Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly desmoplastic reaction, warra... more Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly desmoplastic reaction, warranting intense cancer–stroma communication. In this study, we interrogated the contribution of the BET family of chromatin adaptors to the cross-talk between PDAC cells and the tumor stroma. Short-term treatment of orthotopic xenograft tumors with CPI203, a small-molecule inhibitor of BET proteins, resulted in broad changes in the expression of genes encoding components of the extracellular matrix (matrisome) in both cancer and stromal cells. Remarkably, more than half of matrisome genes were expressed by cancer cells. In vitro cocultures of PDAC cells and cancer-associated fibroblasts (CAF) demonstrated that matrisome expression was regulated by BET-dependent cancer–CAF cross-talk. Disrupting this cross-talk in vivo resulted in diminished growth of orthotopic patient-derived xenograft tumors, reduced proliferation of cancer cells, and changes in collagen structure consistent with that of...
Patient-derived xenograft (PDX) tumors are powerful tools to study cancer biology. However, the a... more Patient-derived xenograft (PDX) tumors are powerful tools to study cancer biology. However, the ability of PDX tumors to model the biological and histological diversity of pancreatic ductal adenocarcinoma (PDAC) is not well known. In this study, we subcutaneously implanted 133 primary and metastatic PDAC tumors into immunodeficient mice. Fifty-seven tumors were successfully engrafted and even after extensive passaging, the histology of poorly-, moderately-, and well-differentiated tumors was maintained in the PDX models. Moreover, the fibroblast and collagen contents in the stroma of patient tumors were recapitulated in the corresponding PDX models. Analysis of the clinicopathological features of patients revealed xenograft tumor engraftment was associated with lymphovascular invasion (P = 0.001) and worse recurrence-free (median, 7 vs. 16 months, log-rank P = 0.047) and overall survival (median, 13 vs. 21 months, log-rank P = 0.038). Among successful engraftments, median time of growth required for reimplantation into new mice was 151 days. Reflective of the inherent biological diversity between PDX tumors with rapid (<151 days) and slow growth, differences in their growth were maintained during extensive passaging. Rapid growth was additionally associated with lymph node metastasis (P = 0.022). The association of lymphovascular invasion and lymph node metastasis with PDX formation and rapid growth may reflect an underlying biological mechanism that allows these tumors to adapt and grow in a new environment. While the ability of PDX tumors to mimic the cellular and non-cellular features of the parental tumor stroma provides a valuable model to study the interaction of PDAC cells with the tumor microenvironment, the association of
Little is known about the origin of pancreatic intraductal papillary mucinous neoplasms (IPMN). P... more Little is known about the origin of pancreatic intraductal papillary mucinous neoplasms (IPMN). Pancreatic duct glands (PDGs) are gland-like outpouches budding off the main pancreatic ducts that function as progenitor niche for the ductal epithelium; they express gastric mucins and have characteristics of side-branch IPMN. We investigated whether PDGs are a precursor compartment for IPMN and the role of trefoil factor family 2 (TFF2)- a protein expressed by PDGs and the gastric mucosa that are involved in epithelial repair and tumor suppression. We obtained pancreatectomy specimens from 20 patients with chronic pancreatitis, 13 with low-grade side-branch IPMN, and 15 patients with PDAC; histologically normal pancreata were used as controls (n=18). Samples were analyzed by immunohistochemistry to detect TFF1 and TFF2 and cell proliferation. We performed mitochondrial DNA mutational mapping studies to determine the cell lineage and fate of PDG cells. Pdx1-Cre;LSL-KRAS(G12D) (KC) mice ...
Purpose: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) ... more Purpose: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) results from the interplay of genetic and epigenetic events. While the genetic alterations of PDAC have been well characterized, epigenetic pathways regulating PDAC remain, for the most part, elusive. The goal of this study was to identify novel epigenetic regulators contributing to the biology of PDAC. Experimental Design: In vivo pooled shRNA screens targeting 118 epigenetic proteins were performed in two orthotopic PDAC xenograft models. Candidate genes were characterized in 19 human PDAC cell lines, heterotopic xenograft tumor models, and a genetically engineered mouse (GEM) model of PDAC. Gene expression, IHC, and immunoprecipitation experiments were performed to analyze the pathways by which candidate genes contribute to PDAC. Results: In vivo shRNA screens identified BRD2 and BRD3, members of the BET family of chromatin adaptors, as key regulators of PDAC tumor growth. Pharmacolog...
Absorptive and secretory cells of the small intestine are derived from a single population of Lgr... more Absorptive and secretory cells of the small intestine are derived from a single population of Lgr5-expressing stem cells. While key genetic pathways required for differentiation into specific lineages have been defined, epigenetic programs contributing to this process remain poorly characterized. Members of the BET family of chromatin adaptors contain tandem bromodomains that mediate binding to acetylated lysines on target proteins to regulate gene expression. In this study, we demonstrate that mice treated with a small molecule inhibitor of BET bromodomains, CPI203, exhibit greater than 90% decrease in tuft and enteroendocrine cells in both crypts and villi of the small intestine, with no changes observed in goblet or Paneth cells. BET bromodomain inhibition did not alter the abundance of Lgr5-expressing stem cells in crypts, but rather exerted its effects on intermediate progenitors, in part through regulation of Ngn3 expression. When BET bromodomain inhibition was combined with t...
Mucinous cystic neoplasm and intraductal papillary mucinous neoplasm are 2 types of cystic pancre... more Mucinous cystic neoplasm and intraductal papillary mucinous neoplasm are 2 types of cystic pancreatic mucinous tumors, each with its own distinct clinicopathologic features and pathogenetic mechanisms. We report here an unusual pancreatic mucinous neoplasm with features of both a mucinous cystic neoplasm and an intraductal papillary mucinous neoplasm in a 40-year-old woman who underwent total pancreatectomy. The endoscopic retrograde cholangiopancreatogram and gross examination demonstrated a mucin-producing intraductal neoplasm involving the length of the main pancreatic duct, typical of main duct intraductal papillary mucinous neoplasm, but histology of the main duct showed involvement by a biphasic tumor composed of columnar epithelium overlying ovarian-type stroma, characteristic of a mucinous cystic neoplasm. Immunohistochemistry confirmed that the stromal cells expressed estrogen and progesterone receptors, inhibin, and calretinin. Pancreatic mucinous cystic neoplasm involving...
Pancreatic cancer is a lethal disease without effective treatments at present. It ranks as s as 4... more Pancreatic cancer is a lethal disease without effective treatments at present. It ranks as s as 4th and 5th in cancer-related mortality in the western countries and worldwide. Locally advanced pancreatic duct carcinoma (PDAC) and metastatic PDAC, usually found the metastases over liver, peritoneum, or lung, have been shown to be with dismal prognosis. Brain metastasis is a rare entity and most cases reported before were found post-mortem. Intraductal papillary mucinous neoplasms of the pancreas (IPMN) has been deemed as a precursor of PDAC with very slow progression rate. Here we reported a case diagnosed with IPMN-derived PDAC with brain metastasis. After surgeries for PDAC and brain metastasis, subsequent chemotherapy and radiotherapy were also given. One and half year after surgery, this patient is still living with good performance status, which may warrant individualization of therapeutic strategy for PDAC with only brain metastasis.
To evaluate the long-term outcome after surgical resection of sporadic, asymptomatic NF-pNET < 2 ... more To evaluate the long-term outcome after surgical resection of sporadic, asymptomatic NF-pNET < 2 cm, stratifying the results by resection type and histopathologic features. Patients & methods: Patients resected between June 1997 and November 2008 at our institution (minimum follow-up of 60 months) were retrieved from a prospectively maintained electronic database and analyzed retrospectively. Results: Study population consisted of 49 patients (27 females and 22 males), with a median age of 59 years (range 38-61). 31 patients underwent parenchyma-sparing resections (15 enucleations, 15 middle pancreatectomies, 1 spleen-preserving distal pancreatectomies), while 18 patients underwent formal resections (8 pancreaticoduodenectomies, 10 distal pancreactomies with splenectomy). Mean lymph node yielding was 1.35 (0-9) in atypical resections and 19 (7-32) in formal resections (p¼0.0001). Lymph node metastases were found in only one patient undergoing pancreaticoduodenectomy. The median tumor size was 16 mm. 48 tumors were G1, one was G2, none was G3 (2010 WHO classification). The final pathologic report showed microscopic local invasion (perineural invasion, lymph vascular invasion or fat invasion) in 8 patients. At a median followup of 80 months (60-193), 4 patients died of other causes, 4 were lost to follow-up the remaining 37 patients did not develop recurrence and are alive and disease-free. Conclusion: Long-term outcome of surgically resected asymptomatic sporadic NF-pNET < 2 cm is excellent. Atypical resections with limited lymph node dissection may be oncologically adequate. Microscopic local invasion did not impact on the natural history of the disease.
Background-The malignant potential of intraductal mucinous neoplasm of the pancreas (IPMN) is ass... more Background-The malignant potential of intraductal mucinous neoplasm of the pancreas (IPMN) is associated closely with main pancreatic duct (MPD) involvement. Because mixed-type IPMN is thought to have the same malignant potential as that of main-duct (MD)-IPMN, resection is recommended; however, the biological nature of mixed-type IPMN with only minimal involvement of MPD (min-mix-IPMN) may be different. Methods-A prospective database of 404 resected IPMNs was re-reviewed to subclassify mixedtype IPMNs. We defined min-mix-IPMN as absence of gross abnormalities (except for dilatation) of MPD and noncircumferential microscopic involvement of MPD limited to few sections. Results-We identified 46 min-mix-IPMNs, 163 IPMNs with extensive involvement of MPD (ex-mix-IPMN), 175 branch-duct (BD)-IPMNs, and 20 MD-IPMNs. The majority of min-mix-IPMNs were found incidentally and increased cyst size on surveillance was the leading operative indication. The median diameter of MPD was 2 mm in min-mix-IPMN versus 9 mm in ex-mix-IPMN (P < .0001), and cysts ≥10 mm were present in 62% of ex-mix-IPMNs versus 93% of minmix-IPMNs (P < .0001). Most importantly, the vast majority of min-mix-IPMNs exhibited gastrictype epithelium, similar to BD-IPMNs, whereas intestinal-type epithelium was present in half of ex-mix-IPMNs, similar to MD-IPMNs. The prevalence of high-grade lesions was less in min-mix-Reprint requests:
Objectives-To describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) wi... more Objectives-To describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) with predominant involvement of the main pancreatic duct (MPD), analyzing predictors for survival and recurrence. Background-IPMNs involving the MPD harbor a high likelihood of malignancy and different biological features. The appropriateness of including cases with minimal noncircumferential MPD involvement has been challenged because these show clinicopathological features that are similar to branch duct IPMN. Accordingly, their exclusion has led to a redefinition of MPD IPMN (MD-IPMN). Methods-Retrospective review of resected MD-IPMN from 1990 to 2013. All slides were reviewed by a single pancreatic pathologist and classified on the basis of epithelial type and invasive component. Results-A total of 223 patients underwent resection for IPMN involving the MPD. Of these, 50 were excluded because of minimal MPD involvement. Among the 173 patients analyzed, median age was 68 years and 55% were males. Predominant epithelial phenotype was intestinal (50%). Forty-eight patients (28%) had low-or intermediate-grade dysplasia, whereas 125 (72%) had either high-grade dysplasia (33%) or invasive carcinoma (39%). Of the 67 invasive IPMNs, 39 were tubular carcinomas (58%) and invasion was minimal (<5 mm) in 28 (42%). The 5-year overall survival rate was 69% and the disease-specific survival rate was 83%. The estimated recurrence rate at 10 years was 25%. Size and type of the invasive component, lymph node positivity, and a positive resection margin were predictors for both survival and recurrence (P < 0.05). Conclusions-MD-IPMN is mainly intestinal-type and malignant. After resection, it has a very favorable prognosis, especially in the absence of macroscopic invasive carcinoma.
Objective-The prognosis of ampullary adenocarcinoma (AA) is usually favorable; however, a subset ... more Objective-The prognosis of ampullary adenocarcinoma (AA) is usually favorable; however, a subset of AA have poor biology and outcomes similar to pancreatic cancer. Patients in this subset will have early recurrence and death usually within two years. To date there are no genetic markers to identify these patients. This study identifies the high-risk subset of AA, and evaluates the mutational status of KRAS in predicting poor outcome. Methods-The tumor registry of an academic center was reviewed for data on surgically managed patients with AA. KRAS genotypes were determined for these patients using a PCRbased assay on clinical specimens. ANOVA and χ 2 tests were used to categorize continuous and categorical variables. Univariate and multivariate survival analyses were performed using Kaplan-Meier (KM) and Cox methods, respectively. Results-146 patients were identified with AA between 1982 and 2008. After stringent pathologic review, 97 patients were confirmed with AA of which 75 had available tissue specimens for analysis. Genotyping revealed, 67% were wild-type (KRAS WT) and 33% were mutant for KRAS. Patients with KRAS G12D , the most common mutational genotype, had significantly poorer median survival (62 months, mo) compared to KRAS non-G12D mutants (median survival not reached, mean 145 mo) and KRAS WT patients (155 mo), p = 0.05. Patients with survival ≤ 30 mo were labeled 'high-risk'. Of patients with KRAS G12D , 55.6% were in this high-risk subset, compared to only 18% of KRAS WT (p = 0.02) and 31.3% of KRAS non-G12D (p >
Background-Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an import... more Background-Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an important cause of cancer death in the United States. Operative resection remains as the only treatment providing prolonged survival, but even after a curative resection, 5-year survival rates are low. Our aim was to identify the prognostic factors for long-term survival after resection of pancreatic ductal adenocarcinoma related to patients, treatments, and tumor biology. Methods-Retrospective review identified 959 patients who underwent resection of their pancreatic adenocarcinoma between February 1985 and December 2010, of whom 499 were resected before November 2006 and represent the cohort we describe in this study. Patient, tumor, and treatment-related variables were assessed for their associations with 5-and 10-year overall survival. Results-Of the 499 patients, 49% were female and median age was 65 years. The majority of patients had stage IIb disease (60%). Actual 5-year survival after resection of pancreatic adenocarcinoma was 19% (95/499), and actual 10-year survival was 10% (33/329). Significant clinicopathologic factors predicting 5-and 10-year survival were negative margins and negative nodal status. Interestingly, 41% (39/95) of long-term survivors had positive nodes and 24% (23/95) had positive margins. Conclusion-Pancreatic ductal adenocarcinoma demonstrates a very heterogeneous biology, but patients with negative resection margins and node negative cancers are more likely to survive 5 years after resection. However, our series demonstrates that the biology of the cancer rather than simple pathologic factors determine a patient's prognosis. Recently, the American Cancer Society reported that during the last decade overall rates of cancer and cancer death have dropped. 1 This is believed to be largely because of a decrease in cigarette smoking and an increase in cancer screening. Conversely, pancreatic cancer rates are on the rise. 2 This fact, in combination with the dismal prognosis and lack of early detection, make pancreatic cancer a growing concern. Additionally, societal awareness of
onstrate known mutations or polymorphisms. Conclusion: Based upon pedigree evaluation and prelimi... more onstrate known mutations or polymorphisms. Conclusion: Based upon pedigree evaluation and preliminary DNA analysis, we believe that the family members with P/PC carry a novel genetic mutation resulting in hereditary pancreatitis. This mutation is autosomal dominant, expressed with high penetrance, and is part of a unique hereditary syndrome that significantly increases pancreatic cancer risk.
Background/Objectives-The purpose of this study is to compare surgically resected intraductal pap... more Background/Objectives-The purpose of this study is to compare surgically resected intraductal papillary mucinous neoplasms (IPMNs) in patients with and without a family history of pancreatic cancer to gain insight into differences that may suggest the need for differential management. Methods-A retrospective review of patients who underwent resection of an IPMN at the Massachusetts General Hospital (1990-2011) was conducted. Three hundred and twenty-four patients of whom 45 (13.9%) had a family history of pancreatic cancer were identified. Patients with (PFH) and without (NFH) a family history of pancreatic cancer were compared. Results-There were no differences in demographic characteristics between groups. Extrapancreatic malignancies diagnosed prior to the IPMN were more common in those with a PFH (35.6% vs 20.1%, p = 0.03). There were no differences in IPMN characteristics between groups including no difference in the presence of invasive disease (p = 0.55). Concurrent pancreatic ductal adenocarcinomas were more common in those with a PFH (11.1% vs 2.9%, p = 0.02). The survival in the PFH group was marginally lower than the NFH group, a difference found to be attributable to the higher prevalence of extra-pancreatic malignancies. Conclusion-Characteristics of surgically resected IPMNs are not different between patients with and without a family history of pancreatic cancer. Most importantly, the incidence of invasive disease is not different, suggesting that these lesions may not be more aggressive when they occur in the presence of a family history of pancreatic cancer.
Objectives-Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a unique entity w... more Objectives-Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a unique entity with malignant potential. Histologically, pancreatic ductal adenocarcinoma (PDAC) arising in IPMN (intraductal papillary mucinous carcinoma [IPMC]) appears similar to sporadic PDAC; biologically, however, IPMC seems to have a less aggressive clinical course. Little is known about the genetic signature of IPMC. In this study, we describe a novel xenograft model and cell culture created to biologically and genetically characterize these tumors. Methods-Xenograft mice and cell lines were created from IPMC. Global genomic changes were evaluated by cytogenetic analysis and array comparative genomic hybridization. Specific mutations and sonic hedgehog (Shh) pathway activity were examined and xenografts evaluated for sensitivity to anti-Shh therapy. Results-Cytogenetic analysis showed a tetraploid karyotype with multiple aberrations. KRAS and p53 mutations and overexpression of the Shh pathway were identified. Array comparative genomic hybridization revealed multiple chromosomal aberrations comparable with previously published data in IPMNs. Murine xenograft tumors were sensitive to anti-Shh treatment. Conclusions-Characterization of IPMC cell lines and xenografts reveals similarities to previously published data on IPMN. In comparison to PDAC, moreover, these data reveal shared aberrations and distinct genomic changes. Thus, these xenograft model and cell lines may be useful for future preclinical investigations.
Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and interventio... more Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findingsdcompared with pathologic diagnosesd predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.
Introduction-Pancreatic intraductal papillary mucinous neoplasms (IPMN) are now identified with i... more Introduction-Pancreatic intraductal papillary mucinous neoplasms (IPMN) are now identified with increasing frequency. The detection of carcinoma in IPMN is difficult and suffers from high false-positive and false-negative rates, often resulting in inappropriate treatment decisions. Improved detection of malignancy using novel biomarkers may therefore improve diagnostic accuracy. One such promising novel biomarker is Plectin-1 (Plec-1). Methods-Using immunohistochemistry, Plec-1 expression was assayed in benign (low and moderate dysplasia, n=6) as well as malignant IPMN (high-grade dysplasia and invasive carcinoma, n=31) and lymph node metastases from carcinoma arising in IPMN (n=12). Furthermore, cyst fluids from benign (n=3) and malignant IPMN (n=4) were evaluated for Plec-1 expression. Results and discussion-Twenty-six of 31 malignant IPMN and all 12 lymph node metastases were Plec-1 positive. In contrast, only one of six benign IPMN expressed Plec-1. The specificity of Plec-1 in distinguishing malignant IPMN from benign IPMN was 83% and its sensitivity 84%. Furthermore, all (four out of four) cyst fluids from malignant IPMN, but none of the three benign IPMN, were Plec-1 positive. These data support Plec-1 as an excellent biomarker for the early detection of carcinoma arising in IPMN.
Objective-Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recogn... more Objective-Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recognised as a morphologically and biologically heterogeneous group of neoplasms. Less is known about the epithelial subtypes of the precursor IPMN from which these lesions arise. The authors investigate the clinicopathological characteristics and the impact on survival of both the invasive component and its background IPMN. Design and patients-The study cohort comprised 61 patients with invasive IPMN (study group) and 570 patients with pancreatic ductal adenocarcinoma (PDAC, control group) resected at a single institution. Multivariate analyses were performed using a stage-matched Cox proportional hazard model. Results-The histology of invasive components of the IPMN cohort was tubular in 38 (62%), colloid in 16 (26%), and oncocytic in seven (12%). Compared with PDAC, invasive IPMNs were associated with a lower incidence of adverse pathological features and improved mortality by multivariate analysis (HR 0.58; 95% CI 0.39 to 0.86). In subtype analysis, this favourable outcome remained only for colloid and oncocytic carcinomas, while tubular adenocarcinoma was
Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly desmoplastic reaction, warra... more Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly desmoplastic reaction, warranting intense cancer–stroma communication. In this study, we interrogated the contribution of the BET family of chromatin adaptors to the cross-talk between PDAC cells and the tumor stroma. Short-term treatment of orthotopic xenograft tumors with CPI203, a small-molecule inhibitor of BET proteins, resulted in broad changes in the expression of genes encoding components of the extracellular matrix (matrisome) in both cancer and stromal cells. Remarkably, more than half of matrisome genes were expressed by cancer cells. In vitro cocultures of PDAC cells and cancer-associated fibroblasts (CAF) demonstrated that matrisome expression was regulated by BET-dependent cancer–CAF cross-talk. Disrupting this cross-talk in vivo resulted in diminished growth of orthotopic patient-derived xenograft tumors, reduced proliferation of cancer cells, and changes in collagen structure consistent with that of...
Patient-derived xenograft (PDX) tumors are powerful tools to study cancer biology. However, the a... more Patient-derived xenograft (PDX) tumors are powerful tools to study cancer biology. However, the ability of PDX tumors to model the biological and histological diversity of pancreatic ductal adenocarcinoma (PDAC) is not well known. In this study, we subcutaneously implanted 133 primary and metastatic PDAC tumors into immunodeficient mice. Fifty-seven tumors were successfully engrafted and even after extensive passaging, the histology of poorly-, moderately-, and well-differentiated tumors was maintained in the PDX models. Moreover, the fibroblast and collagen contents in the stroma of patient tumors were recapitulated in the corresponding PDX models. Analysis of the clinicopathological features of patients revealed xenograft tumor engraftment was associated with lymphovascular invasion (P = 0.001) and worse recurrence-free (median, 7 vs. 16 months, log-rank P = 0.047) and overall survival (median, 13 vs. 21 months, log-rank P = 0.038). Among successful engraftments, median time of growth required for reimplantation into new mice was 151 days. Reflective of the inherent biological diversity between PDX tumors with rapid (<151 days) and slow growth, differences in their growth were maintained during extensive passaging. Rapid growth was additionally associated with lymph node metastasis (P = 0.022). The association of lymphovascular invasion and lymph node metastasis with PDX formation and rapid growth may reflect an underlying biological mechanism that allows these tumors to adapt and grow in a new environment. While the ability of PDX tumors to mimic the cellular and non-cellular features of the parental tumor stroma provides a valuable model to study the interaction of PDAC cells with the tumor microenvironment, the association of
Little is known about the origin of pancreatic intraductal papillary mucinous neoplasms (IPMN). P... more Little is known about the origin of pancreatic intraductal papillary mucinous neoplasms (IPMN). Pancreatic duct glands (PDGs) are gland-like outpouches budding off the main pancreatic ducts that function as progenitor niche for the ductal epithelium; they express gastric mucins and have characteristics of side-branch IPMN. We investigated whether PDGs are a precursor compartment for IPMN and the role of trefoil factor family 2 (TFF2)- a protein expressed by PDGs and the gastric mucosa that are involved in epithelial repair and tumor suppression. We obtained pancreatectomy specimens from 20 patients with chronic pancreatitis, 13 with low-grade side-branch IPMN, and 15 patients with PDAC; histologically normal pancreata were used as controls (n=18). Samples were analyzed by immunohistochemistry to detect TFF1 and TFF2 and cell proliferation. We performed mitochondrial DNA mutational mapping studies to determine the cell lineage and fate of PDG cells. Pdx1-Cre;LSL-KRAS(G12D) (KC) mice ...
Purpose: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) ... more Purpose: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) results from the interplay of genetic and epigenetic events. While the genetic alterations of PDAC have been well characterized, epigenetic pathways regulating PDAC remain, for the most part, elusive. The goal of this study was to identify novel epigenetic regulators contributing to the biology of PDAC. Experimental Design: In vivo pooled shRNA screens targeting 118 epigenetic proteins were performed in two orthotopic PDAC xenograft models. Candidate genes were characterized in 19 human PDAC cell lines, heterotopic xenograft tumor models, and a genetically engineered mouse (GEM) model of PDAC. Gene expression, IHC, and immunoprecipitation experiments were performed to analyze the pathways by which candidate genes contribute to PDAC. Results: In vivo shRNA screens identified BRD2 and BRD3, members of the BET family of chromatin adaptors, as key regulators of PDAC tumor growth. Pharmacolog...
Absorptive and secretory cells of the small intestine are derived from a single population of Lgr... more Absorptive and secretory cells of the small intestine are derived from a single population of Lgr5-expressing stem cells. While key genetic pathways required for differentiation into specific lineages have been defined, epigenetic programs contributing to this process remain poorly characterized. Members of the BET family of chromatin adaptors contain tandem bromodomains that mediate binding to acetylated lysines on target proteins to regulate gene expression. In this study, we demonstrate that mice treated with a small molecule inhibitor of BET bromodomains, CPI203, exhibit greater than 90% decrease in tuft and enteroendocrine cells in both crypts and villi of the small intestine, with no changes observed in goblet or Paneth cells. BET bromodomain inhibition did not alter the abundance of Lgr5-expressing stem cells in crypts, but rather exerted its effects on intermediate progenitors, in part through regulation of Ngn3 expression. When BET bromodomain inhibition was combined with t...
Mucinous cystic neoplasm and intraductal papillary mucinous neoplasm are 2 types of cystic pancre... more Mucinous cystic neoplasm and intraductal papillary mucinous neoplasm are 2 types of cystic pancreatic mucinous tumors, each with its own distinct clinicopathologic features and pathogenetic mechanisms. We report here an unusual pancreatic mucinous neoplasm with features of both a mucinous cystic neoplasm and an intraductal papillary mucinous neoplasm in a 40-year-old woman who underwent total pancreatectomy. The endoscopic retrograde cholangiopancreatogram and gross examination demonstrated a mucin-producing intraductal neoplasm involving the length of the main pancreatic duct, typical of main duct intraductal papillary mucinous neoplasm, but histology of the main duct showed involvement by a biphasic tumor composed of columnar epithelium overlying ovarian-type stroma, characteristic of a mucinous cystic neoplasm. Immunohistochemistry confirmed that the stromal cells expressed estrogen and progesterone receptors, inhibin, and calretinin. Pancreatic mucinous cystic neoplasm involving...
Pancreatic cancer is a lethal disease without effective treatments at present. It ranks as s as 4... more Pancreatic cancer is a lethal disease without effective treatments at present. It ranks as s as 4th and 5th in cancer-related mortality in the western countries and worldwide. Locally advanced pancreatic duct carcinoma (PDAC) and metastatic PDAC, usually found the metastases over liver, peritoneum, or lung, have been shown to be with dismal prognosis. Brain metastasis is a rare entity and most cases reported before were found post-mortem. Intraductal papillary mucinous neoplasms of the pancreas (IPMN) has been deemed as a precursor of PDAC with very slow progression rate. Here we reported a case diagnosed with IPMN-derived PDAC with brain metastasis. After surgeries for PDAC and brain metastasis, subsequent chemotherapy and radiotherapy were also given. One and half year after surgery, this patient is still living with good performance status, which may warrant individualization of therapeutic strategy for PDAC with only brain metastasis.
To evaluate the long-term outcome after surgical resection of sporadic, asymptomatic NF-pNET < 2 ... more To evaluate the long-term outcome after surgical resection of sporadic, asymptomatic NF-pNET < 2 cm, stratifying the results by resection type and histopathologic features. Patients & methods: Patients resected between June 1997 and November 2008 at our institution (minimum follow-up of 60 months) were retrieved from a prospectively maintained electronic database and analyzed retrospectively. Results: Study population consisted of 49 patients (27 females and 22 males), with a median age of 59 years (range 38-61). 31 patients underwent parenchyma-sparing resections (15 enucleations, 15 middle pancreatectomies, 1 spleen-preserving distal pancreatectomies), while 18 patients underwent formal resections (8 pancreaticoduodenectomies, 10 distal pancreactomies with splenectomy). Mean lymph node yielding was 1.35 (0-9) in atypical resections and 19 (7-32) in formal resections (p¼0.0001). Lymph node metastases were found in only one patient undergoing pancreaticoduodenectomy. The median tumor size was 16 mm. 48 tumors were G1, one was G2, none was G3 (2010 WHO classification). The final pathologic report showed microscopic local invasion (perineural invasion, lymph vascular invasion or fat invasion) in 8 patients. At a median followup of 80 months (60-193), 4 patients died of other causes, 4 were lost to follow-up the remaining 37 patients did not develop recurrence and are alive and disease-free. Conclusion: Long-term outcome of surgically resected asymptomatic sporadic NF-pNET < 2 cm is excellent. Atypical resections with limited lymph node dissection may be oncologically adequate. Microscopic local invasion did not impact on the natural history of the disease.
Background-The malignant potential of intraductal mucinous neoplasm of the pancreas (IPMN) is ass... more Background-The malignant potential of intraductal mucinous neoplasm of the pancreas (IPMN) is associated closely with main pancreatic duct (MPD) involvement. Because mixed-type IPMN is thought to have the same malignant potential as that of main-duct (MD)-IPMN, resection is recommended; however, the biological nature of mixed-type IPMN with only minimal involvement of MPD (min-mix-IPMN) may be different. Methods-A prospective database of 404 resected IPMNs was re-reviewed to subclassify mixedtype IPMNs. We defined min-mix-IPMN as absence of gross abnormalities (except for dilatation) of MPD and noncircumferential microscopic involvement of MPD limited to few sections. Results-We identified 46 min-mix-IPMNs, 163 IPMNs with extensive involvement of MPD (ex-mix-IPMN), 175 branch-duct (BD)-IPMNs, and 20 MD-IPMNs. The majority of min-mix-IPMNs were found incidentally and increased cyst size on surveillance was the leading operative indication. The median diameter of MPD was 2 mm in min-mix-IPMN versus 9 mm in ex-mix-IPMN (P < .0001), and cysts ≥10 mm were present in 62% of ex-mix-IPMNs versus 93% of minmix-IPMNs (P < .0001). Most importantly, the vast majority of min-mix-IPMNs exhibited gastrictype epithelium, similar to BD-IPMNs, whereas intestinal-type epithelium was present in half of ex-mix-IPMNs, similar to MD-IPMNs. The prevalence of high-grade lesions was less in min-mix-Reprint requests:
Objectives-To describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) wi... more Objectives-To describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) with predominant involvement of the main pancreatic duct (MPD), analyzing predictors for survival and recurrence. Background-IPMNs involving the MPD harbor a high likelihood of malignancy and different biological features. The appropriateness of including cases with minimal noncircumferential MPD involvement has been challenged because these show clinicopathological features that are similar to branch duct IPMN. Accordingly, their exclusion has led to a redefinition of MPD IPMN (MD-IPMN). Methods-Retrospective review of resected MD-IPMN from 1990 to 2013. All slides were reviewed by a single pancreatic pathologist and classified on the basis of epithelial type and invasive component. Results-A total of 223 patients underwent resection for IPMN involving the MPD. Of these, 50 were excluded because of minimal MPD involvement. Among the 173 patients analyzed, median age was 68 years and 55% were males. Predominant epithelial phenotype was intestinal (50%). Forty-eight patients (28%) had low-or intermediate-grade dysplasia, whereas 125 (72%) had either high-grade dysplasia (33%) or invasive carcinoma (39%). Of the 67 invasive IPMNs, 39 were tubular carcinomas (58%) and invasion was minimal (<5 mm) in 28 (42%). The 5-year overall survival rate was 69% and the disease-specific survival rate was 83%. The estimated recurrence rate at 10 years was 25%. Size and type of the invasive component, lymph node positivity, and a positive resection margin were predictors for both survival and recurrence (P < 0.05). Conclusions-MD-IPMN is mainly intestinal-type and malignant. After resection, it has a very favorable prognosis, especially in the absence of macroscopic invasive carcinoma.
Objective-The prognosis of ampullary adenocarcinoma (AA) is usually favorable; however, a subset ... more Objective-The prognosis of ampullary adenocarcinoma (AA) is usually favorable; however, a subset of AA have poor biology and outcomes similar to pancreatic cancer. Patients in this subset will have early recurrence and death usually within two years. To date there are no genetic markers to identify these patients. This study identifies the high-risk subset of AA, and evaluates the mutational status of KRAS in predicting poor outcome. Methods-The tumor registry of an academic center was reviewed for data on surgically managed patients with AA. KRAS genotypes were determined for these patients using a PCRbased assay on clinical specimens. ANOVA and χ 2 tests were used to categorize continuous and categorical variables. Univariate and multivariate survival analyses were performed using Kaplan-Meier (KM) and Cox methods, respectively. Results-146 patients were identified with AA between 1982 and 2008. After stringent pathologic review, 97 patients were confirmed with AA of which 75 had available tissue specimens for analysis. Genotyping revealed, 67% were wild-type (KRAS WT) and 33% were mutant for KRAS. Patients with KRAS G12D , the most common mutational genotype, had significantly poorer median survival (62 months, mo) compared to KRAS non-G12D mutants (median survival not reached, mean 145 mo) and KRAS WT patients (155 mo), p = 0.05. Patients with survival ≤ 30 mo were labeled 'high-risk'. Of patients with KRAS G12D , 55.6% were in this high-risk subset, compared to only 18% of KRAS WT (p = 0.02) and 31.3% of KRAS non-G12D (p >
Background-Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an import... more Background-Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an important cause of cancer death in the United States. Operative resection remains as the only treatment providing prolonged survival, but even after a curative resection, 5-year survival rates are low. Our aim was to identify the prognostic factors for long-term survival after resection of pancreatic ductal adenocarcinoma related to patients, treatments, and tumor biology. Methods-Retrospective review identified 959 patients who underwent resection of their pancreatic adenocarcinoma between February 1985 and December 2010, of whom 499 were resected before November 2006 and represent the cohort we describe in this study. Patient, tumor, and treatment-related variables were assessed for their associations with 5-and 10-year overall survival. Results-Of the 499 patients, 49% were female and median age was 65 years. The majority of patients had stage IIb disease (60%). Actual 5-year survival after resection of pancreatic adenocarcinoma was 19% (95/499), and actual 10-year survival was 10% (33/329). Significant clinicopathologic factors predicting 5-and 10-year survival were negative margins and negative nodal status. Interestingly, 41% (39/95) of long-term survivors had positive nodes and 24% (23/95) had positive margins. Conclusion-Pancreatic ductal adenocarcinoma demonstrates a very heterogeneous biology, but patients with negative resection margins and node negative cancers are more likely to survive 5 years after resection. However, our series demonstrates that the biology of the cancer rather than simple pathologic factors determine a patient's prognosis. Recently, the American Cancer Society reported that during the last decade overall rates of cancer and cancer death have dropped. 1 This is believed to be largely because of a decrease in cigarette smoking and an increase in cancer screening. Conversely, pancreatic cancer rates are on the rise. 2 This fact, in combination with the dismal prognosis and lack of early detection, make pancreatic cancer a growing concern. Additionally, societal awareness of
onstrate known mutations or polymorphisms. Conclusion: Based upon pedigree evaluation and prelimi... more onstrate known mutations or polymorphisms. Conclusion: Based upon pedigree evaluation and preliminary DNA analysis, we believe that the family members with P/PC carry a novel genetic mutation resulting in hereditary pancreatitis. This mutation is autosomal dominant, expressed with high penetrance, and is part of a unique hereditary syndrome that significantly increases pancreatic cancer risk.
Background/Objectives-The purpose of this study is to compare surgically resected intraductal pap... more Background/Objectives-The purpose of this study is to compare surgically resected intraductal papillary mucinous neoplasms (IPMNs) in patients with and without a family history of pancreatic cancer to gain insight into differences that may suggest the need for differential management. Methods-A retrospective review of patients who underwent resection of an IPMN at the Massachusetts General Hospital (1990-2011) was conducted. Three hundred and twenty-four patients of whom 45 (13.9%) had a family history of pancreatic cancer were identified. Patients with (PFH) and without (NFH) a family history of pancreatic cancer were compared. Results-There were no differences in demographic characteristics between groups. Extrapancreatic malignancies diagnosed prior to the IPMN were more common in those with a PFH (35.6% vs 20.1%, p = 0.03). There were no differences in IPMN characteristics between groups including no difference in the presence of invasive disease (p = 0.55). Concurrent pancreatic ductal adenocarcinomas were more common in those with a PFH (11.1% vs 2.9%, p = 0.02). The survival in the PFH group was marginally lower than the NFH group, a difference found to be attributable to the higher prevalence of extra-pancreatic malignancies. Conclusion-Characteristics of surgically resected IPMNs are not different between patients with and without a family history of pancreatic cancer. Most importantly, the incidence of invasive disease is not different, suggesting that these lesions may not be more aggressive when they occur in the presence of a family history of pancreatic cancer.
Objectives-Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a unique entity w... more Objectives-Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a unique entity with malignant potential. Histologically, pancreatic ductal adenocarcinoma (PDAC) arising in IPMN (intraductal papillary mucinous carcinoma [IPMC]) appears similar to sporadic PDAC; biologically, however, IPMC seems to have a less aggressive clinical course. Little is known about the genetic signature of IPMC. In this study, we describe a novel xenograft model and cell culture created to biologically and genetically characterize these tumors. Methods-Xenograft mice and cell lines were created from IPMC. Global genomic changes were evaluated by cytogenetic analysis and array comparative genomic hybridization. Specific mutations and sonic hedgehog (Shh) pathway activity were examined and xenografts evaluated for sensitivity to anti-Shh therapy. Results-Cytogenetic analysis showed a tetraploid karyotype with multiple aberrations. KRAS and p53 mutations and overexpression of the Shh pathway were identified. Array comparative genomic hybridization revealed multiple chromosomal aberrations comparable with previously published data in IPMNs. Murine xenograft tumors were sensitive to anti-Shh treatment. Conclusions-Characterization of IPMC cell lines and xenografts reveals similarities to previously published data on IPMN. In comparison to PDAC, moreover, these data reveal shared aberrations and distinct genomic changes. Thus, these xenograft model and cell lines may be useful for future preclinical investigations.
Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and interventio... more Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findingsdcompared with pathologic diagnosesd predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.
Introduction-Pancreatic intraductal papillary mucinous neoplasms (IPMN) are now identified with i... more Introduction-Pancreatic intraductal papillary mucinous neoplasms (IPMN) are now identified with increasing frequency. The detection of carcinoma in IPMN is difficult and suffers from high false-positive and false-negative rates, often resulting in inappropriate treatment decisions. Improved detection of malignancy using novel biomarkers may therefore improve diagnostic accuracy. One such promising novel biomarker is Plectin-1 (Plec-1). Methods-Using immunohistochemistry, Plec-1 expression was assayed in benign (low and moderate dysplasia, n=6) as well as malignant IPMN (high-grade dysplasia and invasive carcinoma, n=31) and lymph node metastases from carcinoma arising in IPMN (n=12). Furthermore, cyst fluids from benign (n=3) and malignant IPMN (n=4) were evaluated for Plec-1 expression. Results and discussion-Twenty-six of 31 malignant IPMN and all 12 lymph node metastases were Plec-1 positive. In contrast, only one of six benign IPMN expressed Plec-1. The specificity of Plec-1 in distinguishing malignant IPMN from benign IPMN was 83% and its sensitivity 84%. Furthermore, all (four out of four) cyst fluids from malignant IPMN, but none of the three benign IPMN, were Plec-1 positive. These data support Plec-1 as an excellent biomarker for the early detection of carcinoma arising in IPMN.
Objective-Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recogn... more Objective-Invasive cancers arising from intraductal papillary mucinous neoplasm (IPMN) are recognised as a morphologically and biologically heterogeneous group of neoplasms. Less is known about the epithelial subtypes of the precursor IPMN from which these lesions arise. The authors investigate the clinicopathological characteristics and the impact on survival of both the invasive component and its background IPMN. Design and patients-The study cohort comprised 61 patients with invasive IPMN (study group) and 570 patients with pancreatic ductal adenocarcinoma (PDAC, control group) resected at a single institution. Multivariate analyses were performed using a stage-matched Cox proportional hazard model. Results-The histology of invasive components of the IPMN cohort was tubular in 38 (62%), colloid in 16 (26%), and oncocytic in seven (12%). Compared with PDAC, invasive IPMNs were associated with a lower incidence of adverse pathological features and improved mortality by multivariate analysis (HR 0.58; 95% CI 0.39 to 0.86). In subtype analysis, this favourable outcome remained only for colloid and oncocytic carcinomas, while tubular adenocarcinoma was
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Papers by Andrew Warshaw