Endoscopic papillectomy for ampullary lesions of minor papilla

BACKGROUND AND AIMS

Ampullary lesions (ALs) of the minor duodenal papilla are extremely rare. Endoscopic papillectomy (EP) is a routinely used treatment for AL of the major duodenal papilla, but the role of EP for minor AL has not been accurately studied.

METHODS

We identified 20 patients with ALs of minor duodenal papilla in the multicentric database from the Endoscopic Papillectomy vs Surgical Ampullectomy vs Pancreatitcoduodenectomy for Ampullary Neoplasm study, which included 1422 EPs. We used propensity score matching (nearest-neighbor method) to match these cases with ALs of the major duodenal papilla based on age, sex, histologic subtype, and size of the lesion in a 1:2 ratio. Cohorts were compared by means of chi-square or Fisher exact test as well as Mann-Whitney U test.

RESULTS

Propensity score-based matching identified a cohort of 60 (minor papilla 20, major papilla 40) patients with similar baseline characteristics. The most common histologic subtype of lesions of minor papilla was an ampullary adenoma in 12 patients (3 low-grade dysplasia and 9 high-grade dysplasia). Five patients revealed nonneoplastic lesions. Invasive cancer (T1a), adenomyoma, and neuroendocrine neoplasia were each found in 1 case. The rate of complete resection, en-bloc resection, and recurrences were similar between the groups. There were no severe adverse events after EP of lesions of minor papilla. One patient had delayed bleeding that could be treated by endoscopic hemostasis, and 2 patients showed a recurrence in surveillance endoscopy after a median follow-up of 21 months (interquartile range, 12-50 months).

CONCLUSIONS

EP is safe and effective in ALs of the minor duodenal papilla. Such lesions could be managed according to guidelines for EP of major duodenal papilla.

Endoscopic papillectomy for ampullary lesions in patients with familial adenomatous polyposis compared with sporadic lesions: a propensity score-matched cohort

BACKGROUND

Familial adenomatous polyposis (FAP) is a rare inherited syndrome that predisposes the patient to cancer. Treatment of FAP-related ampullary lesions is challenging and the role of endoscopic papillectomy has not been elucidated. We retrospectively analyzed the outcomes of endoscopic papillectomy in matched cohorts of FAP-related and sporadic ampullary lesions (SALs).

METHODS

This retrospective multicenter study included 1422 endoscopic papillectomy procedures. Propensity score matching including age, sex, comorbidity, histologic subtype, and size was performed. Main outcomes were complete resection (R0), technical success, complications, and recurrence.

RESULTS

Propensity score matching identified 202 patients (101 FAP, 101 SAL) with comparable baseline characteristics. FAP patients were mainly asymptomatic (79.2 % [95 %CI 71.2-87.3] vs. 46.5 % [95 %CI 36.6-56.4]); P < 0.001). The initial R0 rate was significantly lower in FAP patients (63.4 % [95 %CI 53.8-72.9] vs. 83.2 % [95 %CI 75.8-90.6]; P = 0.001). After repeated interventions (mean 1.30 per patient), R0 was comparable (FAP 93.1 % [95 %CI 88.0-98.1] vs. SAL 97.0 % [95 %CI 93.7-100]; P = 0.19). Adverse events occurred in 28.7 %. Pancreatitis and bleeding were the most common adverse events in both groups. Severe adverse events were rare (3.5 %). Overall, 21 FAP patients (20.8 % [95 %CI 12.7-28.8]) and 16 SAL patients (15.8 % [95 %CI 8.6-23.1]; P = 0.36) had recurrence. Recurrences occurred later in FAP patients (25 [95 %CI 18.3-31.7] vs. 2 [95 %CI CI 0.06-3.9] months).

CONCLUSIONS

Endoscopic papillectomy was safe and effective in FAP-related ampullary lesions. Criteria for endoscopic resection of ampullary lesions can be extended to FAP patients. FAP patients have a lifetime risk of relapse even after complete resection, and require long-time surveillance.

Endoscopic and Surgical Management of Non-Metastatic Ampullary Neuroendocrine Neoplasia: A Multi-Institutional Pancreas2000/EPC Study

INTRODUCTION

Ampullary neuroendocrine neoplasia (NEN) is rare and evidence regarding their management is scarce. This study aimed to describe clinicopathological features, management, and prognosis of ampullary NEN according to their endoscopic or surgical management.

METHODS

From a multi-institutional international database, patients treated with either endoscopic papillectomy (EP), transduodenal surgical ampullectomy (TSA), or pancreaticoduodenectomy (PD) for ampullary NEN were included. Clinical features, post-procedure complications, and recurrences were assessed.

RESULTS

65 patients were included, 20 (30.8%) treated with EP, 19 (29.2%) with TSA, and 26 (40%) with PD. Patients were mostly asymptomatic (n = 46; 70.8%). Median tumor size was 17 mm (12-22), tumors were mostly grade 1 (70.8%) and pT2 (55.4%). Two (10%) EP resulted in severe American Society for Gastrointestinal Enterology (ASGE) adverse post-procedure complications and 10 (50%) were R0. Clavien 3-5 complications did not occur after TSA and in 4, including 1 postoperative death (15.4%) of patients after PD, with 17 (89.5%) and 26 R0 resection (100%), respectively. The pN1/2 rate was 51.9% (n = 14) after PD. Tumor size larger than 1 cm (i.e., pT stage >1) was a predictor for R1 resection (p < 0.001). Three-year overall survival and disease-free survival after EP, TSA, and PD were 92%, 68%, 92% and 92%, 85%, 73%, respectively.

CONCLUSION

Management of ampullary NEN is challenging. EP should not be performed in lesions larger than 1 cm or with a endoscopic ultrasonography T stage beyond T1. Local resection by TSA seems safe and feasible for lesions without nodal involvement. PD should be preferred for larger ampullary NEN at risk of nodal metastasis.

Outcomes of rescue procedures in the management of locally recurrent ampullary tumors: A Pancreas 2000/EPC study

BACKGROUND

Ampullary lesions are rare and can be locally treated either with endoscopic papillectomy or transduodenal surgical ampullectomy. Management of local recurrence after a first-line treatment has been poorly studied.

METHODS

Patients with a local recurrence of an ampullary lesion initially treated with endoscopic papillectomy or transduodenal surgical ampullectomy were retrospectively included from a multi-institutional database (58 centers) between 2005 and 2018.

RESULTS

A total of 103 patients were included, 21 (20.4%) treated with redo endoscopic papillectomy, 14 (13.6%) with transduodenal surgical ampullectomy, and 68 (66%) with pancreaticoduodenectomy. Redo endoscopic papillectomy had low morbidity with 4.8% (n = 1) severe to fatal complications and a R0 rate of 81% (n = 17). Transduodenal surgical ampullectomy and pancreaticoduodenectomy after a first procedure had a higher morbidity with Clavien III and more complications, respectively, 28.6% (n = 4) and 25% (n = 17); R0 resection rates were 85.7% (n = 12) and 92.6% (n = 63), both without statistically significant difference compared to endoscopic papillectomy (P = .1 and 0.2). Pancreaticoduodenectomy had 4.4% (n = 2) mortality. No deaths were registered after transduodenal surgical ampullectomy or endoscopic papillectomy. Recurrences treated with pancreaticoduodenectomy were more likely to be adenocarcinomas (79.4%, n = 54 vs 21.4%, n = 3 for transduodenal surgical ampullectomy and 4.8%, n = 1 for endoscopic papillectomy, P < .0001). Three-year overall survival and disease-free survival were comparable.

CONCLUSION

Endoscopy is appropriate for noninvasive recurrences, with resection rate and survival outcomes comparable to surgery. Surgery applies more to invasive recurrences, with transduodenal surgical ampullectomy rather for carcinoma in situ and early cancers and pancreaticoduodenectomy for more advanced tumors.

Systematic Review with Meta-Analysis: Endoscopic and Surgical Resection for Ampullary Lesions

Ampullary lesions (ALs) can be treated by endoscopic (EA) or surgical ampullectomy (SA) or pancreaticoduodenectomy (PD). However, EA carries significant risk of incomplete resection while surgical interventions can lead to substantial morbidity. We performed a systematic review and meta-analysis for R0, adverse-events (AEs) and recurrence between EA, SA and PD. Electronic databases were searched from 1990 to 2018. Outcomes were calculated as pooled means using fixed and random-effects models and the Freeman-Tukey-Double-Arcsine-Proportion-model. We identified 59 independent studies. The pooled R0 rate was 76.6% (71.8–81.4%, I² = 91.38%) for EA, 96.4% (93.6–99.2%, I² = 37.8%) for SA and 98.9% (98.0–99.7%, I² = 0%) for PD. AEs were 24.7% (19.8–29.6%, I² = 86.4%), 28.3% (19.0–37.7%, I² = 76.8%) and 44.7% (37.9–51.4%, I² = 0%), respectively. Recurrences were registered in 13.0% (10.2–15.6%, I² = 91.3%), 9.4% (4.8–14%, I² = 57.3%) and 14.2% (9.5–18.9%, I² = 0%). Differences between proportions were significant in R0 for EA compared to SA (p = 0.007) and PD (p = 0.022). AEs were statistically different only between EA and PD (p = 0.049) and recurrence showed no significance for EA/SA or EA/PD. Our data indicate an increased rate of complete resection in surgical interventions accompanied with a higher risk of complications. However, studies showed various sources of bias, limited quality of data and a significant heterogeneity, particularly in EA studies.

Surgical intervention for intestinal typhoid perforation

AIM

Typhoid perforation is the most fatal complication of typhoid fever in developing countries and is most often caused by the bacteria Salmonella Typhi. There are conflicting views as to which type of surgical intervention gives the best outcome. The aim of this study was to determine the mortality associated with the different types of surgical interventions employed in patients with typhoid perforation.

METHOD

This was a retrospective review of the medical records of adult and paediatric surgical patients treated in the general and paediatric surgical units of the Korle Bu Teaching Hospital. Information was obtained from medical records at the Korle Bu Teaching Hospital in Accra, Ghana, between January 2009 and April 2012. The data was analysed using IBM SPSS Statistics version 20 and 22.

RESULTS

133 patients (median age of 21 years, 72.2% males) with typhoid perforation were included in the study. The typhoid perforation specific mortality rate was 12.8%. Males had a significantly lower mortality rate (7.3%) compared to females (27%). Simple bowel closure (85.7% of total) was the most common surgical intervention performed and patients operated upon with this method had a significantly lower mortality rate (9.6%) compared to patients with bowel resection (31.6%).

CONCLUSIONS

In this study, patients treated with intestinal resection were more likely to die from typhoid perforation and female gender was a risk factor for death. Simple bowel closure was the predominant surgical procedure.

Platelet-derived CXCL4 regulates neutrophil infiltration and tissue damage in severe acute pancreatitis

Platelets are known to play an important role in acute pancreatitis (AP) via promotion of neutrophil accumulation, although mechanisms behind platelet-dependent accumulation of neutrophils in the pancreas remain elusive. Platelets contain a wide spectrum of different pro-inflammatory compounds, such as chemokines. CXCL4 (platelet factor 4) is one of the most abundant chemokine in platelets, and we hypothesized that CXCL4 might be involved in platelet-dependent accumulation of neutrophils in the inflamed pancreas. The aim of this study was to examine the role of CXCL4 in severe AP. Pancreatitis was provoked by infusion of taurocholate into the pancreatic duct or by intraperitoneal administration of L-arginine in C57BL/6 mice. Animals were treated with an antibody against platelets or CXCL4 before induction of pancreatitis. Plasma and lung levels of CXCL2, CXCL4, and interleukin (IL)-6 were determined by use of enzyme-linked immunosorbent assay. Flow cytometry was used to examine surface expression of macrophage-1 (Mac-1) on neutrophils. Plasma was obtained from healthy individuals (controls) and patients with AP. Challenge with taurocholate increased plasma levels of CXCL4, and depletion of platelets markedly reduced plasma levels of CXCL4 indicating that circulating levels of CXCL4 are mainly derived from platelets in AP. Inhibition of CXCL4 reduced taurocholate-induced neutrophil recruitment, IL-6 secretion, edema formation, amylase release, and tissue damage in the pancreas. However, immunoneutralization of CXCL4 had no effect on CXCL2-evoked neutrophil expression of Mac-1 or chemotaxis in vitro, suggesting an indirect effect of CXCL4 on neutrophil recruitment in AP. Targeting CXCL4 significantly attenuated plasma and lung levels of CXCL2, which is a potent neutrophil chemoattractant, and inhibition of the CXCL2 receptor attenuated neutrophil infiltration and tissue damage in the inflamed pancreas. A significant role of CXCL4 was confirmed in an alternate model of AP induced by L-arginine challenge. Moreover, patients with AP had significantly increased plasma levels of CXCL4 compared with healthy controls. These findings' results suggest that platelet-derived CXCL4 is a potent stimulator of neutrophil accumulation in AP and that this is mediated via generation of CXCL2 in the inflamed pancreas. We conclude that CXCL4 plays an important role in pancreatic inflammation and that targeting CXCL4 might be a useful way to ameliorate tissue damage in AP.

Neutrophil Extracellular Traps Induce Trypsin Activation, Inflammation, and Tissue Damage in Mice With Severe Acute Pancreatitis

BACKGROUND & AIMS

Neutrophils are involved in the development of acute pancreatitis (AP), but it is not clear how neutrophil-induced tissue damage is regulated. In addition to secreting antimicrobial compounds, activated neutrophils eliminate invading microorganisms by expelling nuclear DNA and histones to form extracellular web-like structures called neutrophil extracellular traps (NETs). However, NETs have been reported to contribute to organ dysfunction in patients with infectious diseases. We investigated whether NETs contribute to the development of AP in mice.

METHODS

AP was induced in C57BL/6 mice by infusion of taurocholate into the pancreatic duct or by intraperitoneal administration of L-arginine. Pancreata were collected and extracellular DNA was detected by Sytox green staining, levels of CXC chemokines, histones, and cytokines also were measured. Cell-free DNA was quantified in plasma samples. Signal transducer and activator of transcription 3 phosphorylation and trypsin activation were analyzed in isolated acinar cells. NETs were depleted by administration of DNase I to mice. Plasma was obtained from healthy individuals (controls) and patients with severe AP.

RESULTS

Infusion of taurocholate induced formation of NETs in pancreatic tissues of mice and increased levels of cell-free DNA in plasma. Neutrophil depletion prevented taurocholate-induced deposition of NETs in the pancreas. Administration of DNase I to mice reduced neutrophil infiltration and tissue damage in the inflamed pancreas and lung, and decreased levels of blood amylase, macrophage inflammatory protein-2, interleukin 6, and high-mobility groups protein 1. In mice given taurocholate, DNase I administration also reduced expression of integrin α M (macrophage-1 antigen) on circulating neutrophils. Similar results occurred in mice with L-arginine-induced AP. Addition of NETs and histones to acinar cells induced formation of trypsin and activation of signal transducer and activator of transcription 3; these processes were blocked by polysialic acid. Patients with severe AP had increased plasma levels of NET components compared with controls.

CONCLUSIONS

NETs form in the pancreata of mice during the development of AP, and NET levels are increased in plasma from patients with AP, compared with controls. NETs regulate organ inflammation and injury in mice with AP, and might be targeted to reduce pancreatic tissue damage and inflammation in patients.

Human thrombin-derived host defense peptides inhibit neutrophil recruitment and tissue injury in severe acute pancreatitis

Severe acute pancreatitis (AP) is characterized by leukocyte infiltration and tissue injury. Herein, we wanted to examine the potential effects of thrombin-derived host defense peptides (TDPs) in severe AP. Pancreatitis was provoked by infusion of taurocholate into the pancreatic duct or by intraperitoneal administration of l-arginine in C57BL/6 mice. Animals were treated with the TDPs GKY20 and GKY25 or a control peptide WFF25 30 min before induction of AP. TDPs reduced blood amylase levels, neutrophil infiltration, hemorrhage, necrosis, and edema formation in the inflamed pancreas. Treatment with TDPs markedly attenuated the taurocholate-induced increase in plasma levels of CXCL2 and interleukin-6. Moreover, administration of TDPs decreased histone 3, histone 4, and myeloperoxidase levels in the pancreas in response to taurocholate challenge. Interestingly, administration of TDPs abolished neutrophil expression of Mac-1 in mice with pancreatitis. In addition, TDPs inhibited CXCL2-induced chemotaxis of isolated neutrophils in vitro. Fluorescent-labeled TDP was found to directly bind to isolated neutrophils. Finally, a beneficial effect of TDPs was confirmed in l-arginine-induced pancreatitis. Our novel results demonstrate that TDPs exert protective effects against pathological inflammation and tissue damage in AP. These findings suggest that TDPs might be useful in the management of patients with severe AP.

Inhibition of geranylgeranyltransferase attenuates neutrophil accumulation and tissue injury in severe acute pancreatitis

Leukocyte infiltration and acinar cell necrosis are hallmarks of severe AP, but the signaling pathways regulating inflammation and organ injury in the pancreas remain elusive. In the present study, we investigated the role of geranylgeranyltransferase in AP. Male C57BL/6 mice were treated with a geranylgeranyltransferase inhibitor GGTI-2133 (20 mg/kg) prior to induction of pancreatitis by infusion of taurocholate into the pancreatic duct. Pretreatment with GGTI-2133 reduced plasma amylase levels, pancreatic neutrophil recruitment, hemorrhage, and edema formation in taurocholate-evoked pancreatitis. Moreover, administration of GGTI-2133 decreased the taurocholate-induced increase of MPO activity in the pancreas and lung. Treatment with GGTI-2133 markedly reduced levels of CXCL2 in the pancreas and IL-6 in the plasma in response to taurocholate challenge. Notably, geranylgeranyltransferase inhibition abolished neutrophil expression of Mac-1 in mice with pancreatitis. Finally, inhibition of geranylgeranyltransferase had no direct effect on secretagogue-induced activation of trypsinogen in pancreatic acinar cells in vitro. A significant role of geranylgeranyltransferase was confirmed in an alternate model of AP induced by L-arginine challenge. Our findings show that geranylgeranyltransferase regulates neutrophil accumulation and tissue damage via expression of Mac-1 on neutrophils and CXCL2 formation in AP. Thus, these results reveal new signaling mechanisms in pancreatitis and indicate that targeting geranylgeranyltransferase might be an effective way to ameliorate severe AP.

Fruit and vegetable intake and the risk of gastric adenocarcinoma: a reanalysis of the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST) study after a longer follow-up

In a previous European prospective investigation into cancer and nutrition (EPIC) analysis, we found an inverse association between total intake of vegetables, onion and garlic, and risk of intestinal gastric cancer (GC) and between citrus fruit and risk of cardia GC. The aim of this study is to reanalyze the effect of fruit and vegetables (F&V), based on a longer follow-up and twice the number of GC cases. Subjects are 477,312 men and women mostly aged 35 to 70 years participating in the EPIC cohort, including 683 gastric adenocarcinomas with 11 years of follow-up. Information on diet and lifestyle was collected at baseline. A calibration study in a subsample was used to correct for dietary measurement errors. When comparing the highest vs. lowest quintile of intake, we found an inverse association between total intake of V&F and GC risk [hazard ratio (HR) 0.77; 95% confidence interval (CI) 0.57-1.04; p for trend 0.02], between fresh fruit and risk of the diffuse type (HR 0.59; 95% CI 0.36-0.97; p for trend 0.03) and an inverse association between citrus fruit and risk of cardia cancer (HR 0.61; 95% CI 0.38-1.00, p for trend 0.01). Although calibration revealed somewhat stronger inverse associations, none of the risks reached statistical significance. There was no association between total or specific vegetables intake and GC risk. The inverse association between fresh fruit and citrus fruits and risk of GC seems to be restricted to smokers and the Northern European countries. Fresh fruit and citrus fruit consumption may protect against diffuse and cardia GC, respectively.

The associations of advanced glycation end products and its soluble receptor with pancreatic cancer risk: a case-control study within the prospective EPIC Cohort

BACKGROUND

Advanced glycation end products (AGE) and their receptors (RAGE) have been implicated in cancer development through their proinflammatory capabilities. However, prospective data on their association with cancer of specific sites, including pancreatic cancer, are limited.

METHODS

Prediagnostic blood levels of the AGE product Nε-(carboxymethyl)lysine (CML) and the endogenous secreted receptor for AGE (esRAGE) were measured using ELISA in 454 patients with exocrine pancreatic cancer and individually matched controls within the European Prospective Investigation into Cancer and Nutrition (EPIC). Pancreatic cancer risk was estimated by calculating ORs with corresponding 95% confidence intervals (CI).

RESULTS

Elevated CML levels tended to be associated with a reduction in pancreatic cancer risk [OR = 0.57 (95% CI, 0.32-1.01) comparing highest with lowest quintile), whereas no association was observed for esRAGE (OR = 0.98; 95% CI, 0.62-1.54). Adjustments for body mass index and smoking attenuated the inverse associations of CML with pancreatic cancer risk (OR = 0.78; 95% CI, 0.41-1.49). There was an inverse association between esRAGE and risk of pancreatic cancer for cases that were diagnosed within the first 2 years of follow-up [OR = 0.46 (95% CI, 0.22-0.96) for a doubling in concentration], whereas there was no association among those with a longer follow-up (OR = 1.11; 95% CI, 0.88-1.39; P(interaction) = 0.002).

CONCLUSIONS AND IMPACT

Our results do not provide evidence for an association of higher CML or lower esRAGE levels with risk of pancreatic cancer. The role of AGE/RAGE in pancreatic cancer would benefit from further investigations.

Early intraperitoneal metabolic changes and protease activation as indicators of pancreatic fistula after pancreaticoduodenectomy

BACKGROUND

Ischaemia and local protease activation close to the pancreaticojejunal anastomosis (PJA) are potential mechanisms of postoperative pancreatic fistula (POPF) formation. To provide information on the pathophysiology of POPF, intraperitoneal microdialysis was used to monitor metabolic changes and protease activation close to the PJA after pancreaticoduodenectomy (PD).

METHODS

In patients who underwent PD, intraperitoneal metabolites (glycerol, lactate, pyruvate and glucose) were measured by microdialysis, and lactate and glucose in blood were monitored, every 4 h for 5 days, starting at 12.00 hours on the day after surgery. Trypsinogen activation peptide (TAP) was measured in microdialysates as a marker of protease activation.

RESULTS

Intraperitoneal glycerol levels and the ratio of lactate to pyruvate were higher after PD and glucose levels were lower in seven patients who later developed symptomatic POPF than in eight patients with other surgical complications (OSC) and 33 with no surgical complications (NSC) (all P < 0·050). TAP was detected at a concentration greater than 0·1 µg/l in six of seven patients with POPF, two of eight with OSC and two of 33 with NSC. Intraperitoneal lactate concentrations were higher than systemic levels in all patients on days 1 to 5 after surgery (P < 0·001). In patients with POPF, high intraperitoneal lactate concentrations were observed without systemic hyperlactataemia.

CONCLUSION

Early in the postoperative phase, patients who later developed clinically significant POPF had higher intraperitoneal glycerol concentrations and lactate/pyruvate ratios, and lower glucose concentrations in combination with a TAP level exceeding 0·1 µg/l close to the PJA, than patients who did not develop POPF.

Alcohol consumption and gastric cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

BACKGROUND

Gastric cancer (GC) is the second leading cause of cancer death worldwide. The association between alcohol consumption and GC has been investigated in numerous epidemiologic studies with inconsistent results.

OBJECTIVE

We evaluated the association between alcohol consumption and GC risk.

DESIGN

We conducted a prospective analysis in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, which included 444 cases of first primary gastric adenocarcinoma. HRs and 95% CIs for GC were estimated by using multivariable Cox proportional hazards regression for consumption of pure ethanol in grams per day, with stratification by smoking status, anatomic subsite (cardia, noncardia), and histologic subtype (diffuse, intestinal). In a subset of participants, results were further adjusted for baseline Helicobacter pylori serostatus.

RESULTS

Heavy (compared with very light) alcohol consumption (≥60 compared with 0.1-4.9 g/d) at baseline was positively associated with GC risk (HR: 1.65; 95% CI: 1.06, 2.58), whereas lower consumption amounts (<60 g/d) were not. When we analyzed GC risk by type of alcoholic beverage, there was a positive association for beer (≥30 g/d; HR: 1.75; 95% CI: 1.13, 2.73) but not for wine or liquor. Associations were primarily observed at the highest amounts of drinking in men and limited to noncardia subsite and intestinal histology; no statistically significant linear dose-response trends with GC risk were observed.

CONCLUSION

Heavy (but not light or moderate) consumption of alcohol at baseline (mainly from beer) is associated with intestinal-type noncardia GC risk in men from the EPIC cohort.

Aberrant DNA methylation of cancer-associated genes in gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST)

Epigenetic events have emerged as key mechanisms in the regulation of critical biological processes and in the development of a wide variety of human malignancies, including gastric cancer (GC), however precise gene targets of aberrant DNA methylation in GC remain largely unknown. Here, we have combined pyrosequencing-based quantitative analysis of DNA methylation in 98 GC cases and 64 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort and in cancer tissue and non-tumorigenic adjacent tissue of an independent series of GC samples. A panel of 10 cancer-associated genes (CHRNA3, DOK1, MGMT, RASSF1A, p14ARF, CDH1, MLH1, ALDH2, GNMT and MTHFR) and LINE-1 repetitive elements were included in the analysis and their association with clinicopathological characteristics (sex, age at diagnosis, anatomical sub-site, histological sub-type) was examined. Three out of the 10 genes analyzed exhibited a marked hypermethylation, whereas two genes (ALDH2 and MTHFR) showed significant hypomethylation, in gastric tumors. Among differentially methylated genes, we identified new genes (CHRNA3 and DOK1) as targets of aberrant hypermethylation in GC, suggesting that epigenetic deregulation of these genes and their corresponding cellular pathways may promote the development and progression of GC. We also found that global demethylation of tumor cell genomes occurs in GC, consistent with the notion that abnormal hypermethylation of specific genes occurs concomitantly with genome-wide hypomethylation. Age and gender had no significant influence on methylation states, but an association was observed between LINE-1 and MLH1 methylation levels with histological sub-type and anatomical sub-site. This study identifies aberrant methylation patters in specific genes in GC thus providing information that could be exploited as novel biomarkers in clinics and molecular epidemiology of GC.

Pre-diagnostic levels of anionic trypsinogen, cationic trypsinogen, and pancreatic secretory trypsin inhibitor in relation to pancreatic cancer risk

BACKGROUND/AIMS

Experimental studies have suggested that trypsinogen may enhance tumor progression and that the ratio between anionic trypsinogen and cationic trypsinogen (HAT/HCT) and between the sum of trypsinogens and pancreatic secretory trypsin inhibitor (PSTI) ((HAT + HCT)/PSTI) are disturbed in patients with pancreatic cancer. The aim of this study was to investigate if pre-diagnostic levels of these parameters are associated with subsequent pancreatic cancer risk.

METHODS

A total of 33,346 subjects participated in a health screening programme in Malmö, Sweden. Pancreatic cancer cases (n = 84) were matched to three controls each. HAT, HCT and PSTI were analyzed in pre-diagnostic serum samples. Odds ratios for pancreatic cancer were calculated using logistic regression and were then stratified for other risk factors.

RESULTS

In the main analysis, a statistically significant association between the ratio between HAT/HCT and pancreatic cancer was observed for all, for the crude OR and for the ORs adjusted for sex, BMI or Helicobacter pylori. When stratified for sex, statistically significant associations were found for females in the crude OR and for the ORs adjusted for time to analysis, BMI, alcohol consumption or H. pylori. There was a positive association between the ratio of HAT/HCT to pancreatic cancer in the intermediate/high alcohol consumption group and subjects with a BMI <25. The sum of trypsinogens showed a similar pattern, but was only of borderline significance in the intermediate/high alcohol consumption group.

CONCLUSION

Our hypothesis predicted an increased risk for pancreatic cancer related to an imbalance between trypsin activity and trypsin inhibition capacity. The findings concerning the ratio of HAT/HCT are in line with this. The results related to analyses stratified for other risk factors should be considered as mainly explorative.