Management of Locally Advanced Pancreatic Cancer: Results of an International Survey of Current Practice.

OBJECTIVE: The aim of this study was to investigate surgeon preferences for the management of patients with locally advanced pancreatic cancer (LAPC). BACKGROUND: Select patients with LAPC may become candidates for curative resection following neoadjuvant therapy, and recent reports of survival are encouraging. Yet the optimal management approach remains unclear. METHODS: An extensive electronic survey was systematically distributed by email to an international cohort of pancreas surgeons. Data collected included practice characteristics, management preferences, attitudes regarding contraindications to surgery, and 6 clinical vignettes of patients that ultimately received a margin negative resection (with detailed videos of post-neoadjuvant imaging) to assess propensity for surgical exploration if resection status is not known. RESULTS: A total of 153 eligible responses were received from 4 continents. Median duration of practice is 12 years (interquartile range 6-20) and 77% work in a university setting. Most surgeons (86%) are considered high volume (>10 resections/yr), 33% offer a minimally-invasive approach, and 50% offer arterial resections in select patients. Most (72%) always recommend neoadjuvant chemotherapy, and 65% prefer FOLFIRINOX. Preferences for the duration of chemotherapy varied widely: 39% prefer ≥2 months, 43% prefer ≥4 months, and 11% prefer ≥6 months. Forty-one percent frequently recommend neoadjuvant radiotherapy, and 53% prefer 5 to 6 weeks of chemoradiation. The proportion of surgeons favoring exploration following neoadjuvant varied extensively across 5 vignettes of LAPC, from 14% to 53%. In a vignette of oligometastatic liver metastases, 31% would offer exploration if a favorable therapy response is observed. CONCLUSIONS: In an international cohort of pancreas surgeons, there is substantial variation in management preferences, perceived contraindications to surgery, and the propensity to consider exploration in LAPC. These results emphasize the importance of a robust and nuanced multidisciplinary discussion for each patient, and suggest an evolving concept of "resectability."

Hedgehog signaling promotes angiogenesis directly and indirectly in pancreatic cancer.

INTRODUCTION: The inhibition of Hedgehog (Hh) signaling in pancreatic ductal adenocarcinoma (PDAC) reduces desmoplasia and promotes increased vascularity. In contrast to these findings, the Hh ligand Sonic Hedgehog (SHH) is a potent proangiogenic factor in non-tumor models. The aim of this study was to determine the molecular mechanisms by which SHH affects the tumor stroma and angiogenesis. METHODS: Mice bearing three different xenografted human PDAC (n = 5/group) were treated with neutralizing antibodies to SHH. After treatment for 7 days, tumors were evaluated and the expression of 38 pro- and antiangiogenic factors was assessed in the tumor cells and their stroma. The effect of SHH on the regulation of pro- and antiangiogenic factors in fibroblasts and its impact on endothelial cells was then further assessed in in vitro model systems. RESULTS: Inhibition of SHH affected tumor growth, stromal content, and vascularity. Its effect on the Hh signaling pathway was restricted to the stromal compartment of the three cancers. SHH-stimulated angiogenesis indirectly through the reduction of antiangiogenic THBS2 and TIMP2 in stromal cells. An additional direct effect of SHH on endothelial cells depended on the presence of VEGF. CONCLUSION: Inhibition of Hh signaling reduces tumor vascularity, suggesting that Hh plays a role in the maintenance or formation of the tumor vasculature. Whether the reduction in tumor growth and viability seen in the epithelium is a direct consequence of Hh pathway inhibition, or indirectly caused by its effect on the stroma and vasculature, remains to be evaluated.

Loss of Trefoil Factor 2 From Pancreatic Duct Glands Promotes Formation of Intraductal Papillary Mucinous Neoplasms in Mice.

BACKGROUND & AIMS: 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 a progenitor niche for the ductal epithelium; they express gastric mucins and have characteristics of side-branch IPMNs. We investigated whether PDGs are a precursor compartment for IPMNs 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. METHODS: We obtained pancreatectomy specimens from 20 patients with chronic pancreatitis, 13 with low-grade side-branch IPMNs, 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-KRASG12D (KC) mice were bred with TFF2-knockout mice to generate KC/Tff2-/- and KC/Tff2+/- mice. Pancreata were collected and histologically analyzed for formation of IPMN, pancreatic intraepithelial neoplasias, and PDAC, in addition to proliferation and protein expression. Human pancreatic ductal epithelial cells and PDAC cell lines were transfected with vectors to overexpress or knock down TFF2 or SMAD4. RESULTS: Histologic analysis of human samples revealed gastric-type IPMN to comprise 2 molecularly distinct layers: a basal crypt segment that expressed TFF2 and overlying papillary projections. Proliferation occurred predominantly in the PDG-containing basal segments. Mitochondrial mutation mapping revealed a 97% match between the profiles of proliferating PDG cells and their overlying nonproliferative IPMN cells. In contrast to KC mice, 2-month-old KC/Tff2+/- and KC/Tff2-/- mice developed prominent papillary structures in the duct epithelium with cystic metaplasia of the PDG, which resembled human IPMN; these expressed gastric mucins (MUC5AC and MUC6), but not the intestinal mucin MUC2. KC/TFF2-knockout mice developed a greater number and higher grade of pancreatic intraepithelial neoplasias than KC mice, and 1 mouse developed an invasive adenocarcinoma. Expression of TFF2 reduced proliferation of PDAC cells 3-fold; this effect required up-regulation and activation of SMAD4. We found expression of TFF2 to be down-regulated in human PDAC by hypermethylation of its promoter. CONCLUSIONS: In histologic analyses of human IPMNs, we found PDGs to form the basal segment and possibly serve as a progenitor compartment. TFF2 has tumor-suppressor activity in the mouse pancreas and prevents formation of mucinous neoplasms.

A Size-Selective Intracellular Delivery Platform.

Identifying and separating a subpopulation of cells from a heterogeneous mixture are essential elements of biological research. Current approaches require detailed knowledge of unique cell surface properties of the target cell population. A method is described that exploits size differences of cells to facilitate selective intracellular delivery using a high throughput microfluidic device. Cells traversing a constriction within this device undergo a transient disruption of the cell membrane that allows for cytoplasmic delivery of cargo. Unique constriction widths allow for optimization of delivery to cells of different sizes. For example, a 4 µm wide constriction is effective for delivery of cargo to primary human T-cells that have an average diameter of 6.7 µm. In contrast, a 6 or 7 µm wide constriction is best for large pancreatic cancer cell lines BxPc3 (10.8 µm) and PANC-1 (12.3 µm). These small differences in cell diameter are sufficient to allow for selective delivery of cargo to pancreatic cancer cells within a heterogeneous mixture containing T-cells. The application of this approach is demonstrated by selectively delivering dextran-conjugated fluorophores to circulating tumor cells in patient blood allowing for their subsequent isolation and genomic characterization.

Management of the Primary Tumor and Limited Metastases in Patients With Metastatic Pancreatic Cancer.

New combinations of cytotoxic chemotherapy have been proven to increase response rates and survival times compared with single-agent gemcitabine for patients with metastatic pancreatic cancer. These responses have been dramatic for a subset of patients, therefore raising questions about the management of limited metastatic disease with surgery or other ablative methods. Similarly, for patients having a complete radiographic response to chemotherapy in the metastatic compartment, whether to consider local therapy in the form of radiation or surgery for the primary tumor is now an appropriate question. Therefore, collaboration among experts in surgery, medical oncology, and radiation oncology has led to the development of guiding principles for local therapies to the primary intact pancreatic tumor for patients with limited metastatic disease and those who have had a significant response after systemic therapy.

Pancreatic adenocarcinoma, version 2.2014: featured updates to the NCCN guidelines.

The NCCN Guidelines for Pancreatic Adenocarcinoma discuss the diagnosis and management of adenocarcinomas of the exocrine pancreas and are intended to assist with clinical decision-making. These NCCN Guidelines Insights summarize major discussion points from the 2014 NCCN Pancreatic Adenocarcinoma Panel meeting. The panel discussion focused mainly on the management of borderline resectable and locally advanced disease. In particular, the panel discussed the definition of borderline resectable disease, role of neoadjuvant therapy in borderline disease, role of chemoradiation in locally advanced disease, and potential role of newer, more active chemotherapy regimens in both settings.

Cbl and Cbl-b ubiquitin ligases are essential for intestinal epithelial stem cell maintenance.

Receptor tyrosine kinases (RTKs) control stem cell maintenance vs. differentiation decisions. Casitas B-lineage lymphoma (CBL) family ubiquitin ligases are negative regulators of RTKs, but their stem cell regulatory roles remain unclear. Here, we show that Lgr5+ intestinal stem cell (ISC)-specific inducible Cbl-knockout (KO) on a Cblb null mouse background (iDKO) induced rapid loss of the Lgr5 Hi ISCs with transient expansion of the Lgr5 Lo transit-amplifying population. LacZ-based lineage tracing revealed increased ISC commitment toward enterocyte and goblet cell fate at the expense of Paneth cells. Functionally, Cbl/Cblb iDKO impaired the recovery from radiation-induced intestinal epithelial injury. In vitro, Cbl/Cblb iDKO led to inability to maintain intestinal organoids. Single-cell RNA sequencing in organoids identified Akt-mTOR (mammalian target of rapamycin) pathway hyperactivation upon iDKO, and pharmacological Akt-mTOR axis inhibition rescued the iDKO defects. Our results demonstrate a requirement for Cbl/Cblb in the maintenance of ISCs by fine-tuning the Akt-mTOR axis to balance stem cell maintenance vs. commitment to differentiation.

Updated long-term outcomes and prognostic factors for patients with unresectable locally advanced pancreatic cancer treated with intraoperative radiotherapy at the Massachusetts General Hospital, 1978 to 2010.

BACKGROUND: In the current study, the authors evaluated long-term outcomes, intraoperative radiotherapy (IORT)-related toxicity, and prognostic factors for overall survival (OS) among patients with unresectable locally advanced pancreatic cancer (LAPC) who received IORT as part of their treatment at the Massachusetts General Hospital (MGH). METHODS: Medical records were reviewed for 194 consecutive patients with unresectable LAPC who were treated with IORT at MGH between 1978 and 2010. OS was calculated using the Kaplan-Meier method. Prognostic factors were evaluated at the univariate level by the log-rank test and at the multivariate level by the Cox proportional hazards model. Rates of disease progression and treatment toxicity were calculated. RESULTS: The 1-year, 2-year, and 3-year survival rates were 49%, 16%, and 6%, respectively. Six patients (3%) survived for > 5 years. The median OS was 12.0 months. Among 183 patients with known post-IORT disease status, the 2-year local progression-free survival and distant metastasis-free survival rates were 41% and 28%, respectively. On multivariate analysis, an IORT applicator diameter ≤ 8 cm (hazards ratio [HR], 0.51; 95% confidence interval [95% CI], 0.30-0.84 [P = .009]), a Charlson age-comorbidity index ≤ 3 (HR, 0.47; 95% CI, 0.31-0.73 [P = .001]), and receipt of chemotherapy (HR, 0.46; 95% CI, 0.33-0.66 [P < .001]) predicted improved OS. The median OS for patients with all 3 positive prognostic factors was 21.2 months. CONCLUSIONS: Well-selected patients with LAPC with small tumors and low Charlson age-comorbidity indices can achieve good long-term survival outcomes with a treatment regimen that incorporates chemotherapy and IORT.

Branch duct intraductal papillary mucinous neoplasms: does cyst size change the tip of the scale? A critical analysis of the revised international consensus guidelines in a large single-institutional series.

OBJECTIVE: The aim of this study was to critically analyze the safety of the revised guidelines, with focus on cyst size and worrisome features in the management of BD-IPMN. BACKGROUND: The Sendai guidelines for management of branch duct (BD) intraductal papillary mucinous neoplasm (IPMN) espouse safety of observation of asymptomatic cysts smaller than 3 cm without nodules (Sendai negative). Revised international consensus guidelines published in 2012 suggest a still more conservative approach, even for lesions of 3 cm or larger. By contrast, 2 recent studies have challenged the safety of both guidelines, describing invasive carcinoma or carcinoma in situ in 67% of BD-IPMN smaller than 3 cm and in 25% of "Sendai-negative" BD-IPMN. METHODS AND RESULTS: Review of a prospective database identified 563 patients with BD-IPMN. A total of 240 patients underwent surgical resection (152 at the time of diagnosis and 88 after being initially followed); the remaining 323 have been managed by observation with median follow-up of 60 months. No patient developed unresectable BD-IPMN carcinoma during follow-up. Invasive cancer arising in BD-IPMN was found in 23 patients of the entire cohort (4%), and an additional 21 patients (3.7%) had or developed concurrent pancreatic ductal adenocarcinoma. According to the revised guidelines, 76% of resected BD-IPMN with carcinoma in situ and 95% of resected BD-IPMN with invasive cancer had high-risk stigmata or worrisome features. The risk of high-grade dysplasia in nonworrisome lesions smaller than 3 cm was 6.5%, but when the threshold was raised to greater than 3 cm, it was 8.8%, and 1 case of invasive carcinoma was found. CONCLUSIONS: Expectant management of BD-IPMN following the old guidelines is safe, whereas caution is advised for larger lesions, even in the absence of worrisome features.

FOLFIRINOX in locally advanced pancreatic cancer: the Massachusetts General Hospital Cancer Center experience.

The objective of our retrospective institutional experience is to report the overall response rate, R0 resection rate, progression-free survival, and safety/toxicity of neoadjuvant FOLFIRINOX (5-fluorouracil [5-FU], oxaliplatin, irinotecan, and leucovorin) and chemoradiation in patients with locally advanced pancreatic cancer (LAPC). Patients with LAPC treated with FOLFIRINOX were identified via the Massachusetts General Hospital Cancer Center pharmacy database. Demographic information, clinical characteristics, and safety/tolerability data were compiled. Formal radiographic review was performed to determine overall response rates (ORRs). Twenty-two patients with LAPC began treatment with FOLFIRINOX between July 2010 and February 2012. The ORR was 27.3%, and the median progression-free survival was 11.7 months. Five of 22 patients were able to undergo R0 resections following neoadjuvant FOLFIRINOX and chemoradiation. Three of the five patients have experienced distant recurrence within 5 months. Thirty-two percent of patients required at least one emergency department visit or hospitalization while being treated with FOLFIRINOX. FOLFIRINOX possesses substantial activity in patients with LAPC. The use of FOLFIRINOX was associated with conversion to resectability in >20% of patients. However, the recurrences following R0 resection in three of five patients and the toxicities observed with the use of this regimen raise important questions about how to best treat patients with LAPC.

Isolation and characterization of centroacinar/terminal ductal progenitor cells in adult mouse pancreas.

The question of whether dedicated progenitor cells exist in adult vertebrate pancreas remains controversial. Centroacinar cells and terminal duct (CA/TD) cells lie at the junction between peripheral acinar cells and the adjacent ductal epithelium, and are frequently included among cell types proposed as candidate pancreatic progenitors. However these cells have not previously been isolated in a manner that allows formal assessment of their progenitor capacities. We have found that a subset of adult CA/TD cells are characterized by high levels of ALDH1 enzymatic activity, related to high-level expression of both Aldh1a1 and Aldh1a7. This allows their isolation by FACS using a fluorogenic ALDH1 substrate. FACS-isolated CA/TD cells are relatively depleted of transcripts associated with differentiated pancreatic cell types. In contrast, they are markedly enriched for transcripts encoding Sca1, Sdf1, c-Met, Nestin, and Sox9, markers previously associated with progenitor populations in embryonic pancreas and other tissues. FACS-sorted CA/TD cells are uniquely able to form self-renewing "pancreatospheres" in suspension culture, even when plated at clonal density. These spheres display a capacity for spontaneous endocrine and exocrine differentiation, as well as glucose-responsive insulin secretion. In addition, when injected into cultured embryonic dorsal pancreatic buds, these adult cells display a unique capacity to contribute to both the embryonic endocrine and exocrine lineages. Finally, these cells demonstrate dramatic expansion in the setting of chronic epithelial injury. These findings suggest that CA/TD cells are indeed capable of progenitor function and may contribute to the maintenance of tissue homeostasis in adult mouse pancreas.

Cbl and Cbl-b Ubiquitin Ligases are Essential for Intestinal Epithelial Stem Cell Maintenance.

Among the signaling pathways that control the stem cell self-renewal and maintenance vs. acquisition of differentiated cell fates, those mediated by receptor tyrosine kinase (RTK) activation are well established as key players. CBL family ubiquitin ligases are negative regulators of RTKs but their physiological roles in regulating stem cell behaviors are unclear. While hematopoietic Cbl/Cblb knockout (KO) leads to a myeloproliferative disease due to expansion and reduced quiescence of hematopoietic stem cells, mammary epithelial KO led to stunted mammary gland development due to mammary stem cell depletion. Here, we examined the impact of inducible Cbl/Cblb double-KO (iDKO) selectively in the Lgr5-defined intestinal stem cell (ISC) compartment. Cbl/Cblb iDKO led to rapid loss of the Lgr5 Hi ISC pool with a concomitant transient expansion of the Lgr5 Lo transit amplifying population. LacZ reporter-based lineage tracing showed increased ISC commitment to differentiation, with propensity towards enterocyte and goblet cell fate at the expense of Paneth cells. Functionally, Cbl/Cblb iDKO impaired the recovery from radiation-induced intestinal epithelial injury. In vitro , Cbl/Cblb iDKO led to inability to maintain intestinal organoids. Single cell RNAseq analysis of organoids revealed Akt-mTOR pathway hyperactivation in iDKO ISCs and progeny cells, and pharmacological inhibition of the Akt-mTOR axis rescued the organoid maintenance and propagation defects. Our results demonstrate a requirement for Cbl/Cblb in the maintenance of ISCs by fine tuning the Akt-mTOR axis to balance stem cell maintenance vs. commitment to differentiation.

Intraductal papillary mucinous neoplasms: does a family history of pancreatic cancer matter?

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. Extra-pancreatic 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.

Pancreatic Adenocarcinoma, version 2.2012: featured updates to the NCCN Guidelines.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pancreatic Adenocarcinoma discuss the workup and management of tumors of the exocrine pancreas. These NCCN Guidelines Insights provide a summary and explanation of major changes to the 2012 NCCN Guidelines for Pancreatic Adenocarcinoma. The panel made 3 significant updates to the guidelines: 1) more detail was added regarding multiphase CT techniques for diagnosis and staging of pancreatic cancer, and pancreas protocol MRI was added as an emerging alternative to CT; 2) the use of a fluoropyrimidine plus oxaliplatin (e.g., 5-FU/leucovorin/oxaliplatin or capecitabine/oxaliplatin) was added as an acceptable chemotherapy combination for patients with advanced or metastatic disease and good performance status as a category 2B recommendation; and 3) the panel developed new recommendations concerning surgical technique and pathologic analysis and reporting.

Prognosis of invasive intraductal papillary mucinous neoplasm depends on histological and precursor epithelial subtypes.

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 associated with worse overall survival, not significantly different from that of PDAC (HR 0.85; 95% CI 0.53 to 1.36). Colloid and oncocytic carcinomas arose only from intestinal- and oncocytic-type IPMNs, respectively, and were mostly of the main-duct type, whereas tubular adenocarcinomas primarily originated in the gastric background, which was often associated with branch-duct IPMN. Overall survival of patients with invasive adenocarcinomas arising from gastric-type IPMN was significantly worse than that of patients with non-gastric-type IPMN (p=0.016). CONCLUSIONS: Tubular, colloid and oncocytic invasive IPMNs have varying prognosis, and arise from different epithelial subtypes. Colloid and oncocytic types have markedly improved biology, whereas the tubular type has a course that resembles PDAC. Analysis of these subtypes indicates that the background epithelium plays an equally, if not more, important role in defining the biology and prognosis of invasive IPMNs.

Neutrophil granulocyte derived MMP-9 is a VEGF independent functional component of the angiogenic switch in pancreatic ductal adenocarcinoma.

BACKGROUND: Vascular endothelial growth factor (VEGF) that is secreted by tumor cells plays a key role in angiogenesis. Matrix metalloproteinase 9 (MMP-9) is produced by inflammatory cells, such as stromal granulocytes (PMN), remodels the extracellular matrix and is known to promote angiogenesis indirectly by interacting with VEGF. The aim of this study was to determine the role of PMN-derived MMP-9, its interaction with VEGF, and the efficacy of anti-angiogenic therapy targeting MMP-9 with oral Doxycycline and VEGF with Bevacizumab in pancreatic cancer (PDAC). METHODOLOGY/PRINCIPAL FINDINGS: Inhibitors to MMP-9 (Doxycycline) and VEGF (Bevacizumab) were used alone or in combination in an in vitro angiogenesis assay to test their effect on angiogenesis caused by MMP-9, VEGF, PMN and PDAC cells. In an in vivo model of xenografted PDAC, treatment effects after 14 days under monotherapy with oral Doxycycline or Bevacizumab and a combination of both were evaluated. In vitro, PMN-derived MMP-9 had a direct and strong proangiogenic effect that was independent and additive to PDAC-derived VEGF. Complete inhibition of angiogenesis required the inhibition of VEGF and MMP-9. In vivo, co-localization of MMP-9, PMN and vasculature was observed. MMP inhibition with oral Doxycycline alone resulted in a significant decrease in PDAC growth and mean vascular density comparable to VEGF inhibition alone. CONCLUSIONS/SIGNIFICANCE: PMN derived MMP-9 acts as a potent, direct and VEGF independent angiogenic factor in the context of PDAC. MMP-9 inhibition is as effective as VEGF inhibition. Targeting MMP-9 in addition to VEGF is therefore likely to be important for successful anti-angiogenic treatment in pancreatic cancer.

Pancreatic duct glands are distinct ductal compartments that react to chronic injury and mediate Shh-induced metaplasia.

BACKGROUND & AIMS: Pancreatic intraepithelial neoplasia (PanIN) are pancreatic cancer precursor lesions of unclear origin and significance. PanIN aberrantly express sonic hedgehog (Shh), an initiator of pancreatic cancer, and gastrointestinal mucins. A majority of PanIN are thought to arise from ducts. We identified a novel ductal compartment that is gathered in gland-like outpouches (pancreatic duct glands [PDG]) of major ducts and characterized its role in injury and metaplasia. METHODS: The ductal system was analyzed in normal pancreata and chronic pancreatitis in humans and mice. Anatomy was assessed by serial hematoxylin and eosin sections and scanning electron microscopy of corrosion casts. Expression of mucins and developmental genes and proliferation were assessed by immunohistochemistry or real-time quantitative polymerase chain reaction. Effects of Shh on ductal cells were investigated by exposure to Shh in vitro and transgenic misexpression in vivo. RESULTS: Three-dimensional analysis revealed blind-ending outpouches of ducts in murine and human pancreata. These PDG are morphologically and molecularly distinct from normal ducts; even in normal pancreata they display PanIN and metaplastic features, such as expression of Shh and gastric mucins. They express other developmental genes, such as Pdx-1 and Hes-1. In injury, Shh is up-regulated along with gastric mucins. Expansion of the PDG compartment results in a mucinous metaplasia. Shh promotes this transformation in vitro and in vivo. CONCLUSIONS: PDG are distinct gland-like mucinous compartments with a distinct molecular signature. In response to injury, PDG undergo an Shh-mediated mucinous gastrointestinal metaplasia with PanIN-like features. PDG may provide a link between Shh, mucinous metaplasia, and neoplasia.

Invasive intraductal papillary mucinous carcinomas of the pancreas: predictors of survival and the role of lymph node ratio.

INTRODUCTION: Intraductal papillary mucinous neoplasms (IPMNs) are being increasingly recognized, and often harbor cancer. Lymph node metastases are an important prognostic factor for patients with invasive intraductal papillary carcinoma (I-IPMC), but the role of lymph node ratio (LNR) in predicting survival after surgery for I-IPMC is unknown. METHODS: The combined databases from the Surgical Department of Massachusetts General Hospital of Boston and the University of Verona were queried. We retrospectively reviewed clinical and pathologic data of all patients with resected, pathologically confirmed, I-IPMC between 1990 and 2007. Univariate and multivariate analysis were performed. RESULTS: I-IPMCs were diagnosed in 104 patients (55 males and 49 females), median age was 69 years. Recurrent disease was identified in 49 patients (47.1%) and the median 5-year disease specific survival (DSS) was 60.1%. The median number of resected/evaluated nodes was 15 (range, 5-60). There were 60 (57.7%) patients who had negative lymph nodes (N0), whereas 44 (42.3%) had lymph node metastases (N1). Patients with lymph node metastases had a shorter 5-year DSS (28.9%) compared with patients with negative lymph nodes (80.3%; P < 0.05) As the LNR increased, 5-year DSS decreased (LNR = 0, 86.5%; LNR >0 to 0.2, 34.4%; LNR >0.2, 11.1%; P < 0.05). On multivariate analysis, LNR, the presence of a family history of pancreatic cancer and a preoperative value of Ca 19.9 > 37 U/L were significant predictors of survival (P < 0.05). CONCLUSIONS: Lymph node ratio is a strong predictor of survival after resection for invasive intraductal papillary mucinous carcinoma.

Mucin-producing neoplasms of the pancreas: an analysis of distinguishing clinical and epidemiologic characteristics.

BACKGROUND & AIMS: Mucin-producing neoplasms (MPNs) of the pancreas include mucinous cystic neoplasms (MCNs) and main-duct, branch-duct, and combined intraductal papillary mucinous neoplasms (IPMNs). MCNs and branch-duct IPMNs are frequently confused; it is unclear whether main-duct, combined, and branch-duct IPMNs are a different spectrum of the same disease. We evaluated their clinical and epidemiologic characteristics. METHODS: Patients who underwent resection for histologically confirmed MPNs were identified (N = 557); specimens were reviewed and eventually reclassified. RESULTS: One hundred sixty-eight patients (30%) had MCNs, 159 (28.5%) had branch-duct IPMNs, 149 (27%) had combined IPMNs, and 81 (14.5%) had main-duct IPMNs. Patients with MCNs were significantly younger and almost exclusively women; 44% of patients with main-duct or combined IPMNs and 57% of those with branch-duct IPMNs were women. MCNs were single lesions located in the distal pancreas (95%); 11% were invasive. IPMNs were more frequently found in the proximal pancreas; invasive cancer was found in 11%, 42%, and 48% of branch-duct, combined, and main-duct IPMNs, respectively (P = .001). Patients with invasive MCN and those with combined and main-duct IPMNs were older than those with noninvasive tumors. The 5-year disease-specific survival rate approached 100% for patients with noninvasive MPNs. The rates for those with invasive cancer were 58%, 56%, 51%, and 64% for invasive MCNs, branch-duct IPMNs, main-duct IPMNs, and combined IPMNs, respectively. CONCLUSIONS: MPNs comprise 3 different neoplasms: MCNs, branch-duct IPMNs, and main-duct IPMNs, including the combined type. These tumors have specific clinical, epidemiologic, and morphologic features that allow a reasonable degree of accuracy in preoperative diagnosis.

Incidental pancreatic cysts: do we really know what we are watching?

BACKGROUND: Most cystic neoplasms of the pancreas (CNPs) are incidentally discovered. Their management continues to be debated and preoperative diagnosis is often inaccurate. METHODS: Retrospective review of 330 patients with incidentally discovered CNPs. Preoperative and final histological diagnoses were correlated. RESULTS: 41% (136/330) of patients were operated on at diagnosis. 50 patients underwent resection for a presumed branch-duct (Bd) intraductal papillary mucinous neoplasm (IPMN), which was confirmed in only 64% (32/50); of the remaining patients, 20% had main-duct involvement. Mucinous cystic neoplasm was the preoperative diagnosis in 30/136 patients, histologic examination was confirmatory in only 60% (18/30). Most lesions presumed to be main-duct or combined IPMNs or serous cystadenomas were confirmed as such after resection (15/16 and 11/12, respectively). Multifocality was not only associated with Bd-IPMN, and 5% of all cysts were non-neoplastic. Overall, in only 68% of cases did the preoperative and histological diagnoses match. CONCLUSIONS: In an experienced, high-volume center, preoperative diagnosis was incorrect in one-third of incidentally discovered CNPs who underwent resection. Of particular concern, 20% of presumed Bd-IPMN had a main-duct component. Conversely, 5% of resected cysts were not even neoplastic. Clearly, better diagnostic methods are needed to aid in formulating appropriate treatment strategies.