Obesity, Intrapancreatic Fatty Infiltration, and Pancreatic Cancer

Pancreatic index: A prognostic factor of upfront surgery for body or tail pancreatic ductal adenocarcinoma with vascular involvement-A retrospective study

BACKGROUND

The pancreatic index (PI) is a useful preoperative imaging predictor for pancreatic ductal adenocarcinoma (PDAC). In this retrospective study, we determined the predictive effect of PI to distinguish patients of pancreatic body/tail cancer (PBTC) with vascular involvement who can benefit from upfront surgery.

METHOD

All patients who received distal pancreatectomy for PDAC from 2016 to 2020 at the Pancreatic Disease Center, Ruijin Hospital, Shanghai Jiaotong University School of Medicine were considered for the study. A total of 429 patients with PBTC were assessed in relation to the value of PI. Fifty-five patients were eventually included and divided into low PI group and 29 patients in the normal PI group.

RESULTS

The median overall survival (mOS) was significantly shorter in the low PI group (13.1 vs. 30.0 months, p = 0.002) in this study, and PI ≥ 0.78 (OR = 0.552, 95% CI: 0.301-0.904, p = 0.020) was an independent influencing factor confirmed by multivariate analysis. Subgroup analysis showed that PI was an independent prognostic factor for LA-PBTC (OR = 0.272, 95% CI: 0.077-0.969, p = 0.045). As for BR PBTC, PI (OR = 0.519, 95% CI: 0.285-0.947, p = 0.033) combined with carbohydrate antigen 125 (CA125) (OR = 2.806, 95% CI: 1.206-6.526, p = 0.017) and chemotherapy (OR = 0.327, 95% CI: 0.140-0.763, p = 0.010) were independent factors.

CONCLUSION

This study suggests that the PI can be used as a predictive factor to optimize the surgical indication for PBTC with vascular involvement. Preoperative patients with normal PI and CA125 can achieve a long-term prognosis comparable to that of resectable PBTC patients.

Overview of Pancreatic Cancer Epidemiology in Europe and Recommendations for Screening in High-Risk Populations

Pancreatic cancer is the seventh most common cause of death in the group of oncological diseases. Due to the asymptomatic course, early diagnosis is difficult. Currently, early detection methods are only used in high-risk groups. A literature review based on the available results of observational studies on patients with pancreatic cancer and people from high-risk groups was used to summarize the knowledge on risk factors. The GLOBOCAN 2020 data were used to assess the epidemiological situation in Europe. A summary of screening recommendations was prepared based on the available documents from medical organizations and associations. Pancreatic cancer risk factors are divided into two main groups: non-modifiable factors, e.g., hereditary factors and age, which increase the risk of developing this disease, and modifiable factors-BMI, smoking, and alcohol consumption. Hereditary factors account for 10% of pancreatic cancer cases. The highly specialized methods of early detection, (MRI, CT, or EUS) are used for screening high-risk populations. Of all the imaging methods, EUS is considered the most sensitive for pancreatic cancer and allows an accurate assessment of the size of even small lesions (<30 mm) and the extent of tumour infiltration into blood vessels. The available studies vary on the level of sensitivity and specificity of these methods for the diagnosis of pancreatic cancer. EUS, MRI, and CT are also expensive procedures and in some patients can be invasive, which is one of the arguments against the introduction of population screening programs based on imaging methods. Therefore, it is important to look for viable solutions that would improve early detection. This is important from the point of view of healthcare systems in Europe, where almost 29% of all global pancreatic cancer cases are reported.

Hematopoietic progenitor kinase 1 inhibits the development and progression of pancreatic intraepithelial neoplasia

Ras plays an essential role in the development of acinar-to-ductal metaplasia (ADM) and pancreatic ductal adenocarcinoma (PDAC). However, mutant Kras is an inefficient driver for PDAC development. The mechanisms of the switching from low Ras activity to high Ras activity that are required for development and progression of pancreatic intraepithelial neoplasias (PanINs) are unclear. In this study, we found that hematopoietic progenitor kinase 1 (HPK1) was upregulated during pancreatic injury and ADM. HPK1 interacted with the SH3 domain and phosphorylated Ras GTPase-activating protein (RasGAP) and upregulated RasGAP activity. Using transgenic mouse models of HPK1 or M46, a kinase-dead mutant of HPK1, we showed that HPK1 inhibited Ras activity and its downstream signaling and regulated acinar cell plasticity. M46 promoted the development of ADM and PanINs. Expression of M46 in KrasG12D Bac mice promoted the infiltration of myeloid-derived suppressor cells and macrophages, inhibited the infiltration of T cells, and accelerated the progression of PanINs to invasive and metastatic PDAC, while HPK1 attenuated mutant Kras-driven PanIN progression. Our results showed that HPK1 plays an important role in ADM and the progression of PanINs by regulating Ras signaling. Loss of HPK1 kinase activity promotes an immunosuppressive tumor microenvironment and accelerates the progression of PanINs to PDAC.

Diffuse pancreatic parenchymal atrophy, an imaging finding predictive of the development of pancreatic ductal adenocarcinoma: A case-control study

Background and Aim

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer, partly because its early detection is difficult. This study aimed to identify computed tomography (CT) findings associated with PDAC prior to diagnosis.

Methods

Past CT images were retrospectively collected from the PDAC group (n = 54) and the control group (n = 90). The following imaging findings were compared: pancreatic mass, main pancreatic duct (MPD) dilatation with or without cutoff, cyst, chronic pancreatitis with calcification, partial parenchymal atrophy (PPA), and diffuse parenchymal atrophy (DPA). In the PDAC group, CT findings were examined during the pre-diagnostic period and 6-36 months and 36-60 months before diagnosis. Multivariate analyses were performed using logistic regression.

Results

MPD dilatation with cutoff (P < 0.0001) and PPA (P = 0.023) were identified as significant imaging findings 6-36 months before diagnosis. DPA was identified as a novel imaging finding at 6-36 months (P = 0.003) and 36-60 months (P = 0.009) before diagnosis.

Conclusion

DPA, MPD dilatation with cutoff, and PPA were identified as imaging findings associated with pre-diagnostic PDAC.

The evolving view of thermogenic fat and its implications in cancer and metabolic diseases

The incidence of metabolism-related diseases like obesity and type 2 diabetes mellitus has reached pandemic levels worldwide and increased gradually. Most of them are listed on the table of high-risk factors for malignancy, and metabolic disorders systematically or locally contribute to cancer progression and poor prognosis of patients. Importantly, adipose tissue is fundamental to the occurrence and development of these metabolic disorders. White adipose tissue stores excessive energy, while thermogenic fat including brown and beige adipose tissue dissipates energy to generate heat. In addition to thermogenesis, beige and brown adipocytes also function as dynamic secretory cells and a metabolic sink of nutrients, like glucose, fatty acids, and amino acids. Accordingly, strategies that activate and expand thermogenic adipose tissue offer therapeutic promise to combat overweight, diabetes, and other metabolic disorders through increasing energy expenditure and enhancing glucose tolerance. With a better understanding of its origins and biological functions and the advances in imaging techniques detecting thermogenesis, the roles of thermogenic adipose tissue in tumors have been revealed gradually. On the one hand, enhanced browning of subcutaneous fatty tissue results in weight loss and cancer-associated cachexia. On the other hand, locally activated thermogenic adipocytes in the tumor microenvironment accelerate cancer progression by offering fuel sources and is likely to develop resistance to chemotherapy. Here, we enumerate current knowledge about the significant advances made in the origin and physiological functions of thermogenic fat. In addition, we discuss the multiple roles of thermogenic adipocytes in different tumors. Ultimately, we summarize imaging technologies for identifying thermogenic adipose tissue and pharmacologic agents via modulating thermogenesis in preclinical experiments and clinical trials.

Obesity and Pancreatic Cancer: Recent Progress in Epidemiology, Mechanisms and Bariatric Surgery

More than 30% of people in the United States (US) are classified as obese, and over 50% are considered significantly overweight. Importantly, obesity is a risk factor not only for the development of metabolic syndrome but also for many cancers, including pancreatic ductal adenocarcinoma (PDAC). PDAC is the third leading cause of cancer-related death, and 5-year survival of PDAC remains around 9% in the U.S. Obesity is a known risk factor for PDAC. Metabolic control and bariatric surgery, which is an effective treatment for severe obesity and allows massive weight loss, have been shown to reduce the risk of PDAC. It is therefore clear that elucidating the connection between obesity and PDAC is important for the identification of a novel marker and/or intervention point for obesity-related PDAC risk. In this review, we discussed recent progress in obesity-related PDAC in epidemiology, mechanisms, and potential cancer prevention effects of interventions, including bariatric surgery with preclinical and clinical studies.

Metabolic implications of pancreatic fat accumulation

Fat accumulation outside subcutaneous adipose tissue often has unfavourable effects on systemic metabolism. In addition to non-alcoholic fatty liver disease, which has received considerable attention, pancreatic fat has become an important area of research throughout the past 10 years. While a number of diagnostic approaches are available to quantify pancreatic fat, multi-echo Dixon MRI is currently the most developed method. Initial studies have shown associations between pancreatic fat and the metabolic syndrome, impaired glucose metabolism and type 2 diabetes mellitus. Pancreatic fat is linked to reduced insulin secretion, at least under specific circumstances such as prediabetes, low BMI and increased genetic risk of type 2 diabetes mellitus. This Review summarizes the possible causes and metabolic consequences of pancreatic fat accumulation. In addition, potential therapeutic approaches for addressing pancreatic fat accumulation are discussed.

Determining age and sex-specific distribution of pancreatic whole-gland CT attenuation using artificial intelligence aided image segmentation: Associations with body composition and pancreatic cancer risk

BACKGROUND & AIMS

Increased intrapancreatic fat is associated with pancreatic diseases; however, there are no established objective diagnostic criteria for fatty pancreas. On non-contrast computed tomography (CT), adipose tissue shows negative Hounsfield Unit (HU) attenuations (-150 to -30 HU). Using whole organ segmentation on non-contrast CT, we aimed to describe whole gland pancreatic attenuation and establish 5th and 10th percentile thresholds across a spectrum of age and sex. Subsequently, we aimed to evaluate the association between low pancreatic HU and risk of pancreatic ductal adenocarcinoma (PDAC).

METHODS

The whole pancreas was segmented in 19,456 images from 469 non-contrast CT scans. A convolutional neural network was trained to assist pancreas segmentation. Mean pancreatic HU, volume, and body composition metrics were calculated. The lower 5th and 10th percentile for mean pancreatic HU were identified, examining the association with age and sex. Pre-diagnostic CT scans from patients who later developed PDAC were compared to cancer-free controls.

RESULTS

Less than 5th percentile mean pancreatic HU was significantly associated with increase in BMI (OR 1.07; 1.03-1.11), visceral fat (OR 1.37; 1.15-1.64), total abdominal fat (OR 1.12; 1.03-1.22), and diabetes mellitus type 1 (OR 6.76; 1.68-27.28). Compared to controls, pre-diagnostic scans in PDAC cases had lower mean whole gland pancreatic HU (-0.2 vs 7.8, p = 0.026).

CONCLUSION

In this study, we report age and sex-specific distribution of pancreatic whole-gland CT attenuation. Compared to controls, mean whole gland pancreatic HU is significantly lower in the pre-diagnostic phase of PDAC.

Association of Incidence between Pancreatic Adipose Infiltration and Metabolic Syndrome: A Literature Review and Meta-analysis

Objective

To investigate association of incidence between pancreatic adipose infiltration and metabolic syndrome (METS).

Methods

We searched PubMed, Embase, Cochrane Library, and Web of Science databases up to July 2021. We compared incidence rate of METS between adults with and without pancreatic adipose infiltration, along with their clinical features, such as fasting blood glucose (FBG), triglyceride (TG), high-density lipoprotein (HDL), and hypertension (HTN). Cross-sectional study, cohort study, and case control study were included. Two investigators independently completed study selection, data extraction, and risk of bias assessment.

Results

Eleven eligible studies that involved 17,127 patients were included, including 8 cross-sectional studies, 2 cohort studies, and 1 case control study. There was a trend of increasing in incidence rate of METS (OR = 2.66, 95% CI: 1.89-3.75) of adults with pancreatic adipose infiltration when compared to those without the disease. There was a trend of increasing in HTN (OR = 1.68, 95% CI: 1.32-2.13) and levels of FBG (SMD = 0.54, 95% CI: 0.35-0.72) and TG (SMD = 0.39, 95% CI: 0.25-0.53) of adults with pancreatic adipose infiltration, while there was a trend of decreasing in HDL level (SMD = −0.29, 95% CI: -0.43~ -0.15).

Conclusion

There was an association of incidence between pancreatic adipose infiltration and METS. Indicators of clinical features related to pancreatic adipose infiltration were more likely to arise, such as FBG and TG levels and HTN, but HDL level tended to decrease.

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.

Pancreatic steatosis on computed tomography is an early imaging feature of pre-diagnostic pancreatic cancer: A preliminary study in overweight patients

BACKGROUND

The prevalence of pancreatic ductal adenocarcinoma (PDAC) is on the rise, driven by factors such as aging and an increasing prevalence of obesity and diabetes mellitus. To improve the poor survival rate of PDAC, early detection is vital. Recently, pancreatic steatosis has gained novel interest as a risk factor for PDAC. This study aimed to investigate if pancreatic steatosis on computed tomography (CT) is an early imaging feature in patients with pre-diagnostic PDAC.

METHODS

A retrospective case-control study was performed. Patients diagnosed with PDAC (2010-2016) were reviewed for abdominal non-contrast CT-imaging 1 month-3 years prior to their diagnosis. Cases were matched 1:4 with controls based on age, gender and imaging date. Unenhanced CT-images were evaluated for pancreatic steatosis (pancreas-to-spleen ratio in Hounsfield Units <0.70) by a blinded radiologist and results were compared between cases and controls.

RESULTS

In total, 32 cases and 117 controls were included in the study with a comparable BMI (29.6 and 29.2 respectively, p = 0.723). Pancreatic steatosis was present in 71.9% of cases compared to 45.3% of controls (Odds ratio (OR) 3.09(1.32-7.24), p = 0.009). Adjusted for BMI and diabetes mellitus, pancreatic steatosis on CT remained a significant independent risk factor for PDAC (Adjusted OR 2.70(1.14-6.58), p = 0.037).

CONCLUSION

Pancreatic steatosis measured on CT is independently associated with PDAC up to three years before the clinical diagnosis in overweight patients. If these data are confirmed, this novel imaging feature may be used to identify high-risk individuals and to stratify the risk of PDAC in individuals that already undergo PDAC screening.

Pathogenesis and remission of type 2 diabetes: what has the twin cycle hypothesis taught us?

Type 2 diabetes has been regarded a complex multifactorial disease that lead to serious health complications including high cardiovascular risks. The twin cycle hypothesis postulated that both hepatic insulin resistance and dysfunction rather than death of beta (β) cell determine diabetes onset. Several studies were carried out to test this hypothesis, and all demonstrated that chronic excess calorie intake and ectopic fat accumulation within the liver and pancreas are fundamental to the development of this disease. However, these recent research advances cannot determine the exact cause of this disease. In this review, the major factors that contribute to the pathogenesis and remission of type 2 diabetes will be outlined. Importantly, the effect of disordered lipid metabolism, characterized by altered hepatic triglyceride export will be discussed. Additionally, the observed changes in pancreas morphology in type 2 diabetes will be highlighted and discussed in relation to β cell function.

Decreased CT-number in the pancreatic parenchyma is a reliable imaging biomarker of the presence of malignancies in patients with high-risk intraductal papillary mucinous neoplasm

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is a premalignant cystic neoplasm of the pancreas and is frequently detected in imaging investigations. A proportion of the patients with IPMN develop malignancies including high-grade dysplasia and invasive carcinoma. To predict the presence of malignancies in IPMN, constant imaging follow-up is usually required. Pancreatic steatosis (PS) has been recently identified as a facilitating factor for pancreatic cancer, and can be predicted through computed tomography (CT). We hypothesized that the CT-number of the pancreatic parenchyma could be a new reliable imaging biomarker for IPMN patients.

METHODS

Eighty-six patients undergoing pancreatectomy for IPMN were investigated. Using preoperative CT, the pancreatic index (PI) was calculated by dividing the CT-number of the pancreas by that of the spleen.

RESULTS

Malignancies were pathologically detected in 63 cases (73.3%). Patients were divided into two cohorts according to the presence of malignancies and were compared for various factors including the PI scores. The comparison of the two cohorts detected significant differences in two parameters (CA19-9 and PI score), and the PI score was the most sensitive biomarker to predict the presence of malignancies in patients showing high-risk stigmata of IPMN.

CONCLUSIONS

Pancreatic CT-number is an additional reliable imaging biomarker in distinguishing patients with IPMN having malignancies when investigating the patients showing high-risk stigmata.

Preoperative Evaluation of Pancreatic Fibrosis and Lipomatosis: Correlation of Magnetic Resonance Findings With Histology Using Magnetization Transfer Imaging and Multigradient Echo Magnetic Resonance Imaging

OBJECTIVES

The purpose of this study was to evaluate the diagnostic performance of magnetization transfer (MT) imaging and multigradient echo magnetic resonance imaging (MRI) to quantify pancreatic fibrosis and lipomatosis in patients before pancreatoduodenectomy for postoperative risk stratification with histopathology as the reference standard.

MATERIALS AND METHODS

Twenty-four patients (age, 68 ± 8 years, 16 males) prospectively underwent quantitative MT imaging using a 2-dimensional gradient echo sequence with and without MT prepulse and multigradient echo imaging on a 3 T MRI 1 day before pancreatoduodenectomy due to adenocarcinoma of the pancreatic head region (n = 20), neuroendocrine tumor (n = 3), or intraductal papillary mucinous neoplasm (n = 1). Magnetization transfer ratio (MTR) and proton density fat fraction (PDFF) were measured in pancreatic tail (PT) and at the resection margin (RM). Histopathologically, pancreatic fibrosis was graded as mild, moderate, or severe (F1-F3), lipomatosis was graded as 0% to 10%, 11% to 30%, and greater than 30% fat deposition (L1-L3). In addition, MTR and histopathologic fibrosis was assessed in pancreatic adenocarcinoma. Mann-Whitney U test and Spearman correlation were used.

RESULTS

Patients with advanced pancreatic fibrosis (F3) showed a significantly higher MTR compared with the F1 group at the RM and PT (38 ± 4 vs 32.3 ± 1.6, P = 0.018 and 39.7 ± 5.5 vs 31.2 ± 1.7, P = 0.001). Spearman correlation coefficient of MTR and fibrosis grade was r = 0.532 (P = 0.011) and 0.554 (P = 0.008), respectively. Pancreatic parenchyma with advanced fat deposition (L2-L3) showed significantly higher PDFF compared with lipomatosis grade L1 (RM: P = 0.002 and PT: P = 0.001). Proton density fat fraction of pancreatic parenchyma exhibited a moderate and significant correlation with histopathologic lipomatosis grade (RM: r = 0.668 and PT: r = 0.707, P < 0.001). Magnetization transfer ratio was significantly higher in pancreatic adenocarcinoma compared with pancreatic parenchyma (44 ± 5.5 vs 36.0 ± 4.4 and 37.4 ± 5.4, P = 0.004).

CONCLUSIONS

Multiparametric MRI of the pancreas including MTR and PDFF maps may provide quantitative and noninvasive information on pancreatic fibrosis and lipomatosis before surgery.

The association between pancreas steatosis and metabolic syndrome: A systematic review and meta-analysis

OBJECTIVES

Pancreas steatosis is the description of fat accumulation in the pancreatic gland. The prevalence and development mechanisms of pancreatic steatosis in patients with metabolic disorders still remain unclear. The aim of this study is to systematically review the association between pancreatic steatosis and metabolic co-morbidities.

METHODS

We performed a systematic search strategy using three electronic databases (MEDLINE, Scopus, and Embase) for relevant studies concerning the associations of pancreatic steatosis with metabolic syndrome (MetS) and its clinical relevance from inception until 30 September 2018.

RESULTS

One thousand three hundred fifty one references were identified in the initial search, and a total of 13 studies involving 49 329 subjects were included. This analyses elucidated the presence of non-alcoholic fatty pancreas disease (NAFPD) and was associated with a significant increased risk of metabolic syndrome (RR = 2.25; 95% CI, 2.00-2.53; P < 0.0001; I²  = 42.8%; eight studies included), hypertension (RR = 1.43; 95% CI, 1.08-1.90; P = 0.013; I²  = 94.7%; nine studies included), non-alcoholic fatty liver disease (NAFLD) (RR = 2.49; 95% CI, 2.06-3.02; P < 0.0001; I²  = 96.9%; nine studies included), diabetes mellitus (RR = 1.99; 95% CI, 1.18-3.35; P = 0.01; I²  = 97.6%; 10 studies included), and central obesity (RR = 1.91; 95% CI, 1.67-2.19; P < 0.0001; I²  = 95.9%; six studies included). The association between NAFPD and hyperlipidaemia was not statistically significant (RR = 1.33; 95% CI, 0.82-2.17; P = 0.249; I²  = 97%; five studies included).

CONCLUSIONS

The existing evidence indicates that NAFPD is significantly associated with an increased risk of metabolic syndrome and its components. Well-designed prospective cohort studies between pancreatic steatosis and MetS are needed to elaborate the causality in the future.

Evaluation of fatty pancreas by proton density fat fraction using 3-T magnetic resonance imaging and its association with pancreatic cancer

PURPOSE

To evaluate whether pancreatic magnetic resonance imaging-proton density fat fraction (MRI-PDFF) correlates with histological pancreatic fat fraction and its possible usefulness as a biomarker of pancreatic cancer compared with pancreatic index (PI) using computed tomography (CT number of the pancreas divided by that of the spleen).

METHOD

We included 55 consecutive patients (24 with pancreatic cancer and 31 controls; median age, 72 years) who preoperatively underwent MRI-PDFF using IDEAL-IQ and unenhanced CT and did not receive preoperative therapy. Histologic pancreatic fat fraction was measured in non-tumorous pancreatic tissues at the resection stump. A board-certified radiologist evaluated MRI-PDFF and PI. Correlations were evaluated among MRI-PDFF, PI, and histologic pancreatic fat fraction; the usefulness of MRI-PDFF as a predictor of pancreatic cancer was assessed.

RESULTS

Histologic pancreatic fat fraction significantly correlated with MRI-PDFF and PI (r = 0.802 and -0.534, respectively; P < 0.01). The absolute correlation coefficient was significantly higher for MRI-PDFF than for PI (P < 0.01). Compared with the control group, the pancreatic cancer group had higher MRI-PDFF and histologic pancreatic fat fraction (P < 0.01) but lower PI (P < 0.01). In multivariate analysis, MRI-PDFF was found to be the sole independent risk factor for pancreatic cancer (odds ratio: 1.19; P < 0.01).

CONCLUSIONS

Pancreatic fat, which was associated with pancreatic cancer, could be quantified by MRI-PDFF measurement; therefore, MRI-PDFF should be considered as a promising and superior imaging biomarker for estimating the probability of pancreatic cancer than PI.

Comparison of Duodenal Mucosal Chromogranin-A Expression in Non-Alcoholic Fatty Pancreas Dyspeptic Patients with and without Endosonography-Diagnosed Early Chronic Pancreatitis: A Case Series Study

Nonalcoholic fatty pancreas (NAFP) is hypothetically related to progressive fibro-inflammation of the pancreas whose exocrine function is controlled by enteroendocrine cells (EEC). There is little evidence of pancreatic fibrosis in fatty pancreas and of whether there are quantitative differences for EEC. This study aimed to prove the coexistence of NAFP and pancreatic fibrosis or early chronic pancreatitis (ECP) using acoustic radiation force impulse (ARFI) and endosonography. Besides, the expression of duodenal mucosal chromogranin-A, a surrogate for EEC, was analyzed. Dyspeptic patients were surveyed at the digestive clinic and received abdominal sonography, endosonography, and serology tests. Cases with organic causes of dyspepsia were excluded. Pancreatic fibrosis was defined as an ARFI value ≥1.3 m/s. ECP was defined by at least 2 scores of the Japan Pancreas Society endosonographic criteria. During endosonography, 4 biopsy samples of mucosa in the duodenal first part were obtained for analysis of chromogranin-A expression by Western blot. Mucosal biopsy was also performed at the gastric antrum for surveillance of Helicobacter pylori. Between January and June 2018, a total of 24 patients with NAFP were enrolled among 48 candidates and divided into 2 groups based on whether they had pancreatic fibrosis or not. In the pancreatic fibrosis group (n = 11, pancreatic ARFI: 1.76 ± 0.34 m/s), there was a higher endosonographic criteria score (2.45 vs. 1.61, p = 0.002), increased expression of chromogranin-A (p = 0.001), and more severe fatty pancreas that was defined by pancreatic duct blurring on abdominal sonography (91 vs. 46%, p = 0.062) as compared to the non-pancreatic fibrosis group (n = 13, pancreatic ARFI: 1.11 ± 0.09 m/s). A total of 54 endosonographic abnormalities of ECP was present in these 24 patients in the head (52%), body (31%), and tail (17%), an anatomic pattern similar to pancreatic adenocarcinoma. In conclusion, among dyspeptic patients with NAFP, the duodenal mucosa chromogranin-A showed increased expression in those with pancreatic fibrosis and endosonography-diagnosed ECP.

MRI assessment of ectopic fat accumulation in pancreas, liver and skeletal muscle in patients with obesity, overweight and normal BMI in correlation with the presence of central obesity and metabolic syndrome

Purpose: Obesity, defined as a body mass index (BMI) exceeding 30 kg/m², is a serious health problem, which can be called an epidemic on a global scale and is one of the most important causes of preventable death. The aim of this study was to assess ectopic fat accumulation in pancreas, liver and skeletal muscle in patients with obesity, overweight and normal BMI in correlation with metabolic syndrome (MetS). Patients and methods: The study included 267 consecutive patients who underwent a standard clinical assessment with BMI calculation. Ectopic fat accumulation in pancreas, liver, and skeletal muscle was evaluated by magnetic resonance imaging (MRI) using fat-water separated Dixon imaging. MetS was defined according to the criteria modified by the National Cholesterol Education Program Adult Treatment Panel III Guidelines. Central obesity was defined using gender and ethnic-specific values for waist circumference. Results: There was a statistically significant correlation between the degree of steatosis of the assessed organs and BMI value as well as waist circumference ratio, that determined the degree of central obesity. It was found that the most rapid relative fat accumulation was in muscle, then in pancreas and then in liver. Higher steatosis of pancreas, liver, and muscle was demonstrated depending on the number of the satisfied MetS criteria. Conclusion: Knowing that pancreatic fatty disease is a risk factor for MetS, it seems that assessment and monitoring of ectopic fat accumulation may have important clinical implications and may be used in the prediction of metabolic risk and its early prevention.

Pancreatic Cancer and Obesity: Molecular Mechanisms of Cell Transformation and Chemoresistance

Cancer and obesity are the two major epidemics of the 21st century. Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of death, with a five-year overall survival rate of only 8%. Its incidence and mortality have increased in recent years, and this cancer type is expected to be among the top five leading causes of cancer-related death by 2030 in the United States (US). In the last three decades, the prevalence of overweight people has boosted with a consequent increase in obesity-related diseases. Considerable epidemiologic evidence correlates overweight and obese conditions to an increased risk of several types of cancer, including PDAC. Besides being a risk factor for multiple metabolic disorders, the tumor-promoting effects of obesity occur at the local level via inflammatory mediators that are associated with adipose inflammation and metabolic or hormones mediators and microbiota dysbiosis. Although an excess of body mass index (BMI) represents the second most modifiable risk factor for PDAC with an increased cancer related-death of more than 20–40%, still little is known about the molecular mechanisms that underlie this strong association. In this review, we focused on the role of obesity as a preventable risk factor of PDAC, discussing the molecular mechanisms linking obesity to cancer initiation and progression. Moreover, we highlighted the role of obesity in defining chemoresistance, showing how a high BMI can actually reduce response to chemotherapy.

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.

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.

Adipose Tissue-Secreted Factors Alter Bladder Cancer Cell Migration

BACKGROUND

Obesity is associated with an increased risk of bladder cancer recurrence. This study investigated the role of adipose tissue in bladder cancer progression.

METHODS

Gene expression profiling was performed on adipose tissues collected from normal weight (n=5), overweight (n=11), and obese (n=10) patients with invasive bladder cancer, and adipose stromal cells (ASCs) were obtained from two normal weight, two overweight, and two obese patients. Conditioned media (CM) was characterized and evaluated for its effects on the proliferation, migration, and invasive potential of T24 bladder cancer cells.

RESULTS

Expression profiling demonstrated depot-specific or body mass index-specific differences. Increased T24 cell migration was observed using CM harvested from all ASCs. ASC CM from an obese patient significantly increased T24 cell migration and invasion compared to ASC CM collected from normal weight and overweight patients. We identified abundant expression of CXCL1, PAI1, IL6, CX3CL1, and CCL2 in all CM. Exogenous treatment of T24 cells with PAI1, IL6, and CXCL1 enhanced migration. Depletion of CXCL1, PAI1, and IL6 in an obese patient ASC CM abrogated T24 migration.

CONCLUSION

Factors secreted by adipose tissue influence the migration of bladder tumor cells and could play an active role in tumor progression.

Suppression of Gingival NK Cells in Precancerous and Cancerous Stages of Pancreatic Cancer in KC and BLT-Humanized Mice

The aim of our studies is to determine the dynamics of natural killer (NK) cell modulation in gingivae in precancerous and cancerous stages of pancreatic and oral cancers in P48+/Cre;LSL-KRASG12D (KC) mice carrying a pancreas-specific oncogenic Kras mutation and BLT-humanized mice. Wild type and KC mice fed with control diet (CD) or high-fat calorie diet (HFCD), and the pancreatic and oral tumor-bearing humanized BLT (hu-BLT) mice were used to determine precancerous and cancer induced changes in numbers and function of gingival NK cells. Increased numbers of PanIN lesions and the greatest score of inflammation in pancreas of KC mice fed with CD and HFCD co-related with significant decline in percentages of circulating and gingival NK cells, lack of DX5+ NK expansion and increased secretion of IFN-γ and IL-6 after culture. At the malignant stage of pancreatic cancer, hu-BLT tumor-bearing mice had the lowest secretion of IFN-γ from cells dissociated from the gingival tissues as compared to those from non-tumor-bearing mice. Injection of NK cells into tumor-bearing mice increased IFN-γ secretion, and the secretion was similar or higher than those obtained by gingival cells from non-tumor-bearing hu-BLT control mice. The highest increase in IFN-γ secretion was observed when tumor-bearing mice were fed with AJ2 probiotic bacteria and injected with the NK cells. Along with an increase in secretion of IFN-γ, injection of NK cells in the presence and absence of feeding with AJ2 in pancreatic tumor-bearing mice increased percentages of CD45+ and CD3+ T cells in oral gingival cells. Similar results were observed with oral tumors. In conclusion, these results indicated that oral cavity may mirror systemic disease and provide a rationale for why cancer patients may be prone to suffer from diverse oral pathologies.

Transabdominal ultrasonography of the pancreas is superior to that of the liver for detection of ectopic fat deposits resulting from metabolic syndrome

The aim of our study was to investigate the rate of nonalcoholic fatty pancreas disease (NAFPD) in the south China province of Fujian and its relationship to nonalcoholic fatty liver disease (NAFLD) and metabolic parameters.NAFPD is frequently identified on transabdominal ultrasound examination. The incidence of NAFPD varies from 16% to 69.7% depending on the country.A total of 256 subjects were recruited. Each was assessed by abdominal sonography to diagnose NAFLD and NAFPD. The ages, sexes, heights, weights, blood pressure, and detection of peripheral blood biochemical indices (cholesterol, triglycerides, high-density lipoprotein cholesterol [HDL], low-density lipoprotein cholesterol [LDL], and glucose) were recorded. The relationships among metabolic parameters and NAFPD or NAFLD were evaluated, and the positive rates of NAFLD and NAFPD in the general population were compared.The age, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), cholesterol, triglycerides, HDL, LDL, and glucose were significantly associated with NAFPD and NAFLD but the positive rate of NAFPD was significantly higher than that of NAFLD. The BMI, age, and NAFLD were the independent risk factors of NAFPD. The sex distribution, weight, SBP, DBP, BMI, LDL, HDL, triglycerides, glucose, cholesterol, NAFPD, and NAFLD were different significantly between metabolic syndrome and normal subjects.NAFPD and NAFLD can reflect the body metabolism, but NAFPD has a higher detection rate.

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.

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.

The emerging roles of F-box proteins in pancreatic tumorigenesis

The role of F-box proteins in pancreatic tumorigenesis is emerging owing to their pivotal and indispensable roles in cell differentiation, cell cycle regulation and proliferation. In this review, we will focus on β-TrCP (β-transducin repeat-containing protein) and two other prototypical mammalian F-box proteins, Fbxw7 and Fbxw8, in pancreatic tumorigenesis and progression. We will highlight the functions and regulation of these F-box proteins, their respective substrates and cross-talks with other key signaling pathways, such as the Ras-Raf-Mek-Erk, Hedgehog, NFκB, TGF-β, Myc and HPK1 signaling pathways in pancreatic cancer.