuation of surveillance can be considered for select patients. Patients with neoplastic pancreatic cysts with 2 high-risk features have a 15% risk of subsequent pancreatic cancer, therefore surgery or continued surveillance should be considered.

Abstract 2355: Marrow-derived macrophages mediate invasion of pancreatic adenocarcinoma by RET activation

Abstract Introduction: Perineural invasion of cancer cells (CPNI) is found in most patients with pancreatic adenocarcinomas (PDAs). Although the presence of M2 macrophages in the perineural environment has been associated with shortened survival rates in PDA patients, the mechanism underlying this phenomenon has not been elucidated. It has been suggested that secretion of the RET ligand glial-derived neurotrophic factor (GDNF) by M2 macrophages causes cancerous RET-expressing cells to migrate along affected nerves. This concept, however, has not been demonstrated in vivo. This study was aimed at understanding the contribution of macrophages to perineural invasion for in vivo models of PDA, and to characterize the role of the GDNF-RET axis in this unique microenvironmental niche. Methods: Immunohistochemical analysis of PDA specimens of a novel Pdx-1-Cre/KrasG12D /p53R172H (KPC) mouse model, revealed that CD163+ (M2) endoneurial macrophages (EMΦs) predominate the endoneural space of invaded nerves. In a bone marrow transplant (BMT) from CX3CRGFP/+ mice, a 23- fold increase in the recruitment of GFP+ macrophages to the perineural space was witnessed as compared to GFP- cells, indicating recruitment of bone marrow- derived macrophages to the perineural niche, rather than resident tissue macrophages. A BMT from CCR2-/- mice lacking macrophage recruitment capacity resulted in a 6-fold decrease of the invasion severity score, and a 2.5-fold decrease in perineural invasion index. Analysis by fluorescence microscopy indicated that EMΦs expressed higher levels of GDNF compared to EMΦs in premalignant lesion and normal controls. In order to differentiate between the contributions of GDNF secreted by nerves to the invasion presses and its secretion from recruited M2 macrophages, we performed a BMT from GDNF+/- mice. The BMT led to a 1.5-fold improvement in both the invasion severity score and the perineural invasion index. Similarly, mice treated with PP1, a RET receptor inhibitor, caused a 1.5-fold decrease in the invasion severity score, and a 1.3-fold decrease in the perineural invasion index. Finally, xenografts of PDAC cells, in which RET was silenced using siRNA, resulted in a 3.5-fold decrease in the invasion severity score and a 3.2-fold decrease in the perineural invasion index. Discussion: Taken together, our results suggest a paracrine response between bone marrow-derived tumor-associated EMΦs and PDA cells. This loop probably orchestrates the formation of cancer nerve invasion. Further studies using novel transgenic animal models aimed at specifying the specific molecular signals that induce disease invasion and proliferation in the perineural microenvironment are needed. Citation Format: Moran Amit, Shorook Na'ara, Yoav Binenbaum, Ziv Gil. Marrow-derived macrophages mediate invasion of pancreatic adenocarcinoma by RET activation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2355. doi:10.1158/1538-7445.AM2015-2355

International comparison of treatment and short-term survival for older patients with pancreatic cancer.

e20527 Background: A significant proportion of pancreatic cancer patients is aged 70 years or more at diagnosis. The aim of this study was to compare treatment and survival for pancreatic cancer patients aged 70 years and older treated at Moffitt Cancer Center, Tampa (Florida, US) versus in the Netherlands. Methods: All age-eligible patients with invasive pancreatic adenocarcinoma diagnosed between 2008 and 2012 were identified. Results were stratified for stage. Treatment (neo-adjuvant, surgery, adjuvant and palliative treatment) and short-term survival at 1 year were compared, and where appropriate adjusted (sex, age, grade and year) or stratified according to age, period and type of hospital in the Netherlands (academic, teaching or non-teaching). Results: In total, 2728 patients were included (307 Moffitt, 2421 Netherlands). Stratified according to stage, there were no significant differences in age, sex or grade. Neo-adjuvant chemoradiation was more often administrated at Moffitt (17.7% versus 0.6%; ...

Anti-inflammatory macrophages activate invasion in pancreatic adenocarcinoma by increasing the MMP9 and ADAM8 expression

Patients with chronic pancreatitis with local inflammation have high risk for pancreatic cancer. The aim of this study was to examine the role of the inflammatory cells in the invasion of pancreatic cancer cells, focusing on the involvement of a disintegrin and metalloproteinase 8 (ADAM8) and matrix metalloproteinase 9 (MMP9) proteins. ADAM8 expression is associated with worse survival of pancreatic cancer patients. Monocytes from healthy donors were differentiated into macrophages. Pancreatic adenocarcinoma cells were cultured either alone or with differentiated macrophages. The cancer cell migration rate in Matrigel was measured by imaging fluorescently stained cells for 24 h. After invasion, cells were sorted into CD14 positive/negative macrophages and cancer cells with magnetic separation. The expression of ADAM8 and MMP9 was measured by the real-time PCR. Protein-level expression of ADAM8 and MMP9 was analyzed by Western blotting. In two series, siRNA technique was used to reduce either ADAM8 or MMP9 expression in the cancer cells. The coculture with macrophages increased cancer cell migration rate in Matrigel, and increased ADAM8 and MMP9 mRNA expression and protein level in the cancer cells. Reduction of ADAM8 expression with siRNA in the cancer cells decreased macrophage-induced migration rate of the cancer cells from 11.7±0.3 μm/h to 9.0±0.2 μm/h (p<0.01), and reduction of MMP9 expression decreased the migration rate to 10.1±0.2 μm/h (p<0.01). Anti-inflammatory macrophages increase pancreatic cancer cell migration rate in basement membrane matrix by inducing ADAM8 and MMP9 expression in cancer cells, thereby possibly enhancing the invasiveness of cancer.

Vascular Endothelial Growth Factor, a Novel and Highly Accurate Pancreatic Fluid Biomarker for Serous Pancreatic Cysts

Mucinous pancreatic cysts (intraductal papillary mucinous neoplasm and mucinous cystic neoplasm) have the potential to progress to invasive pancreatic adenocarcinoma, presenting an opportunity for early detection, prevention, and cure. Serous cystic neoplasms (SCN) have no malignant potential, but can mimic mucinous pancreatic cysts on imaging. Therefore, identification of biomarkers that can distinguish between cystic lesions is critically important. We hypothesize that vascular endothelial growth factor (VEGF)-A levels in pancreatic fluid correlate with pathologic diagnosis. Pancreatic cyst/duct fluid samples were prospectively collected from patients undergoing pancreatic resection and correlated with surgical pathology. VEGF levels were detected by ELISA. VEGF-A and VEGF receptor 2 expression in pancreatic tissue was localized by immunohistochemistry. Genetic alterations of the von Hippel-Lindau gene were determined by targeted next-generation sequencing. Eighty-seven patients met inclusion criteria for enrollment. Final pathologic diagnoses included pseudocyst (n = 9), SCN (n = 17), mucinous cystic neoplasm (n = 24), low/moderate grade intraductal papillary mucinous neoplasm (n = 16), high-grade/invasive intraductal papillary mucinous neoplasm (n = 10), and pancreatic ductal adenocarcinoma (n = 11). VEGF-A was significantly upregulated in SCN cyst fluid compared with all other diagnoses (p < 0.0001). With a cut-off of 8,500 pg/mL, VEGF-A has 100% sensitivity and 97% specificity as an SCN biomarker. VEGF-A and VEGF receptor 2 are overexpressed in SCN cyst tissue. VEGF-C was also significantly elevated in SCN cyst fluid (p < 0.0001). With a cut-off set at 200 pg/mL, VEGF-C identifies SCN with 100% sensitivity and 90% specificity. The presence of a von Hippel-Lindau mutation in SCN cyst tissue correlates with elevated cyst fluid VEGF levels. This is the first report of a cyst fluid protein biomarker that can positively identify SCN. The ability to distinguish SCN from premalignant/malignant pancreatic cysts can spare the cost and risk of surveillance and surgical intervention in select patients.

Abstract 190: Sulindac inhibits pancreatic carcinogenesis in LSL-KrasG12D-LSL-Trp53R172H-Pdx-1-Cre mice by suppressing aldo-keto reductase family 1B10 (AKR1B10).

Abstract Sulindac inhibits carcinogenesis via the mechanism that appears beyond cyclooxygenase inhibition. Recently sulindac has been identified as competitive inhibitors of aldo-keto reductase family 1B10 (AKR1B10). AKR1B10 is involved in the process of carbonyls, farnesyl and geranylgeranyl as well as retinal metabolisms, and these metabolic activities are important to carcinogenesis. However, there is no evidence on if inhibition of pancreatic carcinogenesis by sulindac is via inhibition of AKR1B10 and protein prenylation (i.e., Kras protein). To determine the effect of sulindac on pancreatic carcinogenesis in LSL-KrasG12D-LSL-Trp53R172H-Pdx-1-Cre mice, five-week-old mice were fed with either AIN-93M diet or AIN-93M diet contained 200ppm sulindac (n=20 mice/group). Kaplan-Meier survival analysis with Log-Rank test was performed to analyze the effect of sulindac on animal survival from the development of pancreatic carcinoma. The results showed that average animal survival in LSL-KrasG12D-LSL-Trp53R172H-Pdx-1-Cre mice was 143.7 ± 8.8 days; and with the sulindac 200ppm treatment, animal survival significantly increased to 168.0 ± 8.8 days (p&amp;lt;0.005). Extensively histopathological analyses revealed that 90% of mice developed malignant pancreatic carcinomas, of which 10% invasive pancreatic adenocarcinoma had metastasis to liver and lymph nodes. With 200ppm sulindac treatment, incidence of pancreatic cancer and its metastasis were significantly reduced to 56% and 0%, respectively (P&amp;lt;0.01). Immunchemical analysis showed that sulindac treatment significantly decreased Ki-67-labeled cell proliferation, increased caspase-3-labeled cell apoptosis, and suppressed phosphorylated ERK1/2. In vitro mouse pancreatic carcinoma cells derived from the LSL-KrasG12D/+-LSL-Trp53R172/+-Pdx-1-Cre mice were further treated with sulindac and revealed that sulindac inhibited AKR1B10 enzyme activity, suppressed Kras and HDJ2 protein prenylation, and further inhibited phosphylation of C-raf, ERK1/2 and MEK1/2. Similar to sulindac treatment, siRNA-silencing AKR1B10 expression resulted in a significant reduction of Kras protein prenylation and its downstream signals. Our results demonstrate that sulindac inhibits pancreatic carcinogenesis, mainly via inhibition of kras protein prenylation and its activated signals by targeting AKR1B10. (supported NCI R01 CA164041) Citation Format: Jie Liao, Yeon Tae Chung, Haonan Li, Wanying Zhang, Guang-Yu Yang. Sulindac inhibits pancreatic carcinogenesis in LSL-KrasG12D-LSL-Trp53R172H-Pdx-1-Cre mice by suppressing aldo-keto reductase family 1B10 (AKR1B10). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 190. doi:10.1158/1538-7445.AM2013-190

Proteomic analysis of perineural invasion in pancreatic adenocarcinoma reveals up-regulation of neurosecretory protein VGF in invaded nerves

Proteomic analysis of perineural invasion in pancreatic adenocarcinoma reveals up-regulation of neurosecretory protein VGF in invaded nerves

Diagnostic Accuracy of Imaging Modalities in the Evaluation of Vascular Invasion in Pancreatic Adenocarcinoma: A Meta-Analysis.

BackgroundThe extent of vascular invasion is a key factor determining the resectability of non-metastatic pancreatic adenocarcinoma. The purpose of this study is to determine the diagnostic accuracy of computed tomography (CT), endoscopic ultrasound (EUS), and magnetic resonance imaging (MRI) in the pre-operative evaluation of vascular invasion in pancreatic adenocarcinoma, with surgery as the reference standard.MethodsA search of the MEDLINE database for relevant articles in the English language published between January 2000 and February 2009 was performed. From each study, 2 × 2 tables were obtained, and pooled sensitivity, specificity, positive likelihood ratios, negative likelihood ratios and diagnostic odds ratios were calculated for each modality, along with a summary receiver operating characteristics (SROC) curve.Results16 studies with a total of 797 patients who had surgical assessment of vascular invasion were included in the analysis. Several studies evaluated more than one imaging modality, allowing 24 datasets to be obtained in total. Sensitivity was highest for CT (0.73, 95% CI 0.67 - 0.79), followed by EUS (0.66, 95% CI 0.56 - 0.75) and MRI (0.63, 95% CI 0.48 - 0.77). The specificity for all three imaging modalities was comparable. The diagnostic odds ratios for CT, EUS and MRI were 45.9 (95% CI 18.0 - 117.4), 23.0 (95%CI 9.4 - 56.6), 23.9 (95% CI 5.4 - 105.1) respectively.ConclusionCT was more accurate than EUS and MRI in the evaluation of vascular invasion in pancreatic adenocarcinoma and should be the first line investigation in pre-operative staging.

Mutant TP53 in Duodenal Samples of Pancreatic Juice From Patients With Pancreatic Cancer or High-Grade Dysplasia

Imaging tests can identify patients with pancreatic neoplastic cysts but not microscopic dysplasia. We investigated whether mutant TP53 can be detected in duodenal samples of secretin-stimulated pancreatic juice, and whether this assay can be used to screen for high-grade dysplasia and invasive pancreatic cancer. We determined the prevalence of mutant TP53 in microdissected pancreatic intraepithelial neoplasias (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and invasive adenocarcinomas. TP53 mutations were quantified by digital high-resolution melt-curve analysis and sequencing of secretin-stimulated pancreatic juice samples, collected from duodena of 180 subjects enrolled in Cancer of the Pancreas Screening trials; patients were enrolled because of familial and/or inherited predisposition to pancreatic cancer, or as controls. TP53 mutations were identified in 9.1% of intermediate-grade IPMNs (2 of 22), 17.8% of PanIN-2 (8 of 45), 38.1% of high-grade IPMNs (8 of 21), 47.6% of PanIN-3 (10 of 21), and 75% of invasive pancreatic adenocarcinomas (15 of 20); no TP53 mutations were found in PanIN-1 lesions or low-grade IPMNs. TP53 mutations were detected in duodenal samples of pancreatic juice from 29 of 43 patients with pancreatic ductal adenocarcinoma (67.4% sensitivity; 95% confidence interval, 0.52-0.80) and 4 of 8 patients with high-grade lesions (PanIN-3 and high-grade IPMN). No TP53 mutations were identified in samples from 58 controls or 55 screened individuals without evidence of advanced lesions. We detected mutant TP53 in secretin-stimulated pancreatic juice samples collected from duodena of patients with high-grade dysplasia or invasive pancreatic cancer. Tests for mutant TP53 might be developed to improve the diagnosis of and screening for pancreatic cancer and high-grade dysplasia. Clinical Trial numbers: NCT00438906 and NCT00714701.

Use of the monoclonal antibody PAM4 to differentiate pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis and benign nonmucinous cysts of the pancreas.

188 Background: Previous studies have demonstrated that anti-mucin monoclonal antibody (mAb) PAM4 is highly specific for PDAC and its precursor lesions. To investigate specificity further, we examined the expression of PAM4-reactive mucin in chronic pancreatitis and benign non-mucinous cystic lesions of the pancreas. Methods: A tissue microarray of PDAC (N=14), as well as surgical specimens from chronic pancreatitis (N=32) and benign non-mucinous cystic lesions of the pancreas (N=19), were assessed by immunohistochemistry for expression of the PAM4-reactive mucin, as well as MUC1 (mAb-MA5), MUC4 (mAb-8G7), and CEACAM6 (mAb-MN-15). Results: PAM4-reactive mucin, MUC1, MUC4 and CEACAM6 were expressed in 79% (11/14), 100% (14/14), 86% (12/14) and 100% (14/14) of invasive pancreatic adenocarcinoma. PAM4 only weakly labeled 6% (1/19) of benign non-mucinous cystic lesions, 1 of 15 serous cystadenomas (SCAs) and 0 of 4 cysts with squamous epithelial lining (2 lymphoepithelial cysts, and 2 retention cysts with squamous metaplasia). However, the expression of MUC1, MUC4 and CEACAM6 was detected in 53% (8/15), 0% (0/15) and 13% (2/15) of SCAs, and in 4, 3 and 3 of the 4 cysts with squamous epithelial lining, respectively. PAM4 labeled 19% (6/32) of chronic pancreatitis specimens; however, this PAM4 reactivity was restricted to the PanIN precursor lesions associated with chronic pancreatitis. Inflamed tissue was negative. The expression of MUC1, MUC4 and CEACAM6 was detected in 90% (27/30), 78% (25/32), and 97% (31/32) of chronic pancreatitis. In all of the positively-labeled specimens, the reactivity was present in non-neoplastic inflamed pancreatic tissue in addition to PanIN. Conclusions: The expression of PAM4 was detected in only 6% of benign non-mucinous cystic lesions and in the precursor lesions associated with chronic pancreatitis. These results suggest that PAM4, in contrast to MUC1, MUC4, and CEACAM6, may be useful to differentiate benign non-mucinous cystic lesions of the pancreas and chronic pancreatitis from PDAC. (Supported in part by NIH grant CA096924.)

6556 POSTER Splenic Artery Invasion in Pancreatic Adenocarcinoma of the Body and Tail – a Novel Prognostic Parameter for Patients Selection

6556 POSTER Splenic Artery Invasion in Pancreatic Adenocarcinoma of the Body and Tail – a Novel Prognostic Parameter for Patients Selection

Tissue and Serum microRNAs in the KrasG12D Transgenic Animal Model and in Patients with Pancreatic Cancer

microRNAs (miRs) modulate the expression levels of mRNAs and proteins and can thus contribute to cancer initiation and progression. In addition to their intracelluar function, miRs are released from cells and shed into the circulation. We postulated that circulating miRs could provide insight into pathways altered during cancer progression and may indicate responses to treatment. Here we focus on pancreatic cancer malignant progression. We report that changes in miR expression patterns during progression of normal tissues to invasive pancreatic adenocarcinoma in the p48-Cre/LSL-KrasG12D mouse model mirrors the miR changes observed in human pancreatic cancer tissues. miR-148a/b and miR-375 expression were found decreased whereas miR-10, miR-21, miR-100 and miR-155 were increased when comparing normal tissues, premalignant lesions and invasive carcinoma in the mouse model. Predicted target mRNAs FGFR1 (miR-10) and MLH1 (miR-155) were found downregulated. Quantitation of nine microRNAs in plasma samples from patients distinguished pancreatic cancers from other cancers as well as non-cancerous pancreatic disease. Finally, gemcitabine treatment of control animals and p48-Cre/LSL-KrasG12D animals with pancreatic cancer caused distinct and up to 60-fold changes in circulating miRs that indicate differential drug effects on normal and cancer tissues. These findings support the significance of detecting miRs in the circulation and suggests that circulating miRs could serve as indicators of drug response.