Association of pancreatic Fatty infiltration with pancreatic ductal adenocarcinoma

Independent association between prediabetes and future pancreatic fat accumulation: a 5-year Japanese cohort study

BACKGROUND

The association between pancreatic fat and glucose dysmetabolism has been reported in several cross-sectional studies; however, a recent longitudinal study showed that baseline pancreatic fat did not cause subsequent diabetes mellitus. We hypothesized that pancreatic fat is not a cause but a manifestation of glucose dysmetabolism and aimed to investigate the association between baseline prediabetes and future pancreatic fat accumulation.

METHODS

Between 2008 and 2015, 198 nondiabetic participants, who underwent a health check-up via unenhanced computed tomography (CT) twice with CT intervals ≥ 5 years, were enrolled as prediabetes (n = 48) and non-prediabetes participants (n = 150). Prediabetes was defined as fasting plasma glucose of 100-125 mg/dl or hemoglobin A1c of 5.7-6.4%. Pancreatic fat was evaluated using a histologically validated method to measure the difference between pancreas and spleen attenuations (P-S) on CT. Pancreatic fat accumulation during follow-up was measured as P-S change from baseline. Multiple linear regression was used to evaluate the association between baseline prediabetes and future pancreatic fat accumulation with adjustment for age, sex, body mass index, physical activity, and liver fat at baseline.

RESULTS

Mean pancreatic fat accumulation was 0.30 (SD, 5.8) Hounsfield units during follow-up. On univariate analysis, baseline prediabetes was associated with future pancreatic fat accumulation (β = 3.73; 95% CI 1.91-5.55; P < 0.001). This association remained statistically significant on multivariate analysis (β = 3.14; 95% CI 1.25-5.03; P = 0.001).

CONCLUSIONS

Prediabetes is a risk factor for future pancreatic fat accumulation. Pancreatic fat may be a manifestation of glucose dysmetabolism.

Deficiencies in Natural Killer Cell Numbers, Expansion, and Function at the Pre-Neoplastic Stage of Pancreatic Cancer by KRAS Mutation in the Pancreas of Obese Mice

The combined/synergistic effect of genetic mutation of KRAS in the pancreas and obesity, a life-style factor on suppression of natural killer (NK) cells at the pre-neoplastic stage of pancreatic cancer has not been investigated and is the subject of this report. Obese mice with KRAS (KC) mutation in the pancreas fed with high-fat calorie diet (HFCD) exhibit severe deficiencies in the NK cell expansion and function at the pre-neoplastic stage of pancreatic cancer. Decreased NK cell-mediated cytotoxicity is observed in the peripheral blood, spleen, pancreas, and peri-pancreatic adipose tissue in obese KC mice, whereas in bone marrow an increased NK cell-mediated cytotoxicity is observed when compared to lean WT mice fed with control diet (CD). Obese KC mice on HFCD demonstrated the least ability to expand NK cells or induce NK cell-mediated cytotoxicity when compared to the other groups of mice. Indeed, the following profile WT/CD > WT/HFCD > KC/CD > KC/HFCD was seen for the ability to expand NK cells or mediate cytotoxicity among four groups of mice in spleen, peripheral blood, pancreas, and peri-pancreatic adipose tissue. Sorted NK cells from the splenocytes of four groups of mice also exhibited the same profiles for the cytotoxicity as the unsorted splenocytes, and a decreased IFN-γ secretion could be seen in cultures of NK cells from KC mice fed with either CD or HFCD. Cultures of NK cells with autologous monocytes from obese KC mice fed with HFCD exhibited decreased cytotoxicity and IFN-γ secretion, whereas cultures of allogeneic NK cells from WT mice fed with CD with osteoclasts of obese mice fed with HFCD demonstrated decreased cytotoxicity but augmented IFN-γ secretion. Increased IL-6 along with decreased IFN-γ and cell-mediated cytotoxicity by the NK cells, within NK-adipose tissue of KC/HFCD mice, may provide safe microenvironment for the expansion of pancreatic tumors.

Activated Ductal Proliferation Induced by N-Nitrosobis (2-oxopropyl)amine in Fat-infiltrated Pancreas of KK-Ay Mice

BACKGROUND/AIM

Our aim was to investigate whether tissue with fatty infiltration within the lobes of the pancreas (scattered FI) is sensitive to carcinogen-induced pancreatic ductal proliferation.

MATERIALS AND METHODS

Seven-week-old female C57BL/6J, C57BL/6J-Ay, KK-Ay, and ICR mice were subcutaneously treated with N-nitrosobis(2-oxopropyl) amine at a dose of 80 mg/kg body weight, and the differences in damage-induced cell proliferation and their biochemical data were compared 2 days after.

RESULTS

Scattered FI in the pancreas was obvious only in KK-Ay mice, which have high serum lipid, leptin and insulin levels, and cell proliferation both in pancreatic and common bile ducts was enhanced only in KK-Ay mice by the carcinogen treatment.

CONCLUSION

Scattered FI in the pancreas per se can be an important factor for carcinogenesis. The genetic background causing scattered FI of the pancreas should be further investigated.

Adipocytes WNT5a mediated dedifferentiation: a possible target in pancreatic cancer microenvironment

A significant epidemiological association between obesity and pancreatic ductal adenocarcinoma (PDAC) has previously been described, as well as a correlation between the degree of pancreatic steatosis, PDAC risk and prognosis. The underlying mechanisms are still not completely known.

After co-culture of 3T3-L1 adipocytes and MiaPaCa2 with an in vitro transwell system we observed the appearance of fibroblast-like cells, along with a decrease in number and size of remaining adipocytes. RT-PCR analyses of 3T3-L1 adipocytes in co-culture showed a decrease in gene expression of typical markers of mature adipocytes, in parallel with an increased expression of fibroblast-specific and reprogramming genes. We found an increased WNT5a gene and protein expression early in MiaPaCa2 cells in co-culture. Additionally, EMSA of c-Jun and AP1 in 3T3-L1 demonstrated an increased activation in adipocytes after co-culture. Treatment with WNT5a neutralizing antibody completely reverted the activation of c-Jun and AP1 observed in co-cultured adipocytes.

Increasing doses of recombinant SFRP-5, a competitive inhibitor for WNT5a receptor, added to the co-culture medium, were able to block the dedifferentiation of adipocytes in co-culture.

These data support a WNT5a-mediated dedifferentiation process with adipocytes reprogramming toward fibroblast-like cells that might profoundly influence cancer microenvironment.

Non-alcoholic fatty pancreas disease as a risk factor for pancreatic cancer based on endoscopic ultrasound examination among pancreatic cancer patients: A single-center experience

Background and Aim

Non‐alcoholic fatty pancreas disease (NAFPD) is a disease that ranges from simple steatosis and can further lead to chronic pancreatitis and possible pancreatic cancer development. Its exact pathogenesis and impact on clinical practice are still largely unknown. Pancreatic cancer is still the most lethal malignancy in the world. Studies about the relationship between NAFPD and pancreatic cancer are still lacking. This study aims to find the possible role of endoscopic ultrasound (EUS) examination as a screening tool in NAFPD patients based on EUS examination among pancreatic cancer patients.

Methods

EUS hospital data were collected within a 2‐year period, and all patients who underwent EUS procedures were analyzed. Pancreatic malignancy was diagnosed based on imaging and tumor markers and cytopathology using the endoscopic ultrasound fine needle aspiration (EUS‐FNA) procedure. Patients with pre‐existing pancreatic diseases, significant alcohol consumption, or other primary cancer with metastasis to the pancreas were excluded. Statistical analysis was performed using SPSS version 23.0.

Results

In total, 162 patients (75 females and 87 males) were recruited for database analysis.^ Pancreatic malignancy was found in 43 (26.5%) patients, whereas fatty pancreas was found in 53 (32.7%) patients, and this was commonly found among pancreatic cancer patients.^ Based on logistic regression analysis, factors such as age, gender, diabetes, and chronic pancreatitis were not found to be significant risk factors for pancreatic malignancy where fatty pancreas is the only significant risk factor for pancreatic cancer (odds ratio: 18.027 [95% CI: 7.288–44.588]).

Conclusion

Prevalence of NAFPD among pancreatic cancer patients is high. Future studies can be conducted to show whether EUS can be considered a screening tool for the early detection of pancreatic malignancy in NAFPD patients; a cohort prospective study might also be needed to show clear causality between fatty pancreas and pancreatic cancer.

Adipocytes and Neutrophils Give a Helping Hand to Pancreatic Cancers

Obesity-induced inflammation can build up a confined microenvironment in pancreatic adenocarcinoma that is associated with increased desmoplasia, neutrophil recruitment, reduced delivery of chemotherapeutic drugs, and immune evasion. Targeting molecular pathways empowering this circuit might represent a necessary measure to reach clinical efficacy for combination therapies in patients with excess body weight. Cancer Discov; 6(8); 821-3. ©2016 AACR.See related article by Incio et al., p. 852.

The Clinical Implications of Fatty Pancreas: A Concise Review

Fatty pancreas is a newly recognized condition which is poorly investigated until today as compared to nonalcoholic fatty liver disease. It is characterized by pancreatic fat accumulation and subsequent development of pancreatic and metabolic complications. Association of fatty pancreas have been described with type 2 diabetes mellitus, acute and chronic pancreatitis and even pancreatic carcinoma. In this review article, we provide an update on clinical implications, pathogenesis, diagnosis, treatment and outcomes.

Pancreas Fat and β Cell Mass in Humans With and Without Diabetes: An Analysis in the Japanese Population

CONTEXT

The mechanisms by which β cell mass is reduced in patients with type 2 diabetes remain unclear. It has been postulated that ectopic fat deposits in the pancreas induce β cell apoptosis, leading to the development of diabetes.

OBJECTIVE

The aim of this study was to clarify the effects of intrapancreatic fat on β and α cell mass in humans with and without diabetes.

DESIGN AND SUBJECTS

Using our tissue database, pancreas sections of 72 Japanese nondiabetic (NDM) autopsy cases and 50 diabetic and 49 age- and body mass index (BMI)-matched NDM patients who underwent pancreatic surgery were analyzed. In addition to histological grading, intrapancreatic fat area (IPFA) was quantified as fractional intralobular, but not interlobular, fat area to the whole pancreas area.

RESULTS

Although IPFA was positively correlated with age and BMI, there was no significant difference in IPFA between cases with and without diabetes. Moreover, no association was found between IPFA and either β or α cell area, or glycated hemoglobin.

CONCLUSION

These findings suggest that pancreatic fat deposits have little effect on β cell mass and the development of diabetes in humans.

Crosstalk between stromal cells and cancer cells in pancreatic cancer: New insights into stromal biology

Pancreatic cancer (PC) remains one of the most lethal malignancies worldwide. Increasing evidence has confirmed the pivotal role of stromal components in the regulation of carcinogenesis, invasion, metastasis, and therapeutic resistance in PC. Interaction between neoplastic cells and stromal cells builds a specific microenvironment, which further modulates the malignant properties of cancer cells. Instead of being a "passive bystander", stroma may play a role as a "partner in crime" in PC. However, the role of stromal components in PC is complex and requires further investigation. In this article, we review recent advances regarding the regulatory roles and mechanisms of stroma biology, especially the cellular components such as pancreatic stellate cells, macrophages, neutrophils, adipocytes, epithelial cells, pericytes, mast cells, and lymphocytes, in PC. Crosstalk between stromal cells and cancer cells is thoroughly investigated. We also review the prognostic value and molecular therapeutic targets of stroma in PC. This review may help us further understand the molecular mechanisms of stromal biology and its role in PC development and therapeutic resistance. Moreover, targeting stroma components may provide new therapeutic strategies for this stubborn disease.

Statins and pancreatic cancer

Pancreatic cancer remains among the most lethal cancers, despite ongoing advances in treatment for all stages of the disease. Disease prevention represents another opportunity to improve patient outcome, with metabolic syndrome and its components, such as diabetes, obesity and dyslipidemia, having been recognized as modifiable risk factors for pancreatic cancer. In addition, statins have been shown to potentially reduce pancreatic cancer risk and to improve survival in patients with a combination of metabolic syndrome and pancreatic cancer. Furthermore, preclinical studies have demonstrated that statins exhibit antitumor effects in pancreatic cancer cell lines in vitro and animal models in vivo, in addition to delaying the progression of pancreatic intraepithelial neoplasia to pancreatic ductal adenocarcinoma (PDAC) and inhibiting PDAC formation in conditional K-Ras mutant mice. The mechanisms by which statins produce anticancer effects remain poorly understood, although appear to involve inhibition of the mevalonate/cholesterol synthesis pathway, thus blocking the synthesis of intermediates important for prenylation and activation of the Ras/mitogen-activated protein kinase 1 signaling pathway. Furthermore, statins have been identified to modulate the phosphoinositide 3-kinase/Akt serine/threonine kinase 1 and inflammation signaling pathways, and to alter the expression of genes involved in lipid metabolism, which are important for PDAC growth and proliferation. In addition, statins have been demonstrated to exhibit further antitumor mechanisms in a number of other cancer types, which are beyond the scope of the present review. In the present review, current evidence highlighting the potential of statins as chemopreventive agents in pancreatic cancer is presented, and the antitumor mechanisms of statins elucidated thus far in this disease are discussed.

Fatty Pancreas: Should We Be Concerned?

The metabolic consequences of visceral fat deposition are well known, and the presence of intrapancreatic fat (IPF) has been recognized for decades. However, our knowledge about the distribution of fat in the pancreas and its clinical implications is in a nascent stage. Various terms have been proposed to describe IPF; for the purpose of this narrative review, we chose the general term fatty pancreas. Herein, we describe the radiologic, endoscopic, and histopathologic aspects of diagnosing fatty pancreas and provide an overview of the diseases associated with this condition. Our purpose is to highlight diagnostic challenges and identify specific clinical questions that would benefit from further study. As evident in this review, IPF is associated with various metabolic diseases, pancreatitis, pancreatic cancer, and precancer-yet establishing causality needs careful, further study.

Obesity and Cancer: An Angiogenic and Inflammatory Link

With the current epidemic of obesity, a large number of patients diagnosed with cancer are overweight or obese. Importantly, this excess body weight is associated with tumor progression and poor prognosis. The mechanisms for this worse outcome, however, remain poorly understood. We review here the epidemiological evidence for the association between obesity and cancer, and discuss potential mechanisms focusing on angiogenesis and inflammation. In particular, we will discuss how the dysfunctional angiogenesis and inflammation occurring in adipose tissue in obesity may promote tumor progression, resistance to chemotherapy, and targeted therapies such as anti-angiogenic and immune therapies. Better understanding of how obesity fuels tumor progression and therapy resistance is essential to improve the current standard of care and the clinical outcome of cancer patients. To this end, we will discuss how an anti-diabetic drug such as metformin can overcome these adverse effects of obesity on the progression and treatment resistance of tumors.

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.

Impact of obesity on surgical outcomes of laparoscopic distal pancreatectomy: A Norwegian single-center study

BACKGROUND

Obesity is known as a risk factor for intra- and postoperative complications in pancreatic operation. However, the operative outcomes in obese patients undergoing laparoscopic distal pancreatectomy remain unclear.

METHODS

A total number of 423 patients underwent laparoscopic distal pancreatectomy at Oslo University Hospital-Rikshospitalet from April 1997 to December 2015. Patients were categorized into 3 groups based on the body mass index: normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), and obese (≥30 kg/m²). After excluding underweight patients, 402 patients were enrolled in this study.

RESULTS

Obese patients had significantly longer operative time and increased blood loss compared with overweight and normal weight patients (190 [61-480] minutes vs 158 [56-520] minutes vs 153 [29-374] minutes, P = .009 and 200 [0-2,800] mL vs 50 [0-6250] mL vs 90 [0-2,000] mL, P = .01, respectively). A multiple linear regression analysis identified obesity as predictive of prolonged operative time and increased blood loss during laparoscopic distal pancreatectomy. The rates of clinically relevant pancreatic fistula and severe complications (≥grade III by Accordion classification) were comparable in the 3 groups (P = .23 and P = .37, respectively). A multivariate logistic regression model did not demonstrate an association between obesity and postoperative morbidity (P = .09). The duration of hospital stay was comparable in the 3 groups (P = .13).

CONCLUSION

In spite of longer operative time and greater blood loss, laparoscopic distal pancreatectomy in obese patients is associated with satisfactory postoperative outcomes, similar to those in normal weight and overweight patients. Hence, laparoscopic distal pancreatectomy should be equally considered both in obese and nonobese patients.

Obesity-Induced Inflammation and Desmoplasia Promote Pancreatic Cancer Progression and Resistance to Chemotherapy

It remains unclear how obesity worsens treatment outcomes in patients with pancreatic ductal adenocarcinoma (PDAC). In normal pancreas, obesity promotes inflammation and fibrosis. We found in mouse models of PDAC that obesity also promotes desmoplasia associated with accelerated tumor growth and impaired delivery/efficacy of chemotherapeutics through reduced perfusion. Genetic and pharmacologic inhibition of angiotensin-II type-1 receptor reverses obesity-augmented desmoplasia and tumor growth and improves response to chemotherapy. Augmented activation of pancreatic stellate cells (PSC) in obesity is induced by tumor-associated neutrophils (TAN) recruited by adipocyte-secreted IL1β. PSCs further secrete IL1β, and inactivation of PSCs reduces IL1β expression and TAN recruitment. Furthermore, depletion of TANs, IL1β inhibition, or inactivation of PSCs prevents obesity-accelerated tumor growth. In patients with pancreatic cancer, we confirmed that obesity is associated with increased desmoplasia and reduced response to chemotherapy. We conclude that cross-talk between adipocytes, TANs, and PSCs exacerbates desmoplasia and promotes tumor progression in obesity.

SIGNIFICANCE

Considering the current obesity pandemic, unraveling the mechanisms underlying obesity-induced cancer progression is an urgent need. We found that the aggravation of desmoplasia is a key mechanism of obesity-promoted PDAC progression. Importantly, we discovered that clinically available antifibrotic/inflammatory agents can improve the treatment response of PDAC in obese hosts. Cancer Discov; 6(8); 852-69. ©2016 AACR.See related commentary by Bronte and Tortora, p. 821This article is highlighted in the In This Issue feature, p. 803.

Genetics and biology of pancreatic ductal adenocarcinoma

Ying et al. review pancreatic ductal adenocarcinoma (PDAC) genetics and biology, particularly altered cancer cell metabolism, the complexity of immune regulation in the tumor microenvironment, and impaired DNA repair processes.

With 5-year survival rates remaining constant at 6% and rising incidences associated with an epidemic in obesity and metabolic syndrome, pancreatic ductal adenocarcinoma (PDAC) is on track to become the second most common cause of cancer-related deaths by 2030. The high mortality rate of PDAC stems primarily from the lack of early diagnosis and ineffective treatment for advanced tumors. During the past decade, the comprehensive atlas of genomic alterations, the prominence of specific pathways, the preclinical validation of such emerging targets, sophisticated preclinical model systems, and the molecular classification of PDAC into specific disease subtypes have all converged to illuminate drug discovery programs with clearer clinical path hypotheses. A deeper understanding of cancer cell biology, particularly altered cancer cell metabolism and impaired DNA repair processes, is providing novel therapeutic strategies that show strong preclinical activity. Elucidation of tumor biology principles, most notably a deeper understanding of the complexity of immune regulation in the tumor microenvironment, has provided an exciting framework to reawaken the immune system to attack PDAC cancer cells. While the long road of translation lies ahead, the path to meaningful clinical progress has never been clearer to improve PDAC patient survival.

Prevalence of Non-Alcoholic Fatty Pancreas Disease (NAFPD) and its risk factors among adult medical check-up patients in a private hospital: a large cross sectional study

BACKGROUND

The clinical significance of non-alcoholic fatty pancreatic disease (NAFPD) or fatty pancreas is largely unknown. It is often an incidental finding on abdominal ultrasound, which is not explored further, especially its association with metabolic condition and the risk of pancreatic malignancy. The aim of this study is to evaluate the presence of NAFPD and its associated risk factors among adult medical check-up patients.

METHOD

A large cross-sectional study was done among adult medical check-up patients underwent abdominal ultrasound between January and December 2013 in Medistra Hospital, Jakarta. Data was obtained from the patients' medical record and include demographic data, blood pressures, fasting blood glucose level, and lipid profile. The presence of fatty pancreas was diagnosed by ultrasound. Bivariate and multivariate analyses were done to find associated risk factors for NAFPD. Statistical analysis was done using SPSS version 17.

RESULTS

A total of 1054 cases were included in this study; pancreas cannot be visualized in 153 cases and were excluded from the analysis. Fatty pancreas was present in 315 (35.0%) patients. Bivariate analyses found associations among fatty pancreas and several risk factors such as gender, age, systolic and diastolic blood pressures, body mass index (BMI), fasting plasma glucose (FPG), triglycerides (TG) and cholesterol levels.

CONCLUSION

Fatty pancreas is a common finding during medical check-up with a prevalence of 35%. Fatty pancreas has significant association with metabolic factors and it might have an important role in risk of malignancy.

Metformin Reduces Desmoplasia in Pancreatic Cancer by Reprogramming Stellate Cells and Tumor-Associated Macrophages

Background

Pancreatic ductal adenocarcinoma (PDAC) is a highly desmoplastic tumor with a dismal prognosis for most patients. Fibrosis and inflammation are hallmarks of tumor desmoplasia. We have previously demonstrated that preventing the activation of pancreatic stellate cells (PSCs) and alleviating desmoplasia are beneficial strategies in treating PDAC. Metformin is a widely used glucose-lowering drug. It is also frequently prescribed to diabetic pancreatic cancer patients and has been shown to associate with a better outcome. However, the underlying mechanisms of this benefit remain unclear. Metformin has been found to modulate the activity of stellate cells in other disease settings. In this study, we examine the effect of metformin on PSC activity, fibrosis and inflammation in PDACs.

Methods/Results

In overweight, diabetic PDAC patients and pre-clinical mouse models, treatment with metformin reduced levels of tumor extracellular matrix (ECM) components, in particular hyaluronan (HA). In vitro, we found that metformin reduced TGF-ß signaling and the production of HA and collagen-I in cultured PSCs. Furthermore, we found that metformin alleviates tumor inflammation by reducing the expression of inflammatory cytokines including IL-1β as well as infiltration and M2 polarization of tumor-associated macrophages (TAMs) in vitro and in vivo. These effects on macrophages in vitro appear to be associated with a modulation of the AMPK/STAT3 pathway by metformin. Finally, we found in our preclinical models that the alleviation of desmoplasia by metformin was associated with a reduction in ECM remodeling, epithelial-to-mesenchymal transition (EMT) and ultimately systemic metastasis.

Conclusion

Metformin alleviates the fibro-inflammatory microenvironment in obese/diabetic individuals with pancreatic cancer by reprogramming PSCs and TAMs, which correlates with reduced disease progression. Metformin should be tested/explored as part of the treatment strategy in overweight diabetic PDAC patients.

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.

Adiposity and cancer risk: new mechanistic insights from epidemiology

Excess body adiposity, commonly expressed as body mass index (BMI), is a risk factor for many common adult cancers. Over the past decade, epidemiological data have shown that adiposity-cancer risk associations are specific for gender, site, geographical population, histological subtype and molecular phenotype. The biological mechanisms underpinning these associations are incompletely understood but need to take account of the specificities observed in epidemiology to better inform future prevention strategies.

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.

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.

Potential ability of xanthophylls to prevent obesity-associated cancer

Obesity-associated cancers, including colon cancer and breast cancer, are increasing in Asian countries with Westernized lifestyles as exemplified by reduced physical activity and increased fat/sugar consumption. An excessive accumulation of visceral adipose tissue causes insulin resistance, dyslipidemia and adipocytokine imbalance, and these factors are suggested to be involved in cancer promotion. To prevent obesity-associated cancers, researcher attention is increasing on the so-called “functional foods”. In addition, new approaches to cancer control are in high demand, and using “functional foods” as supplemental or adjuvant agents in chemotherapy is thought to be a promising approach. One of these functional ingredients is xanthophylls, which are natural fat-soluble pigments found in fruits, vegetables, algae and other plants. Xanthophylls belong to the carotenoid class and have structures containing oxygen. Some studies have revealed that xanthophylls improve the inflammation status, serum triglyceride levels, blood pressure levels and liver function test values. Furthermore, recent studies show that xanthophylls possess high anti-cancer, anti-diabetic, anti-obesity and anti-oxidant properties. In this review, we highlight the recent findings for five xanthophylls, namely astaxanthin, β-cryptoxanthin, fucoxanthin, neoxanthin and zeaxanthin/lutein, and their relevance to cancer prevention.

Fat, epigenome and pancreatic diseases. Interplay and common pathways from a toxic and obesogenic environment

The worldwide obesity epidemic is paralleled by a rise in the incidence of pancreatic disorders ranging from "fatty" pancreas to pancreatitis and cancer. Body fat accumulation and pancreatic dysfunctions have common pathways, mainly acting through insulin resistance and low-grade inflammation, frequently mediated by the epigenome. These mechanisms are affected by lifestyle and by the toxic effects of fat and pollutants. An early origin is common, starting in pediatric age or during the fetal life in response to nutritional factors, endocrine disruptor chemicals (EDCs) or parental exposure to toxics. A "fatty pancreas" is frequent in obese and is able to induce pancreatic damage. The fat is a target of EDCs and of the cytotoxic/mutagenic effects of heavy metals, and is the site of bioaccumulation of lipophilic and persistent pollutants related with insulin resistance and able to promote pancreatic cancer. Increased Body Mass Index (BMI) can act as independent risk factor for a more severe course of acute pancreatitis and obesity is also a well-known risk factor for pancreatic cancer, that is related with BMI, insulin resistance, and duration of exposure to the toxic effects of fat and/or of environmental pollutants. All these mechanisms involve gene-environment interactions through epigenetic factors, and might be manipulated by primary prevention measures. Further studies are needed, pointing to better assess the interplays of modifiable factors on both obesity and pancreatic diseases, and to verify the efficacy of primary prevention strategies involving lifestyle and environmental exposure to toxics.