'Artery-first' approaches to pancreatoduodenectomy

BACKGROUND

The technique of pancreatoduodenectomy (PD) has evolved. Previously, non-resectability was determined by involvement of the portal vein-superior mesenteric vein. Because venous resection can be achieved safely and with greater awareness of the prognostic significance of the status of the posteromedial resection margin, non-resectability is now determined by involvement of the superior mesenteric artery (SMA). This change, with a need for early determination of resectability before an irreversible step, has promoted the development of an 'artery-first' approach. The aim of this study was to review, and illustrate, this approach.

METHODS

An electronic search was performed on MEDLINE, Embase and PubMed databases from 1960 to 2011 using both medical subject headings and truncated word searches to identify all published articles that related to this topic.

RESULTS

The search revealed six different surgical approaches that can be considered as 'artery first'. These involved approaching the SMA from the retroperitoneum (posterior approach), the uncinate process (medial uncinate approach), the infracolic region medial to the duodenojejunal flexure (inferior infracolic or mesenteric approach), the infracolic retroperitoneum lateral to the duodenojenunal flexure (left posterior approach), the supracolic region (inferior supracolic approach) and through the lesser sac (superior approach).

CONCLUSION

The six approaches described provide a range of options for the early determination of arterial involvement, depending on the location and size of the tumour, and before the 'point of no return'. Whether these approaches will achieve an increase in the proportion of patients with negative margins, improve locoregional control and increase long-term survival has yet to be determined.

The application of methylation specific electrophoresis (MSE) to DNA methylation analysis of the 5' CpG island of mucin in cancer cells

Background

Methylation of CpG sites in genomic DNA plays an important role in gene regulation and especially in gene silencing. We have reported mechanisms of epigenetic regulation for expression of mucins, which are markers of malignancy potential and early detection of human neoplasms. Epigenetic changes in promoter regions appear to be the first step in expression of mucins. Thus, detection of promoter methylation status is important for early diagnosis of cancer, monitoring of tumor behavior, and evaluating the response of tumors to targeted therapy. However, conventional analytical methods for DNA methylation require a large amount of DNA and have low sensitivity.

Methods

Here, we report a modified version of the bisulfite-DGGE (denaturing gradient gel electrophoresis) using a nested PCR approach. We designated this method as methylation specific electrophoresis (MSE). The MSE method is comprised of the following steps: (a) bisulfite treatment of genomic DNA, (b) amplification of the target DNA by a nested PCR approach and (c) applying to DGGE. To examine whether the MSE method is able to analyze DNA methylation of mucin genes in various samples, we apply it to DNA obtained from state cell lines, ethanol-fixed colonic crypts and human pancreatic juices.

Result

The MSE method greatly decreases the amount of input DNA. The lower detection limit for distinguishing different methylation status is < 0.1% and the detectable minimum amount of DNA is 20 pg, which can be obtained from only a few cells. We also show that MSE can be used for analysis of challenging samples such as human isolated colonic crypts or human pancreatic juices, from which only a small amount of DNA can be extracted.

Conclusions

The MSE method can provide a qualitative information of methylated sequence profile. The MSE method allows sensitive and specific analysis of the DNA methylation pattern of almost any block of multiple CpG sites. The MSE method can be applied to analysis of DNA methylation status in many different clinical samples, and this may facilitate identification of new risk markers.

Definitive radiotherapy for patients with isolated local recurrence of primary resected pancreatic cancer: A retrospective analysis

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Background: Only surgical resection can provide a chance of long-term survival for patients with pancreatic cancer, but loco-regional recurrence has been a major challenge which inevitably results in poor prognosis and loss of patients’ quality of life. Curative reoperation is seldom attainable but has been suggested to have benefits on overall survival. We hypothesized that definitive radiotherapy could offer a good control for the unresectable local recurrence and improve survival. The primary objective of this retrospective analysis is to evaluate the efficacy and tolerability of definitive radiotherapy for patients with isolated locally-recurrent pancreatic cancer.

Methods: A total of 26 patients, who developed local recurrence of primarily resected pancreatic cancer and received radiotherapy between 2000 and 2011, were retrospectively analyzed. The isolated local recurrence was diagnosed with the radiological images (CT/MRI/PET) and tumor marker relapse. The overall survival (OS) and local control rate (LC) were calculated from the start day of radiotherapy and estimated by Kaplan-Meier method. The responses in tumor size and tumor markers were evaluated. The treatment-related toxicity was assessed according to CTC-AE (ver. 4.0).

Results: The median total dose of radiotherapy was 50.4 Gy (range, 39.6–54 Gy). Concurrent chemotherapy consisted of gemcitabine (62%), S-1 (19%), and 5-fluorouracil (4%). At a median follow-up time of 13 months, the 1-year OS and median survival were 75% and 21.6 months, respectively. The 1-year local control rate was 59%. Objective radiological response was not seen. The tumor marker reduction and ≥ 50% reduction were observed in 65% and 12%. Grade≥3 hematological toxicity was seen in 62%. Grade ≥ 3 of acute gastrointestinal toxicity was not observed. At a late phase, Grade 3 ileus observed in one, and Grade 3 gastric bleeding ulcer was seen in one patient.

Conclusions: Definitive radiotherapy resulted in encouraging local control and overall survival for patients with isolated locally-recurrent pancreatic cancer. This treatment strategy should be further evaluated prospectively.

Identification of S-acyl glutathione conjugates of bile acids in human bile by means of LC/ESI-MS

Previous work from this laboratory has reported the biotransformation of bile acids (BA) into the thioester-linked glutathione (GSH) conjugates via the intermediary metabolites formed by BA:CoA ligase and shown that such GSH conjugates are excreted into the bile in healthy rats as well as rats dosed with lithocholic acid or ursodeoxycholic acid. To examine whether such novel BA-GSH conjugates are present in human bile, we determined the concentration of the GSH conjugates of the five BA that predominate in human bile. Bile was obtained from three infants (age 4, 10, and 13 months) and the BA-GSH conjugates quantified by means of liquid chromatography (LC)/electrospray ionization (ESI)-linear ion trap mass spectrometry (MS) in negative-ion scan mode, monitoring characteristic transitions of the analytes. By LC/ESI-MS, only primary BA were present in biliary BA, indicating that the dehydroxylating flora had not yet developed. GSH conjugates of chenodeoxycholic and lithocholic acid were present in concentrations ranging from 27 to 1120 pmol/ml, several orders of magnitude less than those of natural BA N-acylamidates. GSH conjugates were not present, however, in the ductal bile obtained from 10 adults (nine choledocholithiasis, one bile duct cancer). Our results indicate that BA-GSH conjugates are formed and excreted in human bile, at least in infants, although this novel mode of conjugation is a very minor pathway.

Laparoscopic common hepatic artery ligation and staging followed by distal pancreatectomy with en bloc resection of celiac artery for advanced pancreatic cancer

INTRODUCTION

Adeno-carcinomas of pancreatic body are usually asymptomatic and progress to advanced stage with involvement of major arteries. Resection of advanced cancer along with en bloc resection of a common hepatic artery and celiac trunk enables a "curative" resections and only possible treatment. However, the celiac axis resection always has a risk of compromising blood supply to liver, resulting in the hepatic insufficiency. We evaluated practicability of a two-stage procedure for the advanced pancreases body cancer, laparoscopic clamping of a common hepatic artery followed by open distal pancreatectomy with en bloc celiac arterial resection to prevent the hepatic insufficiency.

MATERIALS AND SURGICAL TECHNIQUE

Seventy-five-year-old woman diagnosed with a 50-mm pancreatic body mass, invading splenic artery, common hepatic artery, splenic vein, and portal vein at the confluence. STAGE-1: At laparoscopy, after confirming absence of the peritoneal, superficial liver metastases and negative peritoneal cytology; we approached the common hepatic artery through the lesser sac and ligated. STAGE-2: Her liver function tests were normal after 2 weeks, and CT angiography showed complete blockage of the common hepatic artery with sufficient collateral circulation to the liver through inferior pancreatico-duodenal artery and gastro-duodenal artery. We performed an open distal pancreatectomy with en bloc resection of celiac artery. Histopathology examination confirmed R0 resection.

DISCUSSION

The celiac axis resection with distal pancreatectomy improves the chance of R0 resection and potentially, survival of the patient. Preoperative laparoscopic ligation of the common hepatic artery is a safe, effective, and in-expensive technique to prevent postoperative hepatic insufficiency and improves the safety of en bloc celiac artery resection with a distal pancreatectomy. Also these patients have high risk of peritoneal dissemination. Diagnostic laparoscopy is useful to detect occult metastasis, which are missed by per-operative CT scan.

Genetic lineage tracing, a powerful tool to investigate the embryonic organogenesis and adult organ maintenance of the pancreas

Revealing the mechanism of adult organ maintenance and regeneration after injury is fundamental to our understanding of the pathogenesis of diseases. Considering the results of pulse and chase experiments using inducible insulin-Cre or Elastase-Cre, and more recently HNF1b-Cre, adult pancreatic cells (beta, acinar, and duct cells) seem to be maintained by the self-duplication of the existing cells, while there is still a dispute about whether adult beta-cells are supplied from the duct cells. Here we describe the advantages and pitfalls of Cre-mediated genetic lineage tracing experiments in the analysis of embryonic organogenesis and adult organ maintenance of the pancreas. This experimental technique enables us to visualize the specific cells and their progeny in vivo, and the combination of lineage tracing and other experimental procedures provides us with more detailed information on the mechanism of organogenesis and adult organ homeostasis.

Continuous cell supply from a Sox9-expressing progenitor zone in adult liver, exocrine pancreas and intestine

The liver and exocrine pancreas share a common structure, with functioning units (hepatic plates and pancreatic acini) connected to the ductal tree. Here we show that Sox9 is expressed throughout the biliary and pancreatic ductal epithelia, which are connected to the intestinal stem-cell zone. Cre-based lineage tracing showed that adult intestinal cells, hepatocytes and pancreatic acinar cells are supplied physiologically from Sox9-expressing progenitors. Combination of lineage analysis and hepatic injury experiments showed involvement of Sox9-positive precursors in liver regeneration. Embryonic pancreatic Sox9-expressing cells differentiate into all types of mature cells, but their capacity for endocrine differentiation diminishes shortly after birth, when endocrine cells detach from the epithelial lining of the ducts and form the islets of Langerhans. We observed a developmental switch in the hepatic progenitor cell type from Sox9-negative to Sox9-positive progenitors as the biliary tree develops. These results suggest interdependence between the structure and homeostasis of endodermal organs, with Sox9 expression being linked to progenitor status.

Optimal tissue tension for secure laparoscopic knots

Security and strength of a knot are main concerns of the surgeon since last 4000 years. The advancement of endoscopic and minimally invasive surgery in last few decades had a significant influence on a knot tying. The most difficult methods of a knot tying are performed during endoscopic procedures, in which the surgeon execute instrumentation from outside the body without palpation of organs and three-dimensional vision. In addition, laparoscopic instruments due to friction in transmission mechanism have very poor force feedback. This results into difficulty in applying the appropriate grasping force to the tissue, resulting in slippage or damage to the tissue. Our hypothesis highlights the need of tissue approximation at the 'optimum tissue tension' sufficient to resist the slippage of suture/clip without strangulation. The purpose of suture is to maintain an approximation of the tissue until healing progresses to the point where artificial support is no longer necessary for the wound to resist normal stress. When the approximation is too tight, tension in tissue leads to diminished blood supply resulting into the necrosis. Various tissues need different blood supply and different tissue pressure for optimum healings. Proposed hypothesis helps to improve the feedback of current knot pushers or clip applicators used in laparoscopic surgery using optimum tissue tension. Tissue approximation at an optimal tissue tension translates into the secure laparoscopic knot/clip application resulting in prevention of wound dehiscence, anastomosis leak, and secondary haemorrhages.

Diffusion-weighed MR imaging of pancreatic carcinoma

PURPOSE

The aim of this study was to demonstrate the feasibility of body diffusion-weighted (DW) MR imaging in the evaluation of a pancreatic carcinoma.

MATERIAL AND METHODS

In nine normal volunteers and in eight patients with pancreatic carcinoma, DW images were obtained on the axial plane scanning with a multisection spin-echo-type single-shot echo planar sequence with a body coil. Moreover, we measured the apparent diffusion coefficient (ADC) value in a circular region of interest (ROI) within the normal pancreas, pancreatic carcinoma, and tumor-associated chronic pancreatitis.

RESULTS

On the DW images, all eight carcinomas were clearly shown as high signal intensity relative to the surrounding tissue. The ADC value (x10(-3) mm(2)/s) in the carcinoma was 1.44 +/- 0.20, which was significantly lower compared to that of normal pancreas (1.90 +/- 0.06) and tumor-associated chronic pancreatitis (2.31 +/- 0.18).

CONCLUSION

Diffusion-weighted (DW) images can be helpful in detecting the pancreatic carcinoma and accessing the extent of the tumor.

Laparoscopic pancreatic resection: the past, present, and future

Since the early 1990s, laparoscopic techniques have been applied to a growing number of pancreatic surgeries. Laparoscopic pancreatic resections have been performed in patients with a variety of diseases including chronic pancreatitis, pancreatic trauma, congenital hyperinsulinism, and neoplasms of the pancreas; e.g., insulinoma, mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, etc. Laparoscopic pancreatic resections with an en bloc lymph node dissection have also been performed for invasive carcinomas. The long-term results after laparoscopic resections for invasive pancreatic cancer, however, are still not well defined. Laparoscopic distal pancreatectomies with or without spleen preservation may benefit patients with reduced postoperative pain, shorter hospital stay, a quicker recovery to normal activity, and better cosmetic appearances based on retrospective analyses of collective series and case reports. Prospective randomized controlled trials are needed to validate these benefits. In contrast, laparoscopic proximal pancreatectomies with or without duodenum preservation remain controversial. Although a laparoscopic pancreaticoduodenectomy and laparoscopic duodenum-preserving pancreatic head resection are technically feasible, laparoscopic reconstruction after proximal pancreatectomies is not yet generally practicable but limited to personal experiences by highly skilled endoscopic surgeons. To justify the performance of laparoscopic proximal pancreatectomies, it is mandatory to demonstrate the potential clinical benefits and safety of these complicated procedures.

Clinical importance of precursor lesions in the pancreas

Three distinct noninvasive precursor lesions to invasive ductal adenocarcinoma of the pancreas have been described. These include the mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, and pancreatic intraepithelial neoplasia. The early detection and treatment of these lesions can interrupt the progression of a curable noninvasive precursor to an almost uniformly deadly invasive cancer.

Current understanding of precursors to pancreatic cancer

Precursors to pancreatic cancer have been investigated for a century. Previous studies have revealed three distinct precursors, i.e. mucinous cystic neoplasm (MCN), intraductal papillary mucinous neoplasm (IPMN), and pancreatic intraepithelial neoplasia (PanIN), harboring identical or similar genetic alterations as does invasive pancreatic carcinoma. The current understanding of precursors to pancreatic cancer can be illustrated by progressive pathways from noninvasive MCN, IPMN, and PanIN toward invasive carcinoma. MCNs consist of ovarian-type stroma and epithelial lining with varying grades of atypia, and are occasionally associated with invasive adenocarcinoma. The epithelium of noninvasive IPMNs shows a variety of different directions of differentiation, including gastric, intestinal, pancreatobiliary (PB), and oncocytic types. IPMNs can also harbor varying grades of architectural and cytologic atypia. IPMNs confined to branch ducts are mostly the gastric type, and IPMNs involving the main ducts are often intestinal type, while PB and oncocytic types are rare. Small (<1 cm) IPMNs of the gastric type are not always morphologically distinguishable from low-grade PanINs. Mucin expression profiles suggest intestinal-type IPMNs progress to mucinous noncystic (colloid) carcinoma, while PB-type IPMNs progress toward ductal adenocarcinoma. It is a well-described paradigm that PanIN lesions progress toward ductal adenocarcinoma through step-wise genetic alterations. The activation of Hedgehog and Notch signaling pathways in PanIN lesions as well as in pancreatic adenocarcinoma suggest that developmental pathways may be disregulated during carcinogenesis of the pancreas. Further study is needed to elucidate the pathways from precursors toward invasive carcinoma of the pancreas.

Current topics on precursors to pancreatic cancer

Prognosis of invasive pancreatic ductal adenocarcinoma is bleak and the vast majority of patients with pancreatic cancer die of their disease. The detection and treatment of the non-invasive precursor lesions of pancreatic cancer offer the opportunity to cure this devastating disease and therefore great efforts are being made to identify the precursors to pancreatic cancer. Several distinct precursor lesions have been identified. Mucinous cystic neoplasms (MCNs), intraductal papillary mucinous neoplasms (IPMNs), and pancreatic intraepithelial neoplasias (PanINs) all harbor varying degrees of dysplasia and stepwise accumulation of genetic alterations, suggesting progression of these lesions from benign toward malignant neoplasms. MCNs have a characteristic ovarian-type stroma. About one-third of MCNs are associated with invasive carcinoma of ductal phenotype. IPMNs are recently established clinical entity with characteristic features of mucin hypersecretion and duct dilatation. Some IPMNs are associated with invasive carcinoma and IPMNs are recognized precursors to pancreatic cancer. PanINs are microscopic proliferative lesions arising from any parts of the pancreatic duct system. Low grade PanINs are commonly found in pancreatic ducts of elder individuals, while high grade PanINs, previously called carcinoma in situ/severe ductal dysplasia, may eventually give rise to invasive pancreatic cancer. Appropriate clinical managements are requisite for patients with MCNs, IPMNs and PanINs. Further investigation of these precursor lesions is expected to reduce the mortality from pancreatic cancer.

Classification of types of intraductal papillary-mucinous neoplasm of the pancreas: a consensus study

Now that more than two decades have passed since the first reports of intraductal papillary-mucinous neoplasms (IPMNs), it has become clear that IPMN consists of a spectrum of neoplasms with both morphological and immunohistochemical variations. At a meeting of international experts on pancreatic precursor lesions held in 2003, it was agreed that a consensus classification of IPMN subtypes should be established to enable a more detailed analysis of the clinicopathological significance of the variations. Based on our experience and on information from the literature, we selected representative histological examples of IPMNs and defined a consensus nomenclature and criteria for classifying variants as distinctive IPMN subtypes including gastric type, intestinal type, pancreatobiliary type, and oncocytic type. These definitions can be used for further analyses of the clinicopathological significance of the variations of IPMN.

Concomitant overexpression of cyclooxygenase-2 in HER-2-positive on Smad4-reduced human gastric carcinomas is associated with a poor patient outcome

PURPOSE

The expression of cyclooxygenase-2 (COX-2) is known to be involved in gastric carcinogenesis and tumor progression, but little is known about the mechanisms responsible for the up-regulation of COX-2. We examined the involvement of two growth factor-signaling systems, HER-2 and transforming growth factor (TGF)-beta, in the induction of COX-2 in human gastric cancer tissue.

EXPERIMENTAL DESIGN

COX-2 expression was detected by immunohistochemistry in surgical specimens obtained from 166 patients with advanced gastric cancer; possible correlations between the expression of COX-2 and the expression of HER-2, TGF-beta1, and Smad4, an intracellular mediator that transmits the TGF-beta signal, were then analyzed.

RESULTS

COX-2 protein was overexpressed in 91 (54.8%) tumors; COX-2 overexpression was correlated with a differentiated histologic type, deep invasion, and positive lymph node metastasis. COX-2 was frequently overexpressed in HER-2-positive tumors (19 of 22, 86.4%) and in Smad4-reduced tumors (67 of 104, 64.4%) but irrelevant to the TGF-beta1 expression status. The expression levels of COX-2 and HER-2 and the reduction in Smad4 were all associated with a poor patient outcome. A multivariate analysis demonstrated a significantly poor outcome for the concomitant overexpression of COX-2 in patients with Smad4-reduced tumors.

CONCLUSIONS

These results support the possibility that signal transduction via HER-2 and the TGF-beta/Smad system may be implicated in COX-2 expression and that the reduction of Smad4 may be, in part, of causal significance in the TGF-beta-initiated overexpression of COX-2, which is associated with a poor prognosis for patients with gastric cancer.

Precursors to invasive pancreatic cancer

Pancreatic cancer, once invasive, is almost uniformly fatal. In order to alleviate the dismal prognosis associated with this disease, it is imperative that pancreatic cancer be recognized and treated prior to invasion. Understanding the morphology and biology of precursor lesions of invasive pancreatic cancer has therefore become an issue of paramount importance. In the last decade, significant progress has been in the recognition and appropriate classification of these precursor lesions, and the current review will focus on our state-of-the-art knowledge on this topic. Mucinous cystic neoplasms (MCNs), intraductal papillary mucinous neoplasms (IPMNs), and pancreatic intraepithelial neoplasia (PanIN) encompass the three known morphologically distinct precursors to invasive pancreatic cancer. In addition to discussion of the "classic" precursor entities, this review will also address some of the recent diagnostic controversies for these lesions, in particular features that distinguish IPMNs from PanIN lesions. Finally, the potential clinical impact of recognizing these precursor lesions in the context of early detection of pancreatic cancer will be discussed.

A secure technique of intracorporeal Roux-Y reconstruction after laparoscopic distal gastrectomy

BACKGROUND

Laparoscopic distal gastrectomy [LDG] is a minimally invasive surgery for gastric carcinoma. The Billroth I method has been commonly employed to reconstruct alimentary tract after LDG. Conversely, Roux-Y reconstruction is employed far less commonly despite its merits. Technical difficulties, including a risk of twisting the Roux loop under limited vision through a laparoscope, have hampered Roux-Y reconstruction after LDG.

METHODS

We performed LDG and intracorporeal Roux-Y reconstruction in 5 patients with early gastric cancer. The procedure included a functional end-to-end anastmosis of the stomach and jejunum, consisting of side-to-side approximation of jejunal loop to greater curvature of the gastric remnant with a laparoscopic stapling device followed by closure of the open end and simultaneous division of the jejunum with another stapler.

RESULTS

Roux-Y reconstruction was successfully accomplished without torsion of the loop in all patients.

CONCLUSIONS

By using the present technique, intracorporeal Roux-Y reconstruction after LDG can be accomplished without a risk of twisting the jejunal loop.

Protein-bound polysaccharide isolated from basidiomycetes inhibits endotoxin-induced activation by blocking lipopolysaccharide-binding protein and CD14 functions

The protein-bound polysaccharide isolated from basidiomycetes (PSK) is a biological response modifier capable of exhibiting various biological activities, such as antitumor and antimicrobial effects. In the present study, we found that PSK suppressed interleukin (IL)-6 production in murine peritoneal macrophages stimulated with endotoxic lipopolysaccharide (LPS) and its synthetic lipid A (compound 506). Nitric oxide production and p38 mitogen-associated protein kinase phosphorylation induced in a murine macrophage cell line, J774-A1, by LPS and compound 506 were also inhibited by PSK. Further, PSK distinctly suppressed nuclear factor-kappaB activation in Ba/F3 cells expressing mouse Toll-like receptor 4 and MD-2, following stimulation with LPS and compound 506, however, not with Taxol. These PSK-induced inhibitory activities were caused by inhibition of the physical associations of LPS with LPS-binding protein (LBP) and CD14. PSK also protected mice from LPS-induced lethality, presumably by down-regulating IL-6 and tumor necrosis factor-alpha concentrations in serum. These findings indicate that PSK, which also has an ability to regulate LBP/CD14 functions, may be useful for clinical control of endotoxic sepsis.

Correlations of hemoglobin index (IHb) of gastric mucosa with Helicobacter pylori (H. pylori) infection and inflammation of gastric mucosa

BACKGROUND

Helicobacter pylori (H. pylori) infection causes various gastric diseases, among them H. pylori-associated gastritis characterized by diffuse redness of the gastric mucosa. The haemoglobin index (IHb) of the fundic mucosa is an objective parameter of the extent of mucosal redness, but it is unclear whether or not IHb can be used as a diagnostic marker for H. pylori infection. The purpose of this investigation was to evaluate the correlations between IHb of the fundic mucosa and H. pylori infection, inflammatory cell infiltration, and inflammatory mediator production.

METHODS

IHb of the fundic mucosa was measured in 108 patients with various gastric diseases (group 1), and values were compared between H. pylori-positive and H. pylori-negative patients. Fifteen patients with H. pylori infection from group 1 underwent H. pylori eradication therapy and IHb was measured before and after treatment. Both IHb and inflammatory cell infiltration were assessed in 61 patients (group 2). In 31 patients from group 2, the expression of interleukin (IL)-8 and inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) was assayed in gastric biopsy specimens by the reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

IHb levels were significantly higher in H. pylori-positive patients than in H. pylori-negative patients (P < 0.001). IHb was decreased at one month after the eradication of H. pylori (P < 0.001). IHb was higher in patients with infiltration by both mononuclear cells and neutrophils (P < 0.001). There was a significant correlation between the IHb level and the expression of IL-8 mRNA (P < 0.001), as well as between IHb and iNOS mRNA expression (P < 0.05).

CONCLUSIONS

There were significant correlations between IHb of the gastric mucosa and H. pylori infection, inflammatory cell infiltration, and IL-8/iNOS mRNA expression, suggesting that IHb is a reliable marker of H. pylori infection for use during follow-up endoscopy after H. pylori eradication therapy.

An illustrated consensus on the classification of pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasms

Invasive pancreatic ductal adenocarcinoma is an almost uniformly fatal disease. Several distinct noninvasive precursor lesions can give rise to invasive adenocarcinoma of the pancreas, and the prevention, detection, and treatment of these noninvasive lesions offers the potential to cure early pancreatic cancers. Noninvasive precursors of invasive ductal adenocarcinoma of the pancreas include pancreatic intraepithelial neoplasias (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms. Diagnostic criteria, including a distinct ovarian-type stroma, and a consistent nomenclature are well established for mucinous cystic neoplasms. By contrast, consistent nomenclatures and diagnostic criteria have been more difficult to establish for PanINs and IPMNs. Because both PanINs and IPMNs consist of intraductal neoplastic proliferations of columnar, mucin-containing cells with a variable degree of papilla formation, the distinction between these two classes of precursor lesions remains problematic. Thus, considerable ambiguities still exist in the classification of noninvasive neoplasms in the pancreatic ducts. A meeting of international experts on precursor lesions of pancreatic cancer was held at The Johns Hopkins Hospital from August 18 to 19, 2003. The purpose of this meeting was to define an international acceptable set of diagnostic criteria for PanINs and IPMNs and to address a number of ambiguities that exist in the previously reported classification systems for these neoplasms. We present a consensus classification of the precursor lesions in the pancreatic ducts, PanINs and IPMNs.

Pancreatic intraepithelial neoplasia

Great efforts have been devoted to detecting preinvasive precursors to ductal carcinoma of the pancreas in the hope of improving the currently bleak prognosis of invasive pancreatic cancer. Intensive investigations of the pancreas have led to the recognition of intraductal papillary mucinous neoplasms (IPMNs) and the detection of preinvasive precursors to conventional ductal carcinoma. The pancreatic intraepithelial neoplasia (PanIN) nomenclature for precursor lesions of ductal carcinoma was developed at the "Pancreatic Cancer Think Tank" held in the United States in 1999. However, some reports of precursor lesions have suggested that these definitions do not encompass the full spectrum of precursors of ductal carcinoma, and these issues were the subject of the "Forum on Carcinoma In Situ of the Pancreas" held in Japan in 2002. After this forum, it became clear that the existing definitions of PanINs needed to be revised and expanded. Both participants of the Pancreatic Cancer Think Tank and the Forum gathered together at a meeting on precursor lesions of pancreatic cancer in 2003, and an international consensus on the diagnostic criteria for PanINs and IPMNs was created. We describe herein the current understanding of precursor lesions of pancreatic cancer.

Clinicopathological features of pancreatic intraepithelial neoplasias and their relationship to intraductal papillary-mucinous tumors

Pancreatic intraepithelial neoplasia (PanIN) is a recently proposed nomenclature for putative precursor lesions of pancreatic cancer, which are designated as PanIN-1 through -3 according to their increasing grade of dysplasia. A stepwise progression model of PanINs has been proposed, and multistep genetic alterations in PanINs are being investigated. PanIN-1A and PanIN-1B may remain unchanged for a long period. PanIN-3 potentially progresses toward invasive ductal carcinoma (IDC), and there are several case reports suggesting such progression. In these reported patients, PanIN-3 was found in specimens from partial pancreatectomies, and IDC manifested in the pancreatic remnant 17 months to 29 years after the surgery. We describe herein a patient with PanIN-3, in whom IDC manifested in the distal remnant pancreas 69 months after segmental pancreatectomy. Of the reported cases, including the present one, four of the patients were male and three were female, and the age at the first operation ranged from 46 to 70 years. Intraductal papillary-mucinous tumor (IPMT) is an entity that is distinct from PanIN. However, IPMTs of small size resemble PanINs morphologically. Loss of Dpc4 expression has been reported in the invasive component of IPMT, as well as in PanIN-3 and IDC. Analysis of mucin expression patterns has been reported, suggesting that, in practice, MUC1-positive MUC2-negative IPMTs may not be distinguishable from PanINs. There may be overlapping lesions between PanINs and IPMTs. Should the paradigm of the ductal origin of IDC be accepted, PanINs and a fraction of IPMTs would represent precursors of IDC.