Enhancement of carcinogenesis and fatty infiltration in the pancreas in N-nitrosobis(2-oxopropyl)amine-treated hamsters by high-fat diet

High prevalence of pancreatic steatosis in pancreatic cancer patients: A meta-analysis and systematic review

OBJECTIVE

In the last decade there has been increasing interest in defining pancreatic steatosis (PS) and establishing its association with pancreatic ductal adenocarcinoma (PDAC). However, no consensus guidelines have yet been published on the management of PS. In this systematic review and meta-analysis performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we investigated the association between PS and PDAC.

DESIGN

Medical literature between 2007 and 2023 was reviewed for eligible trials investigating the prevalence of PS in patients with PDAC. Eligible studies reporting on PS, assessed via imaging or histology, were included. The primary objective was to determine the association between PDAC and PS by comparing the prevalence of PS in individuals with- and without PDAC. Secondary, an evaluation was conducted to establish whether the method of assessment correlated with the association of PDAC and PS, and the prevalence of PDAC in individuals with PS. Measures of effect size were determined using odds ratios (ORs) and corresponding 95 % confidence intervals (95 % CI).

RESULTS

The systematic review identified a total of 23 studies, of which seventeen studies examined PS prevalence among PDAC patients and were included in the meta-analysis. Overall, the pooled prevalence of PS in patients with PDAC was 53.6 % (95 % CI 40.9-66.2). No significant difference in PS prevalence was observed across various diagnostic methods or geographical regions. Overall, the pooled OR for PS in patients with PDAC compared to controls was 3.23 (95 % CI 1.86-5.60).

CONCLUSIONS

PDAC patients have a high prevalence of PS, and they are significantly more likely to have PS compared to controls. These findings emphasize the need to prioritize a standardized approach to the diagnosis, follow-up, and treatment of PS, with future studies focusing on identifying patients who would benefit from PDAC surveillance programs.

Comparative analysis of leptin and carcinoembryonic antigen-related cell adhesion molecule 1 plasma expression in pancreatic cancer and chronic pancreatitis patients

Compared to the general population, patients with chronic pancreatitis have an up to 12-fold higher risk of developing pancreatic cancer. The aim of our study was the identification of potential proteomic biomarkers to contribute to the detection of pancreatic cancer among patients with chronic pancreatitis. We initially performed a proteomic screening analysis of 105 analytes on plasma pools. To validate this finding, we quantitatively determined leptin concentrations in individual plasma samples using the ELISA technique. Additionally, we explored the plasma expression of CEACAM1, an important regulator of leptin expression in various cancer cells using the same method. The preliminary semi-quantitative proteomic analysis identified leptin as the only protein with substantially higher expression in patients with pancreatic cancer compared to those with chronic pancreatitis. Subsequently, by quantitative ELISA, we determined a higher median leptin concentration in the plasma of patients with pancreatic cancer compared to those with chronic pancreatitis. The statistical significance was maintained regardless of other variables like BMI or gender. Additionally, we explored the plasma expression of CEACAM1, an important regulator of leptin expression in various cancer cells, in order to provide insights into the complex mechanisms underlying pancreatic cancer and chronic pancreatits. CEACAM1 concentrations were higher in the plasma of the patients with pancreatic cancer than in those with chronic pancreatitis. However, we did not find a statistically significant correlation between leptin and CEACAM1 expression variation in the two study groups, with CEACAM1 concentration also dependent on other parameters such as BMI, gender, and serum triglyceride level. In conclusion, leptin seems to be a biomarker that can contribute to differentiate patients with pancreatic cancer from patients with chronic pancreatitis.

Dietary fat and lipid metabolism in the tumor microenvironment

Metabolic reprogramming has been considered a core hallmark of cancer, in which excessive accumulation of lipids promote cancer initiation, progression and metastasis. Lipid metabolism often includes the digestion and absorption of dietary fat, and the ways in which cancer cells utilize lipids are often influenced by the complex interactions within the tumor microenvironment. Among multiple cancer risk factors, obesity has a positive association with multiple cancer types, while diets like calorie restriction and fasting improve health and delay cancer. Impact of these diets on tumorigenesis or cancer prevention are generally studied on cancer cells, despite heterogeneity of the tumor microenvironment. Cancer cells regularly interact with these heterogeneous microenvironmental components, including immune and stromal cells, to promote cancer progression and metastasis, and there is an intricate metabolic crosstalk between these compartments. Here, we focus on discussing fat metabolism and response to dietary fat in the tumor microenvironment, focusing on both immune and stromal components and shedding light on therapeutic strategies surrounding lipid metabolic and signaling pathways.

Decoding the obesity-cancer connection: lessons from preclinical models of pancreatic adenocarcinoma

Obesity is a metabolic state of energy excess and a risk factor for over a dozen cancer types. Because of the rising worldwide prevalence of obesity, decoding the mechanisms by which obesity promotes tumor initiation and early progression is a societal imperative and could broadly impact human health. Here, we review results from preclinical models that link obesity to cancer, using pancreatic adenocarcinoma as a paradigmatic example. We discuss how obesity drives cancer development by reprogramming the pretumor or tumor cell and its micro- and macro-environments. Specifically, we describe evidence for (1) altered cellular metabolism, (2) hormone dysregulation, (3) inflammation, and (4) microbial dysbiosis in obesity-driven pancreatic tumorigenesis, denoting variables that confound interpretation of these studies, and highlight remaining gaps in knowledge. Recent advances in preclinical modeling and emerging unbiased analytic approaches will aid in further unraveling the complex link between obesity and cancer, informing novel strategies for prevention, interception, and therapy in pancreatic adenocarcinoma and other obesity-associated cancers.

Fatty Pancreas Is a Risk Factor for Pancreatic Cancer: A Systematic Review and Meta-Analysis of 2956 Patients

Pancreatic cancer (PC) is one of the most lethal cancers worldwide. Recently, fatty pancreas (FP) has been studied thoroughly, and although its relationship to PC is not fully understood, FP is suspected to contribute to the development of PC. We aimed to assess the association between PC and FP by conducting a systematic review and meta-analysis. We systematically searched three databases, MEDLINE, Embase, and CENTRAL, on 21 October 2022. Case-control and cross-sectional studies reporting on patients where the intra-pancreatic fat deposition was determined by modern radiology or histology were included. As main outcome parameters, FP in patients with and without PC and PC in patients with and without FP were measured. Proportion and odds ratio (OR) with a 95% confidence interval (CI) were used for effect size measure. PC among patients with FP was 32% (OR 1.32; 95% CI 0.42-4.16). However, the probability of having FP among patients with PC was more than six times higher (OR 6.13; 95% CI 2.61-14.42) than in patients without PC, whereas the proportion of FP among patients with PC was 0.62 (95% CI 0.42-0.79). Patients identified with FP are at risk of developing PC. Proper screening and follow-up of patients with FP may be recommended.

Fatty infiltration of the pancreas: a systematic concept analysis

Fatty infiltration of the pancreas (FIP) has been recognized for nearly a century, yet many aspects of this condition remain unclear. Regular literature reviews on the diagnosis, consequences, and management of FIP are crucial. This review article highlights the various disorders for which FIP has been established as a risk factor, including type 2 diabetes mellitus (T2DM), pancreatitis, pancreatic fistula (PF), metabolic syndrome (MS), polycystic ovary syndrome (PCOS), and pancreatic duct adenocarcinoma (PDAC), as well as the new investigation tools. Given the interdisciplinary nature of FIP research, a broad range of healthcare specialists are involved. This review article covers key aspects of FIP, including nomenclature and definition of pancreatic fat infiltration, history and epidemiology, etiology and pathophysiology, clinical presentation and diagnosis, clinical consequences, and treatment. This review is presented in a detailed narrative format for accessibility to clinicians and medical students.

Fatty pancreas was associated with a higher acute pancreatitis Systemic Inflammatory Response Syndrome score at hospital admission

BACKGROUND

Pancreatic fat infiltration was shown to be linked with acute pancreatitis and probably its severity. These interesting findings merit more investigation to elucidate the effect of fatty pancreas on acute pancreatitis severity.

METHODS

We performed a retrospective study of patients hospitalized with documented acute pancreatitis. Pancreatic fat was determined according to pancreas attenuation on computed tomography. Patients were divided into two groups, with and without fatty pancreas. The Systemic Inflammatory Response Syndrome (SIRS) score was compared.

RESULTS

Overall, 409 patients were hospitalized with acute pancreatitis. Among them, 48 patients had fatty pancreas (group A), vs. 361 patients who did not (group B). The mean ± SD age in group A was 54.6 ± 21.3, vs. 57.6 ± 16.8 in group B ( P  = 0.51). Patients in group A, had a significantly higher rate of fatty liver, as compared to group B (85.4% vs. 35.5%, P  < 0.001). There was no significant difference in the medical history among the two groups. Fatty pancreas was associated with more severe acute pancreatitis as assessed by SIRS score at admission. The mean ± SD of SIRS score was significantly higher in group A (0.92 ± 0.87), as compared to 0.59 ± 0.74 in group B ( P  = 0.009). Positive SIRS score was present in a significantly higher proportion of patients with fatty pancreas (25%), as compared to only 11.4% in group B ( P  = 0.02).

CONCLUSION

The occurrence of acute pancreatitis with higher SIRS score was significantly associated with fatty pancreas. Fatty pancreas may represent a predictor of acute pancreatitis severity.

Fatty change of the pancreas: the Pandora's box of pancreatology

Prevention of common diseases of the pancreas or interception of their progression is as attractive in theory as it is elusive in practice. The fundamental challenge has been an incomplete understanding of targets coupled with a multitude of intertwined factors that are associated with the development of pancreatic diseases. Evidence over the past decade has shown unique morphological features, distinctive biomarkers, and complex relationships of intrapancreatic fat deposition. Fatty change of the pancreas has also been shown to affect at least 16% of the global population. This knowledge has solidified the pivotal role of fatty change of the pancreas in acute pancreatitis, chronic pancreatitis, pancreatic cancer, and diabetes. The pancreatic diseases originating from intrapancreatic fat (PANDORA) hypothesis advanced in this Personal View cuts across traditional disciplinary boundaries with a view to tackling these diseases. New holistic understanding of pancreatic diseases is well positioned to propel pancreatology through lasting research breakthroughs and clinical advances.

Mechanisms of obesity- and diabetes mellitus-related pancreatic carcinogenesis: a comprehensive and systematic review

Research on obesity- and diabetes mellitus (DM)-related carcinogenesis has expanded exponentially since these two diseases were recognized as important risk factors for cancers. The growing interest in this area is prominently actuated by the increasing obesity and DM prevalence, which is partially responsible for the slight but constant increase in pancreatic cancer (PC) occurrence. PC is a highly lethal malignancy characterized by its insidious symptoms, delayed diagnosis, and devastating prognosis. The intricate process of obesity and DM promoting pancreatic carcinogenesis involves their local impact on the pancreas and concurrent whole-body systemic changes that are suitable for cancer initiation. The main mechanisms involved in this process include the excessive accumulation of various nutrients and metabolites promoting carcinogenesis directly while also aggravating mutagenic and carcinogenic metabolic disorders by affecting multiple pathways. Detrimental alterations in gastrointestinal and sex hormone levels and microbiome dysfunction further compromise immunometabolic regulation and contribute to the establishment of an immunosuppressive tumor microenvironment (TME) for carcinogenesis, which can be exacerbated by several crucial pathophysiological processes and TME components, such as autophagy, endoplasmic reticulum stress, oxidative stress, epithelial-mesenchymal transition, and exosome secretion. This review provides a comprehensive and critical analysis of the immunometabolic mechanisms of obesity- and DM-related pancreatic carcinogenesis and dissects how metabolic disorders impair anticancer immunity and influence pathophysiological processes to favor cancer initiation.

A Macrophage Membrane-Polymer Hybrid Biomimetic Nanoplatform for Therapeutic Delivery of Somatostatin Peptide to Chronic Pancreatitis

The clinical translation of therapeutic peptides is generally challenged by multiple issues involving absorption, distribution, metabolism and excretion. In this study, a macrophage membrane-coated poly(lactic-co-glycolic acid) (PLGA) nanodelivery system was developed to enhance the bioavailability of the somatostatin (SST) peptide, which faces the hurdles of short half-life and potential side effects in the treatment of chronic pancreatitis. Using a facile nanoprecipitation strategy, SST was loaded in the nanoparticles with an encapsulation efficiency (EE) and a loading efficiency (LE) of 73.68 ± 3.56% and 1.47 ± 0.07%, respectively. The final formulation of SST-loaded nanoparticles with the camouflage of macrophage membrane (MP-SST) showed a mean diameter of 151 ± 4 nm and an average zeta potential of −29.6 ± 0.3 mV, which were stable long term during storage. With an above 90% cell viability, a hemolysis level of about 2% (<5%) and a preference for being ingested by activated endothelial cells compared to macrophages, the membrane−polymer hybrid nanoparticle showed biocompatibility and targeting capability in vitro. After being intravenously administered to mice with chronic pancreatitis, the MP-SST increased the content of SST in the serum (123.6 ± 13.6 pg/mL) and pancreas (1144.9 ± 206.2 pg/g) compared to the treatment of (Dulbecco’s phosphate-buffered saline) DPBS (61.7 ± 6.0 pg/mL in serum and 740.2 ± 172.4 pg/g in the pancreas). The recovery of SST by MP-SST downregulated the expressions of chronic pancreatitis-related factors and alleviated the histologic severity of the pancreas to the greatest extent compared to other treatment groups. This augmentation of SST therapeutic effects demonstrated the superiority of integrating the synthetic polymer with biological membranes in the design of nanoplatforms for advanced and smart peptide delivery. Other peptides like SST can also be delivered via the membrane−polymer hybrid nanosystem for the treatment of diseases, broadening and promoting the potential clinical applications of peptides as therapeutics.

Consumption of two meals per day is associated with increased intrapancreatic fat deposition in patients with type 2 diabetes: a retrospective study

INTRODUCTION

This study aimed to identify the associations between lifestyle factors and intrapancreatic fat deposition in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

The participants were 185 patients with type 2 diabetes who were hospitalized at Osaka University Hospital between 2008 and 2020 and underwent abdominal CT during hospitalization. Information regarding lifestyle factors, including the number of meals consumed per day, snacking habits, exercise habits, exercise at work, smoking habits, alcohol intake, insomnia, sleep apnea syndrome, and night-shift working, was acquired from self-administered questionnaires or medical records. We measured the mean CT values for the pancreas (P), liver (L), and spleen (S), and the visceral fat area (VFA), and quantified intrapancreatic and liver ectopic fat accumulation as P-S and L-S, respectively.

RESULTS

After adjustment for age, sex, hemoglobin A1c, and body mass index (BMI), participants who consumed two meals per day had significantly lower P-S (higher intrapancreatic fat deposition, p=0.02) than those who consumed three meals per day. There were no significant associations between the number of meals consumed and liver ectopic fat accumulation and VFA (p=0.73 and p=0.67, respectively).

CONCLUSIONS

Patients with diabetes who consumed two meals per day showed greater intrapancreatic fat deposition than those who consumed three meals per day, even after adjustment for BMI. These findings support the current guideline for diabetes treatment that skipping meals should be avoided.

Rapid acceleration of KRAS-mutant pancreatic carcinogenesis via remodeling of tumor immune microenvironment by PPARδ

Pancreatic intraepithelial neoplasia (PanIN) is a precursor of pancreatic ductal adenocarcinoma (PDAC), which commonly occurs in the general populations with aging. Although most PanIN lesions (PanINs) harbor oncogenic KRAS mutations that initiate pancreatic tumorigenesis; PanINs rarely progress to PDAC. Critical factors that promote this progression, especially targetable ones, remain poorly defined. We show that peroxisome proliferator-activated receptor-delta (PPARδ), a lipid nuclear receptor, is upregulated in PanINs in humans and mice. Furthermore, PPARδ ligand activation by a high-fat diet or GW501516 (a highly selective, synthetic PPARδ ligand) in mutant KRASG12D (KRASmu) pancreatic epithelial cells strongly accelerates PanIN progression to PDAC. This PPARδ activation induces KRASmu pancreatic epithelial cells to secrete CCL2, which recruits immunosuppressive macrophages and myeloid-derived suppressor cells into pancreas via the CCL2/CCR2 axis to orchestrate an immunosuppressive tumor microenvironment and subsequently drive PanIN progression to PDAC. Our data identify PPARδ signaling as a potential molecular target to prevent PDAC development in subjects harboring PanINs.

Magnetic resonance imaging-derived fat fraction predicts risk of malignancy in intraductal papillary mucinous neoplasm

PURPOSE

Assess the relationship between MRI-derived pancreatic fat fraction and risk of malignancy in intraductal papillary mucinous neoplasm (IPMN).

METHODS

MRIs of patients with IPMN who underwent pancreaticoduodenectomy were analyzed. IPMN with low-grade dysplasia (n = 29) were categorized as low-risk while IPMN at high risk of malignancy consisted of those with high-grade dysplasia/invasive carcinoma (n = 33). Pancreatic fat-fraction (FFmean) was measured using the 2-point Dixon-method. Images were evaluated for the high-risk stigmata and worrisome features according to the revised 2017 Fukuoka consensus criteria. Data on serum CA19-9, Diabetes Mellitus (DM) status, body mass index (BMI), and histological chronic pancreatitis were obtained.

RESULTS

A significant difference in FFmean was found between the high-risk IPMN (11.45%) and low-risk IPMN (9.95%) groups (p = 0.027). Serum CA19-9 level (p = 0.021), presence of cyst wall enhancement (p = 0.029), and solid mass (p = 0.008) were significantly associated with high-risk IPMN. There was a significant correlation between FFmean and mural nodule size (r = 0.36, p ˂ 0.01), type 2 DM (r = 0.34, p ˂ 0.01), age (r = 0.31, p ˂ 0.05), serum CA 19-9 (r = 0.30, p ˂ 0.05), cyst diameter (r = 0.30, p ˂ 0.05), and main pancreatic duct diameter (r = 0.26, p ˂ 0.05). Regression analysis revealed FFmean (OR 1.103, p = 0.035) as an independent predictive variable of high-risk IPMN.

CONCLUSION

FFmean is significantly associated with high-risk IPMN and an independent predictor of IPMN malignant risk. FFmean may have clinical utility as a biomarker to complement the current IPMN treatment algorithm and improve clinical decision making regarding the need for surgical resection or surveillance.

Fatty Pancreas Represents a Risk Factor for Acute Pancreatitis: A Pilot Study

OBJECTIVES

Fatty pancreas (FP), previously believed to be without clinical significance, recently has been shown to be associated with comorbid diseases. We aimed to explore whether FP predispose to acute pancreatitis.

METHODS

Patients who underwent endoscopic ultrasound for hepatobiliary indications were included. Patients with pathological pancreato-biliary findings other than FP were excluded. The cohort was divided into patients with a history of pancreatitis (within 6 months of endoscopic ultrasound, group A) and patients without (group B).

RESULTS

Overall, 189 patients were included. Sixty-one (32.3%) patients were in group A, and 128 (67.7%) patients were in group B. The average age in group A was 55.5 (standard deviation, 17.7) versus 58.5 (standard deviation, 13.5) in group B. The prevalence of FP in group A (37.7%) was higher compared with group B (4.7%) (P = 0.001). On univariate analysis, FP showed significant correlation with a history of acute pancreatitis [odds ratio (OR), 5.14, P = 0.006] and hyperlipidemia (OR, 4.19; P = 0.002). On multivariate analysis, FP remained significantly associated with a history of acute pancreatitis after stratification for obesity and hyperlipidemia (OR, 10.78; 95% confidence interval, 3.75-30.89; P < 0.0001).

CONCLUSIONS

Fatty pancreas was associated with acute pancreatitis. Clinicians should be aware of this association.

Anti-Allergic Drug Suppressed Pancreatic Carcinogenesis via Down-Regulation of Cellular Proliferation

Pancreatic cancer is a fatal disease, and thus its chemoprevention is an important issue. Based on the recent report that patients with allergic diseases have a low risk for pancreatic cancer, we examined the potential chemopreventive effect of anti-allergic agents using a hamster pancreatic carcinogenesis model. Among the three anti-allergic drugs administered, montelukast showed a tendency to suppress the incidence of pancreatic cancer. Further animal study revealed a significantly decreased incidence of pancreatic cancer in the high-dose montelukast group compared with controls. The development of the pancreatic intraepithelial neoplasia lesions was also significantly suppressed. The Ki-67 labeling index was significantly lower in pancreatic carcinomas in the high-dose montelukast group than in controls. In vitro experiments revealed that montelukast suppressed proliferation of pancreatic cancer cells in a dose-dependent manner with decreased expression of phospho-ERK1/2. Montelukast induced G1 phase arrest. Conversely, leukotriene D₄ (LTD₄), an agonist of CYSLTR1, increased cellular proliferation of pancreatic cancer cells with an accumulation of phospho-ERK1/2. In our cohort, pancreatic ductal adenocarcinoma patients with high CYSLTR1 expression showed a significantly unfavorable clinical outcome compared with those with low expression. Our results indicate that montelukast exerts a chemopreventive effect on pancreatic cancer via the LTD₄–CYSLTR1 axis and has potential for treatment of pancreatic carcinogenesis.

DPYD, down-regulated by the potentially chemopreventive agent luteolin, interacts with STAT3 in pancreatic cancer

The 5-year survival rate of pancreatic ductal carcinoma (PDAC) patients is <10% despite progress in clinical medicine. Strategies to prevent the development of PDAC are urgently required. The flavonoids Luteolin (Lut) and hesperetin (Hes) may be cancer-chemopreventive, but effects on pancreatic carcinogenesis in vivo have not been studied. Here, the chemopreventive effects of Lut and Hes on pancreatic carcinogenesis are assessed in the BOP-induced hamster PDAC model. Lut but not Hes suppressed proliferation of pancreatic intraepithelial neoplasia (PanIN) and reduced the incidence and multiplicity of PDAC in this model. Lut also inhibited the proliferation of hamster and human pancreatic cancer cells in vitro. Multi-blot and microarray assays revealed decreased phosphorylated STAT3 (pSTAT3) and dihydropyrimidine dehydrogenase (DPYD) on Lut exposure. To explore the relationship between DPYD and STAT3 activity, the former was silenced by RNAi or overexpressed using expression vectors, and the latter was inactivated by small molecule inhibitors or stimulated by IL6 in human PDAC cells. DPYD knock-down decreased, and overexpression increased, pSTAT3 and cell proliferation. DPYD expression was decreased by inactivation of STAT3 and increased by its activation. The frequency of pSTAT3-positive cells and DPYD expression was significantly correlated and was decreased in parallel by Lut in the hamster PDAC model. Finally, immunohistochemical analysis in 73 cases of human PDAC demonstrated that DPYD expression was positively correlated with the Ki-67 labeling index, and high expression was associated with poor prognosis. These results indicate that Lut is a promising chemopreventive agent for PDAC, targeting a novel STAT3-DPYD pathway.

Pancreatic Tumorigenesis: Oncogenic KRAS and the Vulnerability of the Pancreas to Obesity

Simple Summary

Pancreatic cancer is a devastating disease with a poor survival rate, and oncogenic mutant KRAS is a major driver of its initiation and progression; however, effective strategies/drugs targeting major forms of mutant KRAS have not been forthcoming. Of note, obesity is known to worsen mutant KRAS-mediated pathologies, leading to PDAC with high penetrance; however, the mechanistic link between obesity and pancreatic cancer remains elusive. The recent discovery of FGF21 as an anti-obesity and anti-inflammation factor and as a downstream target of KRAS has shed new light on the problem.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and KRAS (Kirsten rat sarcoma 2 viral oncogene homolog) mutations have been considered a critical driver of PDAC initiation and progression. However, the effects of mutant KRAS alone do not recapitulate the full spectrum of pancreatic pathologies associated with PDAC development in adults. Historically, mutant KRAS was regarded as constitutively active; however, recent studies have shown that endogenous levels of mutant KRAS are not constitutively fully active and its activity is still subject to up-regulation by upstream stimuli. Obesity is a metabolic disease that induces a chronic, low-grade inflammation called meta-inflammation and has long been recognized clinically as a major modifiable risk factor for pancreatic cancer. It has been shown in different animal models that obesogenic high-fat diet (HFD) and pancreatic inflammation promote the rapid development of mutant KRAS-mediated PDAC with high penetrance. However, it is not clear why the pancreas with endogenous levels of mutant KRAS is vulnerable to chronic HFD and inflammatory challenges. Recently, the discovery of fibroblast growth factor 21 (FGF21) as a novel anti-obesity and anti-inflammatory factor and as a downstream target of mutant KRAS has shed new light on this problem. This review is intended to provide an update on our knowledge of the vulnerability of the pancreas to KRAS-mediated invasive PDAC in the context of challenges engendered by obesity and associated inflammation.

Pancreatic Fat Infiltration Is Associated with a Higher Risk of Pancreatic Ductal Adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) has a poor survival rate, partly due to delayed diagnosis. Identifying high-risk individuals could lead to early detection and improve survival. A number of risk factors such as alcohol consumption and metabolic syndrome are associated with fatty infiltration of the pancreas. Experimental models show that a fatty pancreas promotes tissue inflammation and fibrosis, which could promote PDAC.

Methods

We conducted a case-control study in a single-university tertiary hospital. Sixty-eight PDAC cases with recent non-contrast computed tomography (CT) and 235 controls were studied. The controls had no history of malignancy and underwent CT colonography for cancer screening in the same period. Pancreatic fat was estimated by calculating pancreatic (P) attenuation, corrected to splenic (S) attenuation, measured in three 1.0-cm² regions of the pancreas. The P.S100 value calculated was used to estimate fatty infiltration of the pancreas (FIP), with a lower P.S100 representing a higher FIP.

Results

The PDAC patients had a lower BMI and a higher rate of type 2 diabetes mellitus. The P.S100 was lower in cases than in controls (86.452 vs. 92.414, p = 4.016e-06), suggesting that FIP is higher with PDAC. The risk of developing PDAC steadily increased significantly for the quartiles with a higher FIP compared to the low FIP quartile. No correlation between BMI and FIP (r = -0.1031179; 95% confidence interval [CI] -0.22267106 to 0.01949092) was found. Adjusting for confounders (age, sex, BMI, and DM), the risk of developing PDAC according to the FIP was estimated to be 3.75 (95% CI 1.9234408-7.993337; p = 0.000171). FIP was stable before and after the diagnosis of PDAC in 9 cases with prior CT scans when no pancreatic tumor was identifiable.

Conclusion

Fatty pancreas is associated with an increased risk of pancreatic cancer. Once confirmed in larger-scale studies, these findings could help to identify at-risk individuals, particularly in high-risk groups such as chronic alcohol consumers.

Increased dietary fatty acids determine the fatty-acid profiles of human pancreatic cancer cells and their carrier's plasma, pancreas and liver

Primary contents of dietary fat are three or four types of fatty acids, namely saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), n6-polyunsaturated fatty acid (n6PUFA) and, to less extent, n3-polyunsaturated fatty acid (n3PUFA). Previous studies suggest that increased SFA, MUFA, and n6PUFA in high fat diets (HFDs) stimulate the origination, growth, and liver metastasis of pancreatic cancer cells, whereas increased n3PUFA has the opposite effects. It is unclear whether the fatty acid-induced effects are based on changed fatty-acid composition of involved cells. Here, we investigated whether increased SFA, MUFA, n6PUFA, and n3PUFA in different HFDs determine the FA profiles of pancreatic cancer cells and their carrier's plasma, pancreas, and liver. We transplanted MiaPaCa2 human pancreatic cancer cells in athymic mice and fed them normal diet or four HFDs enriched with SFA, MUFA, n6PUFA, and n3PUFA, respectively. After 7 weeks, fatty acids were profiled in tumor, plasma, pancreas, and liver, using gas chromatography. When tumor carriers were fed four HFDs, the fatty acids that were increased dietarily were also increased in the plasma. When tumor carriers were fed MUFA-, n6PUFA-, and n3PUFA-enriched HFDs, the dietarily increased fatty acids were also increased in tumor, pancreas, and liver. When tumor-carriers were fed the SFA-enriched HFD featuring lauric and myristic acids (C12:0 and C14:0), tumor, pancreas, and liver showed an increase not in the same SFAs but palmitic acid (C16:0) and/or stearic acid (C18:0). In conclusion, predominant fatty acids in HFDs determine the fatty-acid profiles of pancreatic cancer cells and their murine carriers.

Head and Body/Tail Pancreatic Carcinomas Are Not the Same Tumors

The association between pancreatic ductal adenocarcinoma (PDAC) location (head vs. Body/Tail (B/T)) and clinical outcome remains controversial. We collected clinicopathological and gene expression data from 249 resected PDAC samples from public data sets, and we compared data between 208 head and 41 B/T samples. The 2-year overall survival (OS) was better for the head than for the B/T PDACs (44 vs. 27%, p = 0.043), especially when comparing tumors with similar TNM classification (T3/4N0M0: 67% vs. 17%, p = 0.002) or from the same molecular class (squamous subtype: 31% vs. 0%, p < 0.0001). Bailey's molecular subtypes were differentially distributed within the two groups, with the immunogenic subtype being underrepresented in the "B/T" group (p = 0.005). Uni- and multivariate analyses indicated that PDAC anatomic location was an independent prognostic factor. Finally, the supervised analysis identified 334 genes differentially expressed. Genes upregulated in the "head" group suggested lymphocyte activation and pancreas exocrine functions. Genes upregulated in the "B/T" group were related to keratinocyte differentiation, in line with the enrichment for squamous phenotype. We identified a robust gene expression signature (GES) associated with B/T PDAC location, suggesting that head and B/T PDAC are different. This GES could serve as an indicator for differential therapeutic management based on PDAC location.

Fatty pancreas: A possible risk factor for pancreatic cancer in animals and humans

Obesity, type 2 diabetes mellitus (T2DM) and aging are associated with pancreatic cancer risk, but the mechanisms of pancreatic cancer development caused by these factors are not clearly understood. Syrian golden hamsters are susceptible to N‐nitrosobis(2‐oxopropyl)amine (BOP)‐induced pancreatic carcinogenesis. Aging, BOP treatment and/or a high‐fat diet cause severe and scattered fatty infiltration (FI) of the pancreas with abnormal adipokine production and promote pancreatic ductal adenocarcinoma (PDAC) development. The KK‐A^y mouse, a T2DM model, also develops severe and scattered FI of the pancreas. Treatment with BOP induced significantly higher cell proliferation in the pancreatic ducts of KK‐A^y mice, but not in those of ICR and C57BL/6J mice, both of which are characterized by an absence of scattered FI. Thus, we hypothesized that severely scattered FI may be involved in the susceptibility to PDAC development. Indeed, severe pancreatic FI, or fatty pancreas, is observed in humans and is associated with age, body mass index (BMI) and DM, which are risk factors for pancreatic cancer. We analyzed the degree of FI in the non‐cancerous parts of PDAC and non‐PDAC patients who had undergone pancreatoduodenectomy by histopathology and demonstrated that the degree of pancreatic FI in PDAC cases is significantly higher than that in non‐PDAC controls. Moreover, the association with PDAC is positive, even after adjusting for BMI and the prevalence of DM. Accumulating evidence suggests that pancreatic FI is involved in PDAC development in animals and humans, and further investigations to clarify the genetic and environmental factors that cause pancreatic FI are warranted.

Exploring the metabolic syndrome: Nonalcoholic fatty pancreas disease

After the first description of fatty pancreas in 1933, the effects of pancreatic steatosis have been poorly investigated, compared with that of the liver. However, the interest of research is increasing. Fat accumulation, associated with obesity and the metabolic syndrome (MetS), has been defined as “fatty infiltration” or “nonalcoholic fatty pancreas disease” (NAFPD). The term “fatty replacement” describes a distinct phenomenon characterized by death of acinar cells and replacement by adipose tissue. Risk factors for developing NAFPD include obesity, increasing age, male sex, hypertension, dyslipidemia, alcohol and hyperferritinemia. Increasing evidence support the role of pancreatic fat in the development of type 2 diabetes mellitus, MetS, atherosclerosis, severe acute pancreatitis and even pancreatic cancer. Evidence exists that fatty pancreas could be used as the initial indicator of “ectopic fat deposition”, which is a key element of nonalcoholic fatty liver disease and/or MetS. Moreover, in patients with fatty pancreas, pancreaticoduodenectomy is associated with an increased risk of intraoperative blood loss and post-operative pancreatic fistula.

Leptin signaling enhances cell invasion and promotes the metastasis of human pancreatic cancer via increasing MMP-13 production

Emerging evidence has suggested that leptin, an adipokine related to energy homeostasis, plays a role in cancer growth and metastasis. However, its impact on pancreatic cancer is rarely studied. In this study, we found that leptin's functional receptor Ob-Rb was expressed in pancreatic cancer cell lines. Treatment with leptin enhanced the migration and invasion of pancreatic cancer cells but did not affect the proliferation of human pancreatic cancer cells. Leptin up-regulated the expression of matrix metalloproteinase-13 (MMP-13) via the JAK2/STAT3 signaling pathway. The overexpression of leptin was shown to significantly promote tumor growth and lymph node metastasis in a subcutaneous model and an orthotopic model of human pancreatic cancer, respectively. Furthermore, in human pancreatic cancer tissues, the expression of Ob-Rb was positively correlated with the MMP-13 level. The increased expression of either Ob-Rb or MMP-13 was significantly associated with lymph node metastasis and tended to be associated with the TNM stage in patients with pancreatic cancer. Our findings suggest that leptin enhances the invasion of pancreatic cancer through the increase in MMP-13 production, and targeting the leptin/MMP-13 axis could be an attractive therapeutic strategy for pancreatic cancer.

Chemopreventive effect of resveratrol and apocynin on pancreatic carcinogenesis via modulation of nuclear phosphorylated GSK3β and ERK1/2

Despite progress in clinical cancer medicine in multiple fields, the prognosis of pancreatic cancer has remained dismal. Recently, chemopreventive strategies using phytochemicals have gained considerable attention as an alternative in the management of cancer. The present study aimed to evaluate the chemopreventive effects of resveratrol (RV) and apocynin (AC) in N-Nitrosobis(2-oxopropyl)amine-induced pancreatic carcinogenesis in hamster. RV- and AC-treated hamsters showed significant reduction in the incidence of pancreatic cancer with a decrease in Ki-67 labeling index in dysplastic lesions. RV and AC suppressed cell proliferation of human and hamster pancreatic cancer cells by inhibiting the G1 phase of the cell cycle with cyclin D1 downregulation and inactivation of AKT-GSK3β and ERK1/2 signaling. Further, decreased levels of GSK3β(Ser9) and ERK1/2 phosphorylation and cyclin D1 expression in the nuclear fraction were observed in cells treated with RV or AC. Nuclear expression of phosphorylated GSK3β(Ser9) was also decreased in dysplastic lesions and adenocarcinomas of hamsters treated with RV or AC in vivo. These results suggest that RV and AC reduce phosphorylated GSK3β(Ser9) and ERK1/2 in the nucleus, resulting in inhibition of the AKT-GSK3β and ERK1/2 signaling pathways and cell cycle arrest in vitro and in vivo. Taken together, the present study indicates that RV and AC have potential as chemopreventive agents for pancreatic cancer.

Diet and Pancreatic Cancer Prevention

Pancreatic cancer is without any doubt the malignancy with the poorest prognosis and the lowest survival rate. This highly aggressive disease is rarely diagnosed at an early stage and difficult to treat due to its resistance to radiotherapy and chemotherapy. Therefore, there is an urgent need to clarify the causes responsible for pancreatic cancer and to identify preventive strategies to reduce its incidence in the population. Some circumstances, such as smoking habits, being overweight and diabetes, have been identified as potentially predisposing factors to pancreatic cancer, suggesting that diet might play a role. A diet low in fat and sugars, together with a healthy lifestyle, regular exercise, weight reduction and not smoking, may contribute to prevent pancreatic cancer and many other cancer types. In addition, increasing evidence suggests that some food may have chemo preventive properties. Indeed, a high dietary intake of fresh fruit and vegetables has been shown to reduce the risk of developing pancreatic cancer, and recent epidemiological studies have associated nut consumption with a protective effect against it. Therefore, diet could have an impact on the development of pancreatic cancer and further investigations are needed to assess the potential chemo preventive role of specific foods against this disease. This review summarizes the key evidence for the role of dietary habits and their effect on pancreatic cancer and focuses on possible mechanisms for the association between diet and risk of pancreatic cancer.

Circulating Leptin and Risk of Pancreatic Cancer: A Pooled Analysis From 3 Cohorts

Adiposity is associated with pancreatic cancer; however, the underlying mechanism(s) is uncertain. Leptin is an adipokine involved in metabolic regulation, and obese individuals have higher concentrations. We conducted a pooled, nested case-control study of cohort participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, and the Cancer Prevention Study II Nutrition Cohort to investigate whether prediagnostic serum leptin was associated with pancreatic cancer. A total of 731 pancreatic adenocarcinoma cases that occurred between 1986 and 2010 were included (maximum follow-up, 23 years). Incidence density-selected controls (n = 909) were matched to cases by cohort, age, sex, race, and blood draw date. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals. Sex-specific quintiles were based on the distribution of the controls. Overall, serum leptin was not associated with pancreatic cancer (quintile 5 vs. quintile 1: odds ratio = 1.13, 95% confidence interval: 0.75, 1.71; Ptrend = 0.38). There was a significant interaction by follow-up time (P = 0.003), such that elevated risk was apparent only during follow-up of more than 10 years after blood draw (quintile 5 vs. quintile 1: odds ratio = 2.55, 95% confidence interval: 1.23, 5.27; Ptrend = 0.004). Our results support an association between increasing leptin concentration and pancreatic cancer; however, long follow-up is necessary to observe the relationship. Subclinical disease may explain the lack of association during early follow-up.

Obesity, Intrapancreatic Fatty Infiltration, and Pancreatic Cancer

Obesity and intrapancreatic fatty infiltration are associated with increased risk of pancreatic cancer and its precursor lesions. The interplay among obesity, inflammation, and oncogenic Kras signaling promotes pancreatic tumorigenesis. Targeting the interaction between obesity-associated inflammation and Kras signaling may provide new strategies for prevention and therapy of pancreatic cancer.

Biphasic Alterations in Expression and Subcellular Localization of MUC1 in Pancreatic Ductal Carcinogenesis in Syrian Hamsters

OBJECTIVES

The aim of the present study was to characterize molecular targets for the prevention/diagnosis of pancreatic cancer using a chemically induced hamster pancreatic carcinogenesis model, in which background injuries to the parenchyma, for example, chronic pancreatitis or acinar atrophy, are limited.

METHODS

Gene expression profiles in atypical hyperplasias were first investigated using a microarray technique. Immunohistochemical analyses of early lesions and invasive ductal carcinoma (IDC) were then conducted for MUC1, of which mRNA levels were prominent among the up-regulated genes, in contrast with the coexpression of epithelial-mesenchymal transition (EMT)-related proteins.

RESULTS

Immunohistochemistry for MUC1 cytoplasmic domain (MUC1-CD), which was not detected in normal-like pancreatic ducts, was positive in the apical surfaces of the epithelia of hyperplasias with and without atypia and IDC areas with distinct tubular patterns. In contrast, cytoplasmic/nuclear positivity for MUC1-CD was observed in the invasive front of IDCs. The coexpression of EMT-related proteins, such as slug and vimentin, with cytoplasmic/nuclear MUC1-CD was also detected.

CONCLUSIONS

Alterations in the expression and subcellular localization of MUC1 represent a biphasic phenomenon, and the latter may be associated with EMT in pancreatic carcinogenesis in hamsters, which indicates that changes in MUC1 are important targets for pancreatic cancer prevention and chemotherapy.

The effect of fatty pancreas on serum glucose parameters in patients with nonalcoholic steatohepatitis

OBJECTIVE

Fatty pancreas (FP) is related to obesity, and may have some clinical implications on glucose metabolism. The frequency and importance of FP in patients with nonalcoholic steatohepatitis (NASH) are not clear. This study aimed to investigate: the frequency of FP in patients with NASH, and its effects on serum glucose parameters.

METHODS

FP was detected and graded by transabdominal ultrasonography (USG) in patients with biopsy-proven NASH and healthy controls. Body Mass Index and waist circumference were recorded, and serum lipids, fasting serum glucose, HbA1c, OGTT 2-h, insulin level, insulin resistance, type 2 diabetes mellitus (DM) and prediabetes rates were detected.

RESULTS

Eighty-four subjects with NASH and 35 healthy controls were enrolled in the study. There was no FP in 41 (48.8%) of the NASH patients according to the study criteria. Forty-three of the NASH patients and 5 of the controls had different grades of fat in their pancreas (51.2% vs. 14%, p=0.001). The HbA1c and OGTT 2-h results were significantly higher in NASH patients with FP compared to those without FP (p=0.003 and p=0.018). The rates of both prediabetes and DM were also found to be significantly increased in NASH patients with FP (p=0.004). The mean waist circumference was higher in patients with FP (p=0.027). Grade of FP by USG showed no effect on study parameters in subgroup analysis.

CONCLUSION

FP is common in patients with NASH and increases the rate of prediabetes and DM. The coexistence of both NASH and FP has a further impact on glucose metabolism and DM frequency.

Association of pancreatic Fatty infiltration with pancreatic ductal adenocarcinoma

OBJECTIVES:

Fatty infiltration (FI) in the pancreas is positively correlated with high body mass index (BMI) or obesity, and the prevalence of diabetes mellitus (DM), which are well-known risk factors of pancreatic cancer. However, the association of FI in the pancreas with pancreatic cancer is unclear. Recently, we have shown that Syrian golden hamsters feature FI of the pancreas, the severity of which increases along with the progression of carcinogenesis induced by a chemical carcinogen. To translate the results to a clinical setting, we investigated whether FI in the pancreas is associated with pancreatic cancer in a series of patients who had undergone pancreatoduodenectomy.

METHODS:

In the series, we identified 102 cases with pancreatic ductal adenocarcinoma (PDAC) and 85 controls with cancers except for PDAC. The degree of FI was evaluated histopathologically from the area occupied by adipocytes in pancreas sections, and was compared between the cases and controls.

RESULTS:

The degree of FI in the pancreas was significantly higher in cases than in controls (median 26 vs. 15%, P<0.001) and positively associated with PDAC, even after adjustment for BMI, prevalence of DM and other confounding factors (odds ratio (OR), 6.1; P<0.001). BMI was identified as the most significantly associated factor with FI in the pancreas.

CONCLUSIONS:

There is a positive correlation between FI in the pancreas and pancreatic cancer.

The diversity between pancreatic head and body/tail cancers: clinical parameters and in vitro models

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) can be divided into head, body and tail cancers according to the anatomy. Distinctions in tissue composition, vascularization and innervations have been clearly identified between the head and body/tail of the pancreas both in embryological development and in histopathology. To understand the postulated genotype difference, we present comprehensive information on two PDAC cell lines as typical representatives originating from pancreatic head and body/tail cancers, respectively.

DATA SOURCE

In the present review, we compare the difference between pancreatic head and body/tail cancers regarding clinical parameters and introducing an in vitro model.

RESULTS

Increasing evidence has shown that tumors at different locations (head vs body/tail) display different clinical presentation (e.g. incidence, symptom), treatment efficiency (e.g. surgery, chemotherapy) and thus patient prognosis. However, the genetic or molecular diversity (e.g. mutations, microRNA) between the two subtypes of PDAC has not been elucidated so far. They present different chemo- and/or radio-resistance, extracellular matrix adhesion and invasiveness, as well as genetic profiles.

CONCLUSION

Genetic and tumor biological diversity exists in PDAC according to the tumor localization.

Dietary energy balance modulation of Kras- and Ink4a/Arf+/--driven pancreatic cancer: the role of insulin-like growth factor-I

New molecular targets and intervention strategies for breaking the obesity-pancreatic cancer link are urgently needed. Using relevant spontaneous and orthotopically transplanted murine models of pancreatic cancer, we tested the hypothesis that dietary energy balance modulation impacts pancreatic cancer development and progression through an insulin-like growth factor (IGF)-I-dependent mechanism. In LSL-Kras(G12D)/Pdx-1-Cre/Ink4a/Arf(lox/+) mice, calorie restriction versus overweight- or obesity-inducing diet regimens decreased serum IGF-I, tumoral Akt/mTOR signaling, pancreatic desmoplasia, and progression to pancreatic ductal adenocarcinoma (PDAC), and increased pancreatic tumor-free survival. Serum IGF-I, Akt/mTOR signaling, and orthotopically transplanted PDAC growth were decreased in liver-specific IGF-I-deficient mice (vs. wild-type mice), and rescued with IGF-I infusion. Thus, dietary energy balance modulation impacts spontaneous pancreatic tumorigenesis induced by mutant Kras and Ink4a deficiency, the most common genetic alterations in human pancreatic cancer. Furthermore, IGF-I and components of its downstream signaling pathway are promising mechanistic targets for breaking the obesity-pancreatic cancer link.

High-fat, high-calorie diet promotes early pancreatic neoplasia in the conditional KrasG12D mouse model

There is epidemiologic evidence that obesity increases the risk of cancers. Several underlying mechanisms, including inflammation and insulin resistance, are proposed. However, the driving mechanisms in pancreatic cancer are poorly understood. The goal of the present study was to develop a model of diet-induced obesity and pancreatic cancer development in a state-of-the-art mouse model, which resembles important clinical features of human obesity, for example, weight gain and metabolic disturbances. Offspring of Pdx-1-Cre and LSL-KrasG12D mice were allocated to either a high-fat, high-calorie diet (HFCD; ∼4,535 kcal/kg; 40% of calories from fats) or control diet (∼3,725 kcal/kg; 12% of calories from fats) for 3 months. Compared with control animals, mice fed with the HFCD significantly gained more weight and developed hyperinsulinemia, hyperglycemia, hyperleptinemia, and elevated levels of insulin-like growth factor I (IGF-I). The pancreas of HFCD-fed animals showed robust signs of inflammation with increased numbers of infiltrating inflammatory cells (macrophages and T cells), elevated levels of several cytokines and chemokines, increased stromal fibrosis, and more advanced PanIN lesions. Our results show that a diet high in fats and calories leads to obesity and metabolic disturbances similar to humans and accelerates early pancreatic neoplasia in the conditional KrasG12D mouse model. This model and findings will provide the basis for more robust studies attempting to unravel the mechanisms underlying the cancer-promoting properties of obesity, as well as to evaluate dietary- and chemopreventive strategies targeting obesity-associated pancreatic cancer development.

New-onset diabetes with a history of dyslipidemia predicts pancreatic cancer

OBJECTIVE

This study aimed to investigate whether the reported relationship between diabetes and pancreatic cancer (PC) could result from detection bias and whether dyslipidemia and/or new-onset diabetes (diagnosed within 1 year) could predict PC.

METHODS

A random sample of 1 million subjects covered by National Health Insurance was recruited. From 2003 to 2005, 495,493 men and 503,901 women without PC were followed up. Cox regression was used to evaluate the adjusted relative risk considering potential PC detection examinations and covariates.

RESULTS

Diabetic patients had a significantly higher probability of receiving examinations that might lead to PC diagnosis. In Cox proportional hazards regression models, diabetes was not a significant predictor, but dyslipidemia was significantly associated with an approximately 40% higher risk of PC. Age, living in more urbanized regions, and potential PC detection examinations were significant covariates. Patients with new-onset diabetes and previous dyslipidemia had a remarkably higher risk compared with those without either condition (relative risk [95% confidence interval], 2.512 [1.169-5.398]).

CONCLUSIONS

Dyslipidemia, but not diabetes, is a significant risk factor for PC. The link between diabetes and PC is likely due to confounders and detection bias. Patients with new-onset diabetes and a history of dyslipidemia are at an especially high risk of PC.

Involvement of inflammatory factors in pancreatic carcinogenesis and preventive effects of anti-inflammatory agents

Chronic inflammation is known to be a risk for many cancers, including pancreatic cancer. Heavy alcohol drinking and cigarette smoking are major causes of pancreatitis, and epidemiological studies have shown that smoking and chronic pancreatitis are risk factors for pancreatic cancer. Meanwhile, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are elevated in pancreatitis and pancreatic cancer tissues in humans and in animal models. Selective inhibitors of iNOS and COX-2 suppress pancreatic cancer development in a chemical carcinogenesis model of hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). In addition, hyperlipidemia, obesity, and type II diabetes are also suggested to be associated with chronic inflammation in the pancreas and involved in pancreatic cancer development. We have shown that a high-fat diet increased pancreatic cancer development in BOP-treated hamsters, along with aggravation of hyperlipidemia, severe fatty infiltration, and increased expression of adipokines and inflammatory factors in the pancreas. Of note, fatty pancreas has been observed in obese and/or diabetic cases in humans. Preventive effects of anti-hyperlipidemic/anti-diabetic agents on pancreatic cancer have also been shown in humans and animals. Taking this evidence into consideration, modulation of inflammatory factors by anti-inflammatory agents will provide useful data for prevention of pancreatic cancer.