Diabetes mellitus, glycated haemoglobin and C-peptide levels in relation to pancreatic cancer risk: a study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Trend and forecast analysis of the changing disease burden of pancreatic cancer attributable to high fasting glucose in China, 1990-2021

Background

Pancreatic cancer (PC) is a malignant tumour with poor prognosis and high mortality, and high fasting plasma glucose (HFPG) is considered to be one of its important risk factors.

Methods

PC disease burden data were obtained from the Global Burden of Disease Study 2021 (GBD 2021) database. Annual percent change (APC), average APC (AAPC), and 95% confidence interval (95% CI) were analysed using joinpoint linkpoint regression models to assess the trend of PC burden of disease between 1990 and 2021. An age-period-cohort model was used to estimate the independent effects of age, period, and cohort on PC burden, and data on PC mortality attributable to HFPG in China from 2022 to 2032 were analysed on the basis of a Bayesian age-period-cohort model projection.

Results

The number of Pc deaths due to HFPG continue to rise in China from 1990 to 2021, with age-standardised mortality (ASMR) and age-standardised disability-adjusted life-year rates with increasing AAPC values of 1.12% (95% CI, 0.73-1.52) and 1.00% (95% CI, 0.63-1.37), respectively. Throughout the study, we found that the overall level of PC disease burden was significantly higher in men than that in women. In age-period-cohort analyses, the age effect of PC showed an increasing and then decreasing trend, the period effect showed an overall increasing trend during the study period, and the cohort effect showed an overall slow decreasing trend. In addition, the BAPC model predicted that ASMR is expected to decline significantly in both men and women from 2022 to 2032.

Conclusions

It was found that PC attributable to HFPG was generally on the rise in China from 1990 to 2021 and has been on the decline in recent years, and projections suggest that the country's future PC disease burden will continue to show a downward trend. Age and period of birth are the main factors affecting the disease burden, especially in men and older age groups. Early prevention, regular screening, and research into the pathogenesis of PC have, therefore, become particularly important.

Prediabetes increases the risk of pancreatic cancer: A meta-analysis of longitudinal observational studies

BACKGROUND

Glycemic disorder is closely related to the risk of pancreatic cancer, but previous studies focused on the influence of diabetes. The aim of this meta-analysis was to investigate the influence of prediabetes, an intermediate state between normoglycemia and diabetes, on the risk of pancreatic cancer.

METHODS

Relevant longitudinal observational studies were identified through a search of Medline, Embase, and Web of Science databases. To minimize the influence of between-study heterogeneity, a randomized-effects model was used to pool the results.

RESULTS

Nine cohort studies including 26,444,624 subjects were available for the meta-analysis. Among them, 2,052,986 (7.8%) had prediabetes at baseline, and the participants were followed for a mean duration of 5.9 years. It was found that, compared to people with normoglycemia, those with prediabetes had a higher incidence of pancreatic cancer (risk ratio [RR]: 1.42, 95% confidence interval: 1.36 to 1.49, p<0.001) with no statistical heterogeneity (I2 = 0%). Sensitivity analysis performed by excluding one dataset at a time did not significantly change the results (RR: 1.38 to 1.45, p all <0.05). Subgroup analyses indicated that the association between prediabetes and increased risk of pancreatic cancer was not significantly impacted by study characteristics such as study design, location, age, and sex of participants, definition of prediabetes, duration of follow-up, or adjustment for alcohol intake (p for subgroup difference all >0.05).

CONCLUSIONS

Prediabetes may be associated with an increased risk of pancreatic cancer compared to normoglycemia.

Preoperative Glycosylated Hemoglobin A1C Impacts Long-Term Outcomes Following Curative-Intent Resection of Nonfunctional Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

To investigate the impact of preoperative glycosylated hemoglobin A1C (HbA1c) among patients following curative-intent resection of nonfunctional gastroentropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

Patients who underwent curative-intent resection for GEP-NETs from 2000 to 2020 were identified from the US Neuroendocrine Tumor Study Group (US-NETSG). Preoperative blood HbA1c levels were defined as high HbA1c (≥ 6.5%) versus low HbA1c group (< 6.5%). Impact of HbA1c level on postoperative short-term and long-term overall (OS) were investigated.

RESULTS

A total of 130 patients with HbA1c < 6.5% and 60 patients with HbA1c ≥ 6.5% were included. Patients with HbA1c ≥ 6.5% had higher proportion of comorbidities, such as hypertension, obesity, anemia, and lower preoperative albumin levels versus patients with HbA1c < 6.5% (all p < 0.05). In addition, high level of preoperative HbA1c was associated with increased incidence of wound and infectious complications, as well as decreased long-term OS (median OS: high Hb1Ac 89.8 months vs. low Hb1Ac not reached, HR 3.487, p = 0.004) among patients with nonfunctional GEP-NETs, as well as among the subset of pancreatic NET patients (median OS: high Hb1Ac 74.3 months vs. low Hb1Ac not reached, p = 0.004), and patients with normal fasting blood glucose (< 140 mg/dL) (median OS: high Hb1Ac 75.4 months vs. low Hb1Ac not reached, p = 0.001).

CONCLUSIONS

Hb1Ac might have value as a screening tool to identify high-risk patients following surgical resection of nonfunctional GEP-NETs for consideration of more strict postoperative surveillance and treatment of elevated Hb1Ac level.

Elevated Glycated Haemoglobin (HbA1c) Is Associated with an Increased Risk of Pancreatic Ductal Adenocarcinoma: A UK Biobank Cohort Study

BACKGROUND

The role of dysglycaemia as a risk marker for Pancreatic Ductal Adenocarcinoma (PDAC) is uncertain. We investigated the relationship between glycated haemoglobin (HbA1c) and incident PDAC using a retrospective cohort study within the UK Biobank.

METHODS

A study involving 499,804 participants from the UK Biobank study was undertaken. Participants were stratified by diabetes mellitus (DM) status, and then by HbA1c values < 42 mmol/mol, 42-47 mmol/mol, or ≥48 mmol/mol. Cox proportional hazard models were used to describe the association between HbA1c category (with time-varying interactions) and incident PDAC.

RESULTS

PDAC occurred in 1157 participants during 11.6 (10.9-12.3) years follow up [(median (interquartile range)]. In subjects without known DM at baseline, 12 months after recruitment, the adjusted hazard ratios (aHR, 95% CI) for incident PDAC for HbA1c 42-47 mmol/mol compared to HbA1c < 42 mmol/mol (reference group) was 2.10 (1.31-3.37, p = 0.002); and was 8.55 (4.58-15.99, p < 0.001) for HbA1c ≥ 48 mmol/mol. The association between baseline HbA1c and incident PDAC attenuated with increasing duration of time of follow-up to PDAC diagnosis.

CONCLUSIONS

Dysglycaemia detected by elevated HbA1c is associated with an increased risk of PDAC. The strength of the association between elevated HbA1c and incident PDAC is inversely proportional to the time from detecting dysglycaemia but remains significant for at least 60 months following HbA1c testing.

Is Diabetes Mellitus a Predisposing Factor for Helicobacter pylori Infections?

PURPOSE OF REVIEW

This review aims to analyse the consistency of reports suggesting the role of Diabetes Mellitus in the pathogenesis of Helicobacter pylori (H. pylori).

RECENT FINDINGS

There have been numerous controversies citing the prevalence of H. pylori infections in patients suffering from type 2 diabetes mellitus (T2DM). This review investigates the possible crosstalk between H. pylori infections and T2DM and also designs a meta-analysis to quantify the association. Subgroup analyses have also been conducted to deduce factors like geography and testing techniques, in playing a role in stratification analysis. Based on a scientific literature survey and meta-analysis of databases from 1996 to 2022, a trend towards more frequent H. pylori infections in patients with diabetes mellitus was observed. The highly diversified nature of H. pylori infections across age, gender, and geographical regions requires large interventional studies to evaluate its long-term association with diabetes mellitus. Further possible linkage of the prevalence of diabetes mellitus concomitant with that of H. pylori infected patients has also been delineated in the review.

Diagnostic and prognostic role of circRNAs in pancreatic cancer: a meta-analysis

Background

Circular RNAs (circRNAs) are types of endogenous noncoding RNAs produced by selective splicing that are expressed highly specifically in various organisms and tissues and have numerous clinical implications in the regulation of cancer development and progression. Since circRNA is resistant to digestion by ribonucleases and has a long half-life, there is increasing evidence that circRNA can be used as an ideal candidate biomarker for the early diagnosis and prognosis of tumors. In this study, we aimed to reveal the diagnostic and prognostic value of circRNA in human pancreatic cancer (PC).

Methods

A systematic search for publications from inception to 22 July 2022 was conducted on Embase, PubMed, Web of Science (WOS), and the Cochrane Library databases. Available studies that correlated circRNA expression in tissue or serum with the clinicopathological, diagnostic, and prognostic values of PC patients were enrolled. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to evaluate clinical pathological characteristics. Area under the curve (AUC), sensitivity, and specificity were adopted to assess diagnostic value. Hazard ratios (HRs) were utilized to assess disease-free survival (DFS) and overall survival (OS).

Results

This meta-analysis enrolled 32 eligible studies, including six on diagnosis and 21 on prognosis, which accounted for 2,396 cases from 245 references. For clinical parameters, high expression of carcinogenic circRNA was significantly associated with degree of differentiation (OR = 1.85, 95% CI = 1.47-2.34), TNM stage (OR = 0.46, 95% CI = 0.35-0.62), lymph node metastasis (OR = 0.39, 95% CI = 0.32-0.48), and distant metastasis (OR = 0.26, 95% CI = 0.13-0.51). As for clinical diagnostic utility, circRNA could discriminate patients with pancreatic cancer from controls, with an AUC of 0.86 (95% CI: 0.82-0.88), a relatively high sensitivity of 84%, and a specificity of 80% in tissue. In terms of prognostic significance, carcinogenic circRNA was correlated with poor OS (HR = 2.00, 95% CI: 1.76-2.26) and DFS (HR = 1.96, 95% CI: 1.47-2.62).

Conclusion

In summary, this study demonstrated that circRNA may act as a significant diagnostic and prognostic biomarker for pancreatic cancer.

Nutraceuticals as Supportive Therapeutic Agents in Diabetes and Pancreatic Ductal Adenocarcinoma: A Systematic Review

The correlation between pancreatic ductal adenocarcinoma (PDAC) and diabetes-related mechanisms support the hypothesis that early therapeutic strategies targeting diabetes can contribute to PDAC risk reduction and treatment improvement. A systematic review was conducted, using PubMed, Embase and Cochrane Library databases, to evaluate the current evidence from clinical studies qualitatively examining the efficacy of four natural products: Curcumin-Curcuma longa L.; Thymoquinone-Nigella sativa L.; Genistein-Glycine max L.; Ginkgo biloba L.; and a low-carbohydrate ketogenic diet in type 2 diabetes (T2D) and PDAC treatment. A total of 28 clinical studies were included, showing strong evidence of inter-study heterogeneity. Used as a monotherapy or in combination with chemo-radiotherapy, the studied substances did not significantly improve the treatment response of PDAC patients. However, pronounced therapeutic efficacy was confirmed in T2D. The natural products and low-carbohydrate ketogenic diet, combined with the standard drugs, have the potential to improve T2D treatment and thus potentially reduce the risk of cancer development and improve multiple biological parameters in PDAC patients.

Proteogenomic insights into the biology and treatment of pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with poor prognosis. Proteogenomic characterization and integrative proteomic analysis provide a functional context to annotate genomic abnormalities with prognostic value.

METHODS

We performed an integrated multi-omics analysis, including whole-exome sequencing, RNA-seq, proteomic, and phosphoproteomic analysis of 217 PDAC tumors with paired non-tumor adjacent tissues. In vivo functional experiments were performed to further illustrate the biological events related to PDAC tumorigenesis and progression.

RESULTS

A comprehensive proteogenomic landscape revealed that TP53 mutations upregulated the CDK4-mediated cell proliferation process and led to poor prognosis in younger patients. Integrative multi-omics analysis illustrated the proteomic and phosphoproteomic alteration led by genomic alterations such as KRAS mutations and ADAM9 amplification of PDAC tumorigenesis. Proteogenomic analysis combined with in vivo experiments revealed that the higher amplification frequency of ADAM9 (8p11.22) could drive PDAC metastasis, though downregulating adhesion junction and upregulating WNT signaling pathway. Proteome-based stratification of PDAC revealed three subtypes (S-I, S-II, and S-III) related to different clinical and molecular features. Immune clustering defined a metabolic tumor subset that harbored FH amplicons led to better prognosis. Functional experiments revealed the role of FH in altering tumor glycolysis and in impacting PDAC tumor microenvironments. Experiments utilizing both in vivo and in vitro assay proved that loss of HOGA1 promoted the tumor growth via activating LARP7-CDK1 pathway.

CONCLUSIONS

This proteogenomic dataset provided a valuable resource for researchers and clinicians seeking for better understanding and treatment of PDAC.

The Development of a Prediction Model Based on Random Survival Forest for the Postoperative Prognosis of Pancreatic Cancer: A SEER-Based Study

Simple Summary

Surgery is the main treatment to cure pancreatic cancer (PC). However, the 5-year survival rate of surgical resection is only 10–20%. The aim of our study was to develop a prediction model with the novel machine learning algorithm random survival forest (RSF) and to offer easy-to-use prediction tools, including risk stratification and individual prognosis. The study would benefit patients and physicians in postoperative management and facilitate personalized medicine.

Abstract

Accurate prediction for the prognosis of patients with pancreatic cancer (PC) is a emerge task nowadays. We aimed to develop survival models for postoperative PC patients, based on a novel algorithm, random survival forest (RSF), traditional Cox regression and neural networks (Deepsurv), using the Surveillance, Epidemiology, and End Results Program (SEER) database. A total of 3988 patients were included in this study. Eight clinicopathological features were selected using least absolute shrinkage and selection operator (LASSO) regression analysis and were utilized to develop the RSF model. The model was evaluated based on three dimensions: discrimination, calibration, and clinical benefit. It found that the RSF model predicted the cancer-specific survival (CSS) of the postoperative PC patients with a c-index of 0.723, which was higher than the models built by Cox regression (0.670) and Deepsurv (0.700). The Brier scores at 1, 3, and 5 years (0.188, 0.177, and 0.131) of the RSF model demonstrated the model’s favorable calibration and the decision curve analysis illustrated the model’s value of clinical implement. Moreover, the roles of the key variables were visualized in the Shapley Additive Explanations plotting. Lastly, the prediction model demonstrates value in risk stratification and individual prognosis. In this study, a high-performance prediction model for PC postoperative prognosis was developed, based on RSF The model presented significant strengths in the risk stratification and individual prognosis prediction.

Prospective associations of hemoglobin A1c and c-peptide with risk of diabetes-related cancers in the Cancer Prevention Study-II Nutrition Cohort

Self-reported type 2 diabetes mellitus (T2DM) is a risk factor for many cancers, suggesting its pathology relates to carcinogenesis. We conducted a case-cohort study to examine associations of hemoglobin A1c (HbA1c) and c-peptide with cancers associated with self-reported T2DM. This study was drawn from a prospective cohort of 32,383 women and men who provided blood specimens at baseline: c-peptide and HbA1c were assessed in 3,000 randomly selected participants who were cancer-free-at-baseline and an additional 2,281 participants who were cancer-free-at-baseline and subsequently diagnosed with incident colorectal, liver, pancreatic, female breast, endometrial, ovarian, bladder, or kidney cancers. Weighted-Cox regression models estimated hazards ratios (HRs) and 95% confidence intervals (CI), adjusted for covariates. C-peptide was associated with higher risk of liver cancer (per standard deviation (SD) HR: 1.80; 95%CI: 1.32-2.46). HbA1c was associated with higher risk of pancreatic cancer (per SD HR: 1.21 95%CI 1.05-1.40) and with some suggestion of higher risks for all-cancers-of-interest (per SD HR: 1.05; 95%CI: 0.99-1.11) and colorectal (per SD HR: 1.09; 95%CI: 0.98-1.20), ovarian (per SD HR: 1.18; 95%CI 0.96-1.45) and bladder (per SD HR: 1.08; 95%CI 0.96-1.21) cancers. Compared to no self-reported T2DM and HbA1c <6.5% (reference group), self-reported T2DM and HbA1c <6.5% (i.e., T2DM in good glycemic control) was not associated with risk of colorectal cancer, whereas it was associated with higher risks of all-cancers-of-interest combined (HR: 1.28; 95%CI: 1.01-1.62), especially for breast and endometrial cancers. Additional large, prospective studies are needed to further explore the roles of hyperglycemia, hyperinsulinemia, and related metabolic traits with T2DM-associated cancers to better understand the mechanisms underlying the self-reported T2DM-cancer association and to identify persons at higher cancer risk.

The Role of Circulating Protein and Metabolite Biomarkers in the Development of Pancreatic Ductal Adenocarcinoma (PDAC): A Systematic Review and Meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, and this is attributed to it being diagnosed at an advanced stage. Understanding the pathways involved in initial development may improve early detection strategies. This systematic review assessed the association between circulating protein and metabolite biomarkers and PDAC development.

METHODS

A literature search until August 2020 in MEDLINE, EMBASE, and Web of Science was performed. Studies were included if they assessed circulating blood, urine, or salivary biomarkers and their association with PDAC risk. Quality was assessed using the Newcastle-Ottawa scale for cohort studies. Random-effects meta-analyses were used to calculate pooled relative risk.

RESULTS

A total of 65 studies were included. Higher levels of glucose were found to be positively associated with risk of developing PDAC [n = 4 studies; pooled relative risk (RR): 1.61; 95% CI: 1.16-2.22]. Additionally, an inverse association was seen with pyridoxal 5'-phosphate (PLP) levels (n = 4 studies; RR: 0.62; 95% CI: 0.44-0.87). Meta-analyses showed no association between levels of C-peptide, members of the insulin growth factor signaling pathway, C-reactive protein, adiponectin, 25-hydroxyvitamin D, and folate/homocysteine and PDAC risk. Four individual studies also reported a suggestive positive association of branched-chain amino acids with PDAC risk, but due to differences in measures reported, a meta-analysis could not be performed.

CONCLUSIONS

Our pooled analysis demonstrates that higher serum glucose levels and lower levels of PLP are associated with risk of PDAC.

IMPACT

Glucose and PLP levels are associated with PDAC risk. More prospective studies are required to identify biomarkers for early detection.

Comparison of New Glucose-Lowering Drugs on Risk of Pancreatitis in Type 2 Diabetes: A Network Meta-Analysis

BACKGROUND & AIMS

Whether new glucose-lowering drugs increases the risk of pancreatitis in individuals with type 2 diabetes remains controversial. This present network meta-analysis aims to investigate the risk of pancreatitis associated with the use of glucagon-like peptide (GLP)-1 agonists and dipeptidyl peptidase (DPP)-4 inhibitors in the treatment of type 2 diabetes mellitus.

METHODS

PubMed, Web of Science, EMBASE and the Cochrane Library were searched. The literature was published from the date of their inception to July 21, 2021, including placebo-controlled or head-to-head trials of 2 new glucose-lowering drugs. Relative ratio (RR) and 95% confidence interval (CI) were used to assess the risk of GLP-1 agonists and DPP-4 inhibitors for pancreatitis or pancreatic cancer among patients with type 2 diabetes.

RESULTS

Seventeen studies were identified, covered 102257 participants. The pooled results showed a neutral relationship between GLP-1 agonists and pancreatitis (Overall RR, 0.96; 95% CI, 0.31-3.00) or pancreatic cancer (Overall RR, 1.10; 95% CI, 0.31-4.10) compared to placebo. Meanwhile, DPP-4 inhibitors were not be associated with the increased risk of pancreatitis (Overall RR, 1.60; 95% CI, 0.25-11.00) or pancreatic cancer (Overall RR, 0.79; 95% CI, 0.26-2.40). Among them, lixisenatide and saxagliptin may be the safest drug compared to other drugs according to the ranking of probability. Sensitivity and subgroup analysis confirmed the stability of the core results.

CONCLUSION

The most obvious finding to emerge from this study is that GLP-1 agonists and DPP-4 inhibitors are safe with respect to pancreatitis and pancreatic cancer risk compared to placebo. This conclusion may provide useful evidence for correlated clinical researches.

NF-κB and Pancreatic Cancer; Chapter and Verse

Pancreatic Ductal Adenocarcinoma (PDAC) is one of the world's most lethal cancers. An increase in occurrence, coupled with, presently limited treatment options, necessitates the pursuit of new therapeutic approaches. Many human cancers, including PDAC are initiated by unresolved inflammation. The transcription factor NF-κB coordinates many signals that drive cellular activation and proliferation during immunity but also those involved in inflammation and autophagy which may instigate tumorigenesis. It is not surprising therefore, that activation of canonical and non-canonical NF-κB pathways is increasingly recognized as an important driver of pancreatic injury, progression to tumorigenesis and drug resistance. Paradoxically, NF-κB dysregulation has also been shown to inhibit pancreatic inflammation and pancreatic cancer, depending on the context. A pro-oncogenic or pro-suppressive role for individual components of the NF-κB pathway appears to be cell type, microenvironment and even stage dependent. This review provides an outline of NF-κB signaling, focusing on the role of the various NF-κB family members in the evolving inflammatory PDAC microenvironment. Finally, we discuss pharmacological control of NF-κB to curb inflammation, focussing on novel anti-cancer agents which reinstate the process of cancer cell death, the Smac mimetics and their pre-clinical and early clinical trials.

Type 2 Diabetes Mellitus Intersects With Pancreatic Cancer Diagnosis and Development

The relationship between type 2 diabetes mellitus (T2DM) and pancreatic cancer (PC) is complex. Diabetes is a known risk factor for PC, and new-onset diabetes (NOD) could be an early manifestation of PC that may be facilitate the early diagnosis of PC. Metformin offers a clear benefit of inhibiting PC, whereas insulin therapy may increase the risk of PC development. No evidence has shown that novel hypoglycemic drugs help or prevent PC. In this review, the effects of T2DM on PC development are summarized, and novel strategies for the prevention and treatment of T2DM and PC are discussed.

[Early detection of pancreatic cancer - The role of endoscopic and transabdominal ultrasound]

Pancreatic neoplasms are less common tumors and have a poor prognosis when advanced. Early diagnosis would be beneficial for survival, but screening of the whole population cannot be justified with a satisfying benefit-effort correlation. Subgroups of patients with a higher than average risk are those with germ-like mutations, familial cancers risks, and mucinous cystadenomas that would benefit from surveillance programs. Other risk groups, like patients with pancreatitis, new onset diabetes, and heavy smokers, should be considered as well. Transabdominal ultrasonography is of great advantage as a first-line imaging method because of its easy access. The accuracy for adenocarcinoma diagnosis is nearly 90% while using CEUS. Endosonography is of extraordinary importance in the diagnostic approach of pancreatic tumors because of high sensitivity and specificity while using advanced imaging techniques like CEUS, elastography, and fine needle biopsy. Screening by means of EUS is also possible in high-risk situations, and a favourable cost-benefit ratio must be shown by future data.

Pancreatic cancer epidemiology: understanding the role of lifestyle and inherited risk factors

Pancreatic cancer is a leading cause of cancer death worldwide and its global burden has more than doubled over the past 25 years. The highest incidence regions for pancreatic cancer include North America, Europe and Australia, and although much of this increase is due to ageing worldwide populations, there are key modifiable risk factors for pancreatic cancer such as cigarette smoking, obesity, diabetes and alcohol intake. The prevalence of these risk factors is increasing in many global regions, resulting in increasing age-adjusted incidence rates for pancreatic cancer, but the relative contribution from these risk factors varies globally due to variation in the underlying prevalence and prevention strategies. Inherited genetic factors, although not directly modifiable, are an important component of pancreatic cancer risk, and include pathogenic variants in hereditary cancer genes, genes associated with hereditary pancreatitis, as well as common variants identified in genome-wide association studies. Identification of the genetic changes that underlie pancreatic cancer not only provides insight into the aetiology of this cancer but also provides an opportunity to guide early detection strategies. The goal of this Review is to provide an up-to-date overview of the established modifiable and inherited risk factors for pancreatic cancer.

Deciphering the complex interplay between pancreatic cancer, diabetes mellitus subtypes and obesity/BMI through causal inference and mediation analyses

OBJECTIVES

To characterise the association between type 2 diabetes mellitus (T2DM) subtypes (new-onset T2DM (NODM) or long-standing T2DM (LSDM)) and pancreatic cancer (PC) risk, to explore the direction of causation through Mendelian randomisation (MR) analysis and to assess the mediation role of body mass index (BMI).

DESIGN

Information about T2DM and related factors was collected from 2018 PC cases and 1540 controls from the PanGenEU (European Study into Digestive Illnesses and Genetics) study. A subset of PC cases and controls had glycated haemoglobin, C-peptide and genotype data. Multivariate logistic regression models were applied to derive ORs and 95% CIs. T2DM and PC-related single nucleotide polymorphism (SNP) were used as instrumental variables (IVs) in bidirectional MR analysis to test for two-way causal associations between PC, NODM and LSDM. Indirect and direct effects of the BMI-T2DM-PC association were further explored using mediation analysis.

RESULTS

T2DM was associated with an increased PC risk when compared with non-T2DM (OR=2.50; 95% CI: 2.05 to 3.05), the risk being greater for NODM (OR=6.39; 95% CI: 4.18 to 9.78) and insulin users (OR=3.69; 95% CI: 2.80 to 4.86). The causal association between T2DM (57-SNP IV) and PC was not statistically significant (OR_LSDM=1.08, 95% CI: 0.86 to 1.29, OR_NODM=1.06, 95% CI: 0.95 to 1.17). In contrast, there was a causal association between PC (40-SNP IV) and NODM (OR=2.85; 95% CI: 2.04 to 3.98), although genetic pleiotropy was present (MR-Egger: p value=0.03). Potential mediating effects of BMI (125-SNPs as IV), particularly in terms of weight loss, were evidenced on the NODM-PC association (indirect effect for BMI in previous years=0.55).

CONCLUSION

Findings of this study do not support a causal effect of LSDM on PC, but suggest that PC causes NODM. The interplay between obesity, PC and T2DM is complex.

Glycemic Status, Insulin Resistance, and Risk of Pancreatic Cancer Mortality in Individuals With and Without Diabetes

INTRODUCTION

The impact of glycemic status and insulin resistance on the risk of pancreatic cancer in the nondiabetic population remains uncertain. We aimed to examine the association of glycemic status and insulin resistance with pancreatic cancer mortality in individuals with and without diabetes.

METHODS

This is a cohort study of 572,021 Korean adults without cancer at baseline, who participated in repeat screening examinations which included fasting blood glucose, hemoglobin A1c, and insulin, and were followed for a median of 8.4 years (interquartile range, 5.3 -13.2 years). Vital status and pancreatic cancer mortality were ascertained through linkage to national death records.

RESULTS

During 5,211,294 person-years of follow-up, 260 deaths from pancreatic cancer were identified, with a mortality rate of 5.0 per 10 person-years. In the overall population, the risk of pancreatic cancer mortality increased with increasing levels of glucose and hemoglobin A1c in a dose-response manner, and this association was observed even in individuals without diabetes. In nondiabetic individuals without previously diagnosed or screen-detected diabetes, insulin resistance and hyperinsulinemia were positively associated with increased pancreatic cancer mortality. Specifically, the multivariable-adjusted hazard ratio (95% confidence intervals) for pancreatic cancer mortality comparing the homeostatic model assessment of insulin resistance ≥75th percentile to the <75th percentile was 1.49 (1.08-2.05), and the corresponding hazard ratio comparing the insulin ≥75th percentile to the <75th percentile was 1.43 (1.05-1.95). These associations remained significant when introducing changes in insulin resistance, hyperinsulinemia, and other confounders during follow-up as time-varying covariates.

DISCUSSION

Glycemic status, insulin resistance, and hyperinsulinemia, even in individuals without diabetes, were independently associated with an increased risk of pancreatic cancer mortality.

Diabetes Is Associated With the Metastasis of Pancreatic Neuroendocrine Tumors

OBJECTIVES

Type 2 diabetes mellitus (T2DM) has been associated with several types of cancers, but the role of T2DM in pancreatic neuroendocrine tumors (pNETs) has not been systematically studied.

METHODS

In this study, 299 patients with pNETs were recruited, and the clinicopathologic characteristics and prognosis of the diabetic and nondiabetic patients were compared. The association between metformin use and survival was assessed to examine whether metformin impacts the prognosis of pNETs patients.

RESULTS

The prevalence of T2DM in the cohort was 20.7% (n = 62). The proportions of grade 3 tumors, distant metastases, and nerve invasion in pNET patients with T2DM were higher than those in patients without T2DM, and as a result, the survival was worse in patients with T2DM. After adjusting for the tumor stage, diabetic status was not associated with poor survival in the univariate analysis. The results of logistic regression showed that pNET patients with T2DM were at high risk for tumor metastasis (odds ratio [OR], 2.81; P = 0.001), nerve invasion (OR, 2.43; P = 0.029), and grade 3 tumors (OR, 4.97; P = 0.010).

CONCLUSIONS

Type 2 diabetes mellitus is associated with pNET metastasis and not an independent risk factor for poor prognosis in pNETs.

Genome-wide association meta-analysis identifies GP2 gene risk variants for pancreatic cancer

Pancreatic cancer is the fourth leading cause of cancer-related deaths in Japan. To identify risk loci, we perform a meta-analysis of three genome-wide association studies comprising 2,039 pancreatic cancer patients and 32,592 controls in the Japanese population. Here, we identify 3 (13q12.2, 13q22.1, and 16p12.3) genome-wide significant loci (P < 5.0 × 10⁻⁸), of which 16p12.3 has not been reported in the Western population. The lead single nucleotide polymorphism (SNP) at 16p12.3 is rs78193826 (odds ratio = 1.46, 95% confidence interval = 1.29-1.66, P = 4.28 × 10⁻⁹), an Asian-specific, nonsynonymous glycoprotein 2 (GP2) gene variant. Associations between selected GP2 gene variants and pancreatic cancer are replicated in 10,822 additional cases and controls of East Asian origin. Functional analyses using cell lines provide supporting evidence of the effect of rs78193826 on KRAS activity. These findings suggest that GP2 gene variants are probably associated with pancreatic cancer susceptibility in populations of East Asian ancestry.

Previous genome-wide association studies have identified risk loci for pancreatic cancer but were centered on individuals of European ancestry. Here the authors identify GP2 gene variants associated with pancreatic cancer susceptibility in populations of East Asian ancestry.

Pancreatic Cancer in Iran: an Epidemiological Review

PURPOSE

Pancreatic cancer is the seventh cause of death in men in the world and also is one of the most common malignancies worldwide with poor prognosis. Due to the lack of epidemiological aspects of pancreatic cancer in Iran, this study aimed to investigate the epidemiological aspects of pancreatic cancer in Iran.

METHODS

In February 2019, A search was conducted with the keywords "Pancreatic Neoplasm," "Pancreas Neoplasms," "Cancer of Pancreas," "Pancreas Cancer," "Pancreatic Cancer," "Cancer of the Pancreas," and "Iran" in their title or abstract and MeSH. The databases of Medline, Web of Science, Scopus, SID, IranMedex, and Google Scholar were searched. The title and abstract of the papers were reviewed, and articles that addressed the epidemiological aspects of pancreatic cancer were included; in total, 20 full papers were reviewed.

RESULTS

According to studies, the incidence and mortality rate of pancreatic cancer is steadily increasing with age. Actually, men are more likely to develop this carcinoma than women. Smoking, aging, and lifestyle changes are the most important risk factors for pancreatic cancer in Iran. Due to the lack of initial symptoms or a specific marker for early diagnosis of pancreatic cancer, this cancer is detected lately and therefore low survival rate is observed.

CONCLUSION

Mortality and incidence of pancreatic cancer is increasing in Iran. Pancreatic cancer is more common in men than women. Based on the results of this study, pancreatic cancer depends largely on the lifestyle. Survival of pancreatic cancer is low in untreated patients.

Diabetes, Glycated Hemoglobin, and Risk of Cancer in the UK Biobank Study

BACKGROUND

Evidence suggest that diabetes and glycated hemoglobin (HbA1c) levels are associated with cancer risk. However, previous studies have been limited variably by failure to adjust for cancer-specific risk factors (e.g., body mass index), inattention to diabetes duration and use of antidiabetic medications, and failure to stratify by obesity.

METHODS

We examined the association between diabetes, HbA1c, and cancer risk in the UK Biobank, using data from 476,517 participants (54% women), followed for an average period of 7.1 years. Diabetes was defined on the basis of baseline self-reported diagnosis of diabetes and/or use of diabetes medication, while HbA1c measured at baseline was categorized as low (<31 mmol/mol), normal (31-<39 mmol/mol), increased risk (39-<48 mmol/mol), and high risk for diabetes (≥48 mmol/mol). Multivariable Cox proportional hazards models were used to estimate the association of diabetes and cancer at different anatomical sites, with adjustment for cancer-specific risk factors.

RESULTS

Diabetes was associated with increased risk of cancers of the stomach, liver, bladder, endometrium, and lung among smokers, and with decreased risk of prostate cancer. Compared with the normal HbA1c category, the increased risk category was positively associated with risk of cancers of the colon, liver, bladder, and lung among smokers, and the high-risk category was associated with increased risk of cancers of the esophagus, liver, pancreas, and bladder, and with decreased risk of prostate cancer.

CONCLUSIONS

These results suggest that both diabetes and/or elevated HbA1c are associated with risk of cancer at several anatomic sites.

IMPACT

The associations of diabetes and HbA1c levels with cancer suggest their importance in cancer prevention.

Obesity and pancreatic cancer: An update of epidemiological evidence and molecular mechanisms

Despite advances in therapy and achievements in translational research, pancreatic cancer (PC) remains an invariably fatal malignancy. Risk factors that affect the incidence of PC include diabetes, smoking, obesity, chronic pancreatitis, and diet. The growing worldwide obesity epidemic is associated with an increased risk of the most common cancers, including PC. Chronic inflammation, hormonal effects, circulating adipokines, and adipocyte-mediated inflammatory and immunosuppressive microenvironment are involved in the association of obesity with PC. Herein, we systematically review the epidemiology of PC and the biological mechanisms that may account for this association. Included in this review is a discussion of adipokine-mediated inflammation, lipid metabolism, and the interactions of adipocytes with cancer cells. We consider the influence of bariatric surgery on the risk of PC risk as well as potential molecular targets of therapy. Our review leads us to conclude that targeting adipose tissue to achieve weight loss may represent a new therapeutic strategy for preventing and treating PC.

The relationship between pancreatic cancer and type 2 diabetes: cause and consequence

Pancreatic cancer (PC) is a devastating and lethal malignant disease and it is well known that there is a complex bidirectional relationship between PC and type 2 diabetes mellitus (T2DM). In order to more deeply summarize the relationship between them, this article summarizes the epidemiological data on the relationship between PC and T2DM in the past 5 years, and further explains the mechanism of interaction between them. Meanwhile, it also summed up the effects of drug therapy for T2DM on PC and the impact of T2DM on surgical resection of PC. Epidemiological studies clearly indicate that the risk of PC is increased in patients with T2DM. But increasing epidemiological data points out that PC also acts as a cause of T2DM and new-onset T2DM is sign and consequence of PC. Insulin resistance, hyperinsulinemia, hyperglycemia, and chronic inflammation are the mechanisms of T2DM-Associated PC. Metformin decreases the risk of PC, while insulin therapy increases the risk of PC. Besides, studies have shown that T2DM decreases the survival in patients with PC resection.

Plasma C-peptide and glycated albumin and subsequent risk of cancer: From a large prospective case-cohort study in Japan

To elucidate the individual impacts of insulin and blood glucose on cancer risk, we investigated the association of plasma C-peptide, a surrogated marker of insulin and glycated albumin (GA), a more stable marker of blood glucose, with all-site and site-specific cancer risk by mutually accounting for their confounding effects. The study was prospectively conducted with nearly 4,000 cancer cases arising in our population-based cohort of 33,736 subjects who answered the baseline questionnaire and supplied blood samples. After exclusion of subjects with apparent DM, analysis was done in 3,036 cancer cases and 3,667 subcohort subjects. Among men and women combined, highest levels of C-peptide were statistically significantly associated with an increased risk of all-site [Hazard ratio (HR): 1.21; 95% confidence interval: 1.02-1.42], colon [1.73; 1.20-2.47], liver [3.23; 1.76-5.91], kidney, renal pelvis and ureter cancers [2.47; 1.07-5.69], compared to the respective lowest levels, after adjustment for GA levels. Among these C-peptide-related cancers, colon and liver cancers also showed an increased risk associated with elevated GA levels independently of C-peptide levels. The corresponding HRs for colon and liver cancers compared to the highest and lowest GA levels were 1.43 [1.02-2.00] and 2.02 [1.15-3.55], respectively. Effect modification by gender was only evident for the association between C-peptide and colon cancer (p for interaction = 0.04). Higher insulin levels, independently of higher blood glucose levels, may be relevant to DM-related carcinogenesis for several cancer sites. Examination of circulating insulin levels is a plausible option in evaluating cancer risk even in individuals who have not developed DM.

Obesity and the Risk of Gastrointestinal Cancers

Obesity is a risk factor for all major gastrointestinal cancers. With the rapid increase in the prevalence of obesity worldwide, this link could lead to an elevated burden of cancers of the digestive system. Currently, three main mechanisms explaining the link between excess adiposity and gastrointestinal cancer risk are being considered, including altered insulin signaling, obesity-associated chronic low-grade inflammation, and altered sex hormone metabolism, although new potential mechanisms emerge. This review is aimed to present our current knowledge on biological mechanisms involved in adiposity-related gastrointestinal carcinogenesis supported by results collected in epidemiological studies.

Pancreatic cancer: A review of clinical diagnosis, epidemiology, treatment and outcomes

This review aims to outline the most up-to-date knowledge of pancreatic adenocarcinoma risk, diagnostics, treatment and outcomes, while identifying gaps that aim to stimulate further research in this understudied malignancy. Pancreatic adenocarcinoma is a lethal condition with a rising incidence, predicted to become the second leading cause of cancer death in some regions. It often presents at an advanced stage, which contributes to poor five-year survival rates of 2%-9%, ranking firmly last amongst all cancer sites in terms of prognostic outcomes for patients. Better understanding of the risk factors and symptoms associated with this disease is essential to inform both health professionals and the general population of potential preventive and/or early detection measures. The identification of high-risk patients who could benefit from screening to detect pre-malignant conditions such as pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasms and mucinous cystic neoplasms is urgently required, however an acceptable screening test has yet to be identified. The management of pancreatic adenocarcinoma is evolving, with the introduction of new surgical techniques and medical therapies such as laparoscopic techniques and neo-adjuvant chemoradiotherapy, however this has only led to modest improvements in outcomes. The identification of novel biomarkers is desirable to move towards a precision medicine era, where pancreatic cancer therapy can be tailored to the individual patient, while unnecessary treatments that have negative consequences on quality of life could be prevented for others. Research efforts must also focus on the development of new agents and delivery systems. Overall, considerable progress is required to reduce the burden associated with pancreatic cancer. Recent, renewed efforts to fund large consortia and research into pancreatic adenocarcinoma are welcomed, but further streams will be necessary to facilitate the momentum needed to bring breakthroughs seen for other cancer sites.

Adiposity and gastrointestinal cancers: epidemiology, mechanisms and future directions

Excess adiposity is a risk factor for several cancers of the gastrointestinal system, specifically oesophageal adenocarcinoma and colorectal, small intestine, pancreatic, liver, gallbladder and stomach cancers. With the increasing prevalence of obesity in nearly all regions of the world, this relationship could represent a growing source of cancers of the digestive system. Experimental and molecular epidemiological studies indicate important roles for alterations in insulin signalling, adipose tissue-derived inflammation and sex hormone pathways in mediating the association between adiposity and gastrointestinal cancer. The intestinal microbiome, gut hormones and non alcoholic fatty liver disease (NAFLD) also have possible roles. However, important gaps remain in our knowledge. For instance, our understanding of how adiposity throughout the life course is related to the risk of gastrointestinal cancer development and of how obesity influences gastrointestinal cancer prognosis and survival is limited. Nonetheless, the increasing use of state-of-the-art analytical methods (such as omics technologies, Mendelian randomization and MRI) in large-scale epidemiological studies offers exciting opportunities to advance our understanding of the complex relationship between adiposity and gastrointestinal cancers. Here, we examine the epidemiology of associations between obesity and gastrointestinal cancer, explore potential mechanisms underlying these relationships and highlight important unanswered research questions.

Dietary oleic acid is inversely associated with pancreatic cancer - Data from food diaries in a cohort study

BACKGROUND

Dietary oleic acid may prevent pancreatic ductal adenocarcinoma (PDA) by reducing hyperinsulinaemia which can otherwise promote DNA damage and tumour growth. Results from previous epidemiological studies investigating oleic acid are inconsistent. This study aims to clarify the relationship between dietary oleic acid intake and the risk of developing PDA using nutritional information from food diaries plus published serum biomarker data from HbA1c.

METHODS

23,658 participants, aged 40-74 years, were recruited into EPIC-Norfolk and completed 7-day food diaries which recorded; foods, brands and portion sizes to calculate nutrient intakes. Serum HbA1c was measured at recruitment in 11,147 participants (48.7% of cohort). Hazard ratios (HRs) for quintiles of dietary oleic acid intake and serum HbA1c were estimated using Cox regression. Additional analyses were made according to whether body mass index (BMI) was greater or less than 25 kg/m² as this influences hyperinsulinaemia.

RESULTS

88 participants (55% women) developed PDA after a mean follow-up of 8.4 years (SD = 3.9) (mean age at diagnosis = 72.6 years, SD = 8.8). A decreased risk of PDA was associated with increased dietary oleic acid intake (highest vs lowest quintile, HR = 0.29, 95% CI = 0.10-0.81, P trend across quintiles = 0.011), with statistical significance maintained when BMI>25 kg/m² but not if BMI<25 kg/m². An elevated serum HbA1c was associated with increased risk of disease (highest vs lowest quintiles, HR = 6.32, 95% CI = 1.38-28.89, P for trend = 0.004).

CONCLUSIONS

The data supports a protective role of oleic acid against development of PDA in those with higher BMIs possibly through influencing hyperinsulinaemia. Oleic acid intake should be accurately measured in future aetiological studies.

Obesity, Inflammation, and Cancer

Obesity, a worldwide epidemic, confers increased risk for multiple serious conditions, including cancer, and is increasingly recognized as a growing cause of preventable cancer risk. Chronic inflammation, a well-known mediator of cancer, is a central characteristic of obesity, leading to many of its complications, and obesity-induced inflammation confers additional cancer risk beyond obesity itself. Multiple mechanisms facilitate this strong association between cancer and obesity. Adipose tissue is an important endocrine organ, secreting several hormones, including leptin and adiponectin, and chemokines that can regulate tumor behavior, inflammation, and the tumor microenvironment. Excessive adipose expansion during obesity causes adipose dysfunction and inflammation to increase systemic levels of proinflammatory factors. Cells from adipose tissue, such as cancer-associated adipocytes and adipose-derived stem cells, enter the cancer microenvironment to enhance protumoral effects. Dysregulated metabolism that stems from obesity, including insulin resistance, hyperglycemia, and dyslipidemia, can further impact tumor growth and development. This review describes how adipose tissue becomes inflamed in obesity, summarizes ways these mechanisms impact cancer development, and discusses their role in four adipose-associated cancers that demonstrate elevated incidence or mortality in obesity.

Obesity and Pancreatic Cancer

Pancreatic cancer has few known risk factors, providing little in the way of prevention, and is the most rapidly fatal cancer with 7 % survival rate at 5 years. Obesity has surfaced as an important risk factor for pancreatic cancer as epidemiological studies with strong methodological designs have removed important biases and solidified the obesity associations. Moreover, studies indicate that obesity early in adulthood is strongly associated with future risk of pancreatic cancer and that abdominal obesity is an independent risk factor. There is increasing evidence suggesting long-standing diabetes type 2 and insulin resistance are important etiological factors of this disease, providing a strong mechanistic link to obesity. The challenge remains to determine whether intended weight loss in midlife will reduce risk of pancreatic cancer and to elucidate the complex underlying pathways directly involved with risk.

Serum C-peptide, Total and High Molecular Weight Adiponectin, and Pancreatic Cancer: Do Associations Differ by Smoking?

Background: Studies examining associations between circulating concentrations of C-peptide and total adiponectin, two biomarkers related to obesity and insulin secretion and sensitivity and pancreatic ductal adenocarcinoma (PDA) risk have shown inconsistent results and included limited numbers of smokers.Methods: We examined associations of these biomarkers and high molecular weight (HMW) adiponectin with PDA, overall, and by smoking status. We conducted a pooled nested case-control analysis in 3 cohorts (Prostate, Lung, Colorectal, and Ovarian Cancer Trial, Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, and Cancer Prevention Study-II), with 758 cases (435 current smokers) and 1,052 controls (531 smokers) matched by cohort, age, sex, race, blood draw date and follow-up time. We used conditional logistic regression adjusted for age, smoking, diabetes, and body mass index to calculate ORs and 95% confidence intervals (CI).Results: Circulating C-peptide concentration was not associated with PDA in never or former smokers, but was inversely associated with PDA in current smokers (per SD OR = 0.67; 95% CI, 0.54-0.84; Pinteraction = 0.005). HMW adiponectin was inversely associated with PDA in never smokers (OR = 0.43; 95% CI, 0.23-0.81), not associated in former smokers, and positively associated in smokers (OR = 1.23; 95% CI, 1.04-1.45; Pinteraction = 0.009). Total adiponectin was not associated with PDA in nonsmokers or current smokers.Conclusions: Associations of biomarkers of insulin secretion and sensitivity with PDA differ by smoking status. Smoking-induced pancreatic damage may explain the associations in smokers while mechanisms related to insulin resistance associations in nonsmokers.Impact: Future studies of these biomarkers and PDA should examine results by smoking status. Cancer Epidemiol Biomarkers Prev; 26(6); 914-22. ©2017 AACR.

Diabetes, plasma glucose and incidence of pancreatic cancer: A prospective study of 0.5 million Chinese adults and a meta-analysis of 22 cohort studies

Diabetes is associated with an increased risk of pancreatic cancer (PC) in Western populations. Uncertainty remains, however, about the relevance of plasma glucose for PC among people without diabetes and about the associations of diabetes and high blood glucose with PC in China where the increase in diabetes prevalence has been very recent. The prospective China Kadoorie Biobank (CKB) study recruited 512,000 adults aged 30‐79 years from 10 diverse areas of China during 2004‐2008, recording 595 PC cases during 8 years of follow‐up. Cox regression yielded adjusted hazard ratios (HRs) for PC associated with diabetes (previously diagnosed or screen‐detected) and, among those without previously diagnosed diabetes, with levels of random plasma glucose (RPG). These were further meta‐analysed with 22 published prospective studies. Overall 5.8% of CKB participants had diabetes at baseline. Diabetes was associated with almost twofold increased risk of PC (adjusted HR = 1.87, 95% CI 1.48‐2.37), with excess risk higher in those with longer duration since diagnosis (p for trend = 0.01). Among those without previously diagnosed diabetes, each 1 mmol/L higher usual RPG was associated with a HR of 1.12 (1.04‐1.21). In meta‐analysis of CKB and 22 other studies, previously diagnosed diabetes was associated with a 52% excess risk (1.52, 1.43‐1.63). Among those without diabetes, each 1 mmol/L higher blood glucose was associated with a 15% (1.15, 1.09‐1.21) excess risk. In Chinese and non‐Chinese populations, diabetes and higher blood glucose levels among those without diabetes are associated with an increased risk of PC.

What's new?

Diabetes is associated with increased risk of pancreatic cancer (PC) in Western populations, but uncertainty remains about the relevance of plasma glucose among people without diabetes. In this first prospective study investigating the association of diabetes with PC risk in China, where the increase in diabetes prevalence has been very recent, diabetes was associated with an almost twofold increased risk of PC, with random plasma glucose being positively associated with PC risk among participants without prior diagnosis of diabetes. In meta‐analysis, the results were consistent with previous evidence in Western populations, highlighting diabetes as a potential aetiological factor of PC.

Insulin resistance is associated with the aggressiveness of pancreatic ductal carcinoma

AIMS

To study whether insulin resistance accelerates the development and/or the progression of pancreatic adenocarcinoma (PDAC), we hypothesized that patients with insulin resistance, compared with those without insulin resistance, show: (1) a younger age and more advanced PDAC stage at diagnosis and (2) a shorter disease-free and overall survival after PDAC diagnosis.

METHODS

Prospective observational study of patients admitted to a referral center for pancreatic disease. Insulin resistance was defined as a HOMA-IR value greater than the 66th percentile value of the patients included in this study. Survival was estimated according to Kaplan-Meier and by Cox regression.

RESULTS

Of 296 patients with PDAC, 99 (33 %) met criteria for being classified as insulin resistant at diagnosis. Median follow-up time after diagnosis was 5.27 ± 0.23 years. Patients with insulin resistance received a diagnosis of PDAC at a similar age compared to patients without insulin resistance (67.1 ± 9 vs. 66.8 ± 10 years, p = 0.68), but were more likely to have a cancer stage ≥3 (23.2 vs. 14.2 %, p = 0.053) and a residual disease after surgery (R1 56.4 vs. 38 %; p = 0.007). The median overall survival was 1.3 ± 0.14 and 1.79 ± 0.11 years for the patients with and without insulin resistance, respectively (p = 0.016). Results did not change when patients with diabetes at PDAC diagnosis were excluded from the analysis. Multivariate analysis showed that insulin resistance was independently associated with overall survival.

CONCLUSIONS

Insulin resistance is associated with the aggressiveness of PDAC.

Sweet-beverage consumption and risk of pancreatic cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)

BACKGROUND

The consumption of sweet beverages has been associated with greater risk of type 2 diabetes and obesity, which may be involved in the development of pancreatic cancer. Therefore, it has been hypothesized that sweet beverages may increase pancreatic cancer risk as well.

OBJECTIVE

We examined the association between sweet-beverage consumption (including total, sugar-sweetened, and artificially sweetened soft drink and juice and nectar consumption) and pancreatic cancer risk.

DESIGN

The study was conducted within the European Prospective Investigation into Cancer and Nutrition cohort. A total of 477,199 participants (70.2% women) with a mean age of 51 y at baseline were included, and 865 exocrine pancreatic cancers were diagnosed after a median follow-up of 11.60 y (IQR: 10.10-12.60 y). Sweet-beverage consumption was assessed with the use of validated dietary questionnaires at baseline. HRs and 95% CIs were obtained with the use of multivariable Cox regression models that were stratified by age, sex, and center and adjusted for educational level, physical activity, smoking status, and alcohol consumption. Associations with total soft-drink consumption were adjusted for juice and nectar consumption and vice versa.

RESULTS

Total soft-drink consumption (HR per 100 g/d: 1.03; 95% CI: 0.99, 1.07), sugar-sweetened soft-drink consumption (HR per 100 g/d: 1.02; 95% CI: 0.97, 1.08), and artificially sweetened soft-drink consumption (HR per 100 g/d: 1.04; 95% CI: 0.98, 1.10) were not associated with pancreatic cancer risk. Juice and nectar consumption was inversely associated with pancreatic cancer risk (HR per 100 g/d: 0.91; 95% CI: 0.84, 0.99); this association remained statistically significant after adjustment for body size, type 2 diabetes, and energy intake.

CONCLUSIONS

Soft-drink consumption does not seem to be associated with pancreatic cancer risk. Juice and nectar consumption might be associated with a modest decreased pancreatic cancer risk. Additional studies with specific information on juice and nectar subtypes are warranted to clarify these results.

Relationship between HbA1c and cancer in people with or without diabetes: a systematic review

AIM

To identify the relationship between HbA1c and cancers in people with or without diabetes.

BACKGROUND

Cancer is a major public health problem, accounting for 8.2 million deaths worldwide in 2012. HbA1c level has been associated with the risk of developing certain cancers, although the existing evidence is conflicting.

METHODS

EMBASE, MEDLINE, CINAHL and the Cochrane Library were searched. Eligible articles included randomized controlled trials, cohort studies, case-control studies, systematic reviews and meta-analyses. Participants of either sex, with or without Type 1 or 2 diabetes, were included. The studies were assessed using the Scottish Intercollegiate Guidelines Network (SIGN) criteria by two independent assessors. No meta-analysis was performed because of the heterogeneity of results.

RESULTS

A total of 19 studies from 1006 met the inclusion criteria, of which 14 were cohort studies and five were nested case-control studies. Eight studies investigated outcomes for all cancer sites. Four of these studies reported that higher HbA1c levels were associated with higher incidence and/or mortality risk for all cancers. One study observed a U-shaped relationship between HbA1c and cancer incidence and mortality. Increasing HbA1c levels were associated with increasing risk of developing colorectal, pancreatic, respiratory and female genital tract cancers. No increased risk was observed for breast cancer, gastrointestinal or urological malignancies.

CONCLUSION

HbA1c appears to be associated with cancer incidence and/or cancer mortality, but further studies are needed to fully understand the complex relationship between HbA1c and cancer.

Epidemiology and Inherited Predisposition for Sporadic Pancreatic Adenocarcinoma

Given the changing demographics of Western populations, the numbers of pancreatic cancer cases are projected to increase during the next decade. Diabetes, recent cigarette smoking, and excess body weight are the cancer's most consistent risk factors. The search for common and rare germline variants that influence risk of pancreatic cancer through genome-wide association studies and high-throughput-sequencing-based studies is underway and holds the promise of increasing the knowledge of variants and genes that play a role in inherited susceptibility of this disease. Research reported in this review has advanced the understanding of pancreatic cancer.

Type 2 Diabetes Mellitus and Its Association with the Risk of Pancreatic Carcinogenesis: A Review

The prevalence of diabetes mellitus (DM) and associated diseases such as cancers are substantially increasing worldwide. About 80% of the patients with pancreatic cancer have glucose metabolism alterations. This suggests an association between type 2 DM and pancreatic cancer risk and progression. There are hypotheses that show metabolic links between the diseases, due to insulin resistance, hyperglycemia, hyperinsulinemia, low grade chronic inflammation, and alteration in the insulin-insulin-like growth factor axis. The use of diabetes medications can influence the extent of carcinogenesis of the pancreas. This study briefly reviews recent literature on investigation of metabolic link of type 2 DM, risk of carcinogenesis of the pancreas and their association, as well as the current understanding of metabolic pathways implicated in metabolism and cellular growth. The main finding of this review, although there are discrepancies, is that according to most research long-term DM does not raise the risk of pancreatic cancer. The longest duration of DM may reflect hypoinsulinemia due to treatment for hyperglycemia, but recent onset diabetes was associated with increased risk for pancreatic cancer due to hyperinsulinemia and hyperglycemia. In conclusion, the review demonstrates that type 2 DM and the duration of diabetes pose a risk for pancreatic carcinogenesis, and that there is biological link between the diseases.

Premorbid Obesity and Mortality in Patients With Pancreatic Cancer: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Obesity is associated with an increased risk for pancreatic cancer, but it is unclear whether it affects mortality. We performed a systematic review and meta-analysis to assess the association between premorbid obesity and mortality from pancreatic cancer.

METHODS

We performed a systematic search through January 2015 and identified studies of the association between premorbid obesity (at least 1 year prior to pancreatic cancer diagnosis) and pancreatic cancer-related mortality. We estimated summary adjusted hazard ratio (aHR) with 95% confidence interval (CI), comparing data from obese (body mass index [BMI] ≥30 kg/m(2)) and overweight subjects (BMI, 25.0-29.9 kg/m(2)) with those from individuals with a normal BMI (controls) by using random-effects model.

RESULTS

We identified 13 studies (including 3 studies that pooled multiple cohorts); 5 studies included only patients with pancreatic cancer, whereas 8 studies evaluated pancreatic cancer-related mortality in cancer-free individuals at inception. In the meta-analysis, we observed increase in pancreatic cancer-related mortality among overweight (aHR, 1.06; 95% CI, 1.02-1.11; I(2) = 0) and obese individuals (aHR, 1.31; 95% CI, 1.20-1.42; I(2) = 43%), compared with controls; the association remained when we analyzed data from only subjects with pancreatic cancer. Each 1 kg/m(2) increase in BMI was associated with 10% increase in mortality (aHR, 1.10; 95% CI, 1.05-1.15) with minimal heterogeneity (I(2) = 0). In the subgroup analysis, obesity was associated with increased mortality in Western populations (11 studies; aHR, 1.32; 95% CI, 1.22-1.42) but not in Asia-Pacific populations (2 studies; aHR, 0.98; 95% CI, 0.76-1.27).

CONCLUSIONS

In a systematic review and meta-analysis, we associated increasing level of obesity with increased mortality in patients with pancreatic cancer in Western but not Asia-Pacific populations. Strategies to reduce obesity-induced metabolic abnormalities might be developed to treat patients with pancreatic cancer.

New-onset type 2 diabetes, elevated HbA1c, anti-diabetic medications, and risk of pancreatic cancer

Background:

Associations between type 2 diabetes, anti-diabetic medications and pancreatic cancer are controversial. This study aims to clarify such associations with new-onset type 2 diabetes and repeated measurements of glycated haemoglobin (HbA1c) levels.

Methods:

A nested case–control study was initiated from the Health Improvement Network (THIN) in UK from 1996 to 2010. Information of pancreatic cancer cases was retrieved electronically from the medical records and manually validated. Control subjects were randomly selected and frequency-matched to the cases on sex, age, and calendar years. Multivariable unconditional logistic regression was performed to estimate odds ratios (OR) and 95% confidence intervals (CI), and adjusted for potential confounders.

Results:

Among 1 574 768 person-years of follow-up, 529 pancreatic cancer cases and 5000 controls were identified. Type 2 diabetes, or changed HbA1c levels (rather than HbA1c levels at diabetes diagnosis) in diabetes patients (⩾4 mmol mol⁻¹ compared with <0 mmol mol⁻¹) were followed by an increased OR of pancreatic cancer (OR, 2.16, 95% CI 1.72–2.72 and OR, 5.06, 95% CI 1.52–16.87, respectively). Among the anti-diabetic medications in diabetes patients, the OR for insulin users was 25.57 (95% CI 11.55–56.60), sulphonylureas 2.22 (95% CI 1.13, 4.40), and metformin users 1.46 (95% CI 0.85–2.52), compared with no use of any anti-diabetic medications.

Conclusions:

New-onset type 2 diabetes and, particularly, diabetes with rising HbA1c seem to be independent risk factors for pancreatic cancer. The relation between different anti-diabetic medications and pancreatic cancer seems to vary in strength, with the highest risk among users of insulin.

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.

Pattern of increasing HbA1c levels in patients with diabetes mellitus before clinical detection of pancreatic cancer - a population-based nationwide case-control study

BACKGROUND

Diabetes mellitus is a risk factor for pancreatic cancer. Impaired insulin resistance might precede the clinical detection of this cancer by several years.

METHODS

This was a nested case-control population-based study assessing the pattern of glycated hemoglobin (HbA1c) change before clinical detection of pancreatic cancer in a population of individuals with diabetes mellitus. All patients registered in the Swedish National Diabetes Register with a prescription of an anti-diabetic drug between 2005 and 2011 were identified. For each case of pancreatic cancer, 10 controls were randomly selected, matched for age, sex, and factors related to diabetes mellitus. Multivariable conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between HbA1c and pancreatic cancer.

RESULTS

In total, 391 cases and 3910 matched controls were identified. The risk of pancreatic cancer was increased more than two-fold in individuals with the highest HbA1c quartile compared with the lowest (OR 1.96, 95% CI 1.40-2.75). The risk of pancreatic cancer remained elevated when comparing the highest HbA1c quartile measured within five years from the clinical detection of pancreatic cancer to the lowest HbA1c quartile (p-value for trend < 0.05). No association was found between HbA1c and pancreatic cancer if HbA1c was measured > 5 years before the clinical detection of pancreatic cancer.

CONCLUSIONS

The pattern of increasing HbA1c in patients with diabetes mellitus preceded the clinical detection of pancreatic cancer by up to five years. These findings indicate that there is a lead time of several years during which the development of pancreatic cancer might be detectable through screening in patients with diabetes mellitus.

Dietary food groups intake and cooking methods associations with pancreatic cancer: a case-control study

BACKGROUND

The role of dietary habits in the etiology of pancreatic cancer (PC) has not yet been well elucidated.

AIM

The aim of the present study was to examine the association of the frequency of different food groups' intake and their cooking methods with PC risk based on a well-designed case-control study.

METHODS

A case-control study including 307 PC patients and 322 controls referred to four tertiary endosonography centers was conducted from January 2011 to January 2014 to compare the frequency intake of different food items and their cooking methods between cases and controls.

RESULTS

After adjustment for gender, age, body mass index, years of education, diabetes and alcohol history, smoking status, and opium use, a significant direct relationship was observed between PC risk and intake frequency (time/week) of bread (OR = 1.50; 95 % CI 1.05-2.13; p-value 0.024), rice (OR = 2.10; 95 % CI 1.15-3.82; p for trend 0.034), and red meat (OR = 2.25; 95 % CI 1.22-4.14; p for trend 0.033) (time/day), when comparing the highest category of intake frequency with the lowest, while increasing frequency of fish consumption was associated with a lower risk of PC (OR = 0.93; 95 % CI0.59-1.47; p for trend 0.009). Increasing consumption of barbecuing red meat and deep fried vegetables was associated with 67 % and 70 % increased risk of PC (p-value 0.025 and 0.006, respectively).

CONCLUSION

Our results indicate that increased frequency of intake of bread, rice, and red meat (especially barbecued) and deep fried vegetables can aggregate PC risk, while increased frequency of fish consumption can protect against PC. However, more studies are still needed.

Blood glucose concentration and risk of pancreatic cancer: systematic review and dose-response meta-analysis

OBJECTIVE

To evaluate potential linear and non-linear dose-response relations between blood glucose and risk of pancreatic cancer.

DESIGN

Systematic review and dose-response meta-analysis of prospective observational studies.

DATA SOURCES

Search of PubMed, Scopus, and related reviews before 30 November 2013 without language restriction.

ELIGIBILITY CRITERIA

Prospective studies evaluating the association between blood glucose concentration and pancreatic cancer. Retrospective and cross sectional studies excluded to avoid reverse causality.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted relevant information and assessed study quality with the Newcastle-Ottawa scale. Random effects dose-response meta-analysis was conducted to assess potential linear and non-linear dose-response relations.

RESULTS

Nine studies were included for analysis, with a total of 2408 patients with pancreatic cancer. There was a strong linear dose-response association between fasting blood glucose concentration and the rate of pancreatic cancer across the range of prediabetes and diabetes. No non-linear association was detected. The pooled rate ratio of pancreatic cancer per 0.56 mmol/L (10 mg/dL) increase in fasting blood glucose was 1.14 (95% confidence interval 1.06 to 1.22; P<0.001) without significant heterogeneity. Sensitivity analysis excluding blood glucose categories in the range of diabetes showed similar results (pooled rate ratio per 0.56 mmol/L increase in fasting blood glucose was 1.15, 95% confidence interval 1.05 to 1.27; P=0.003), strengthening the association between prediabetes and pancreatic cancer.

CONCLUSIONS

Every 0.56 mmol/L increase in fasting blood glucose is associated with a 14% increase in the rate of pancreatic cancer. As prediabetes can be improved or even reversed through lifestyle changes, early detection of prediabetes coupled with lifestyle changes could represent a viable strategy to curb the increasing incidence of pancreatic cancer.

Leukocyte telomere length in relation to pancreatic cancer risk: a prospective study

BACKGROUND

Several studies have examined leukocyte telomere length (LTL) as a possible predictor for cancer at various organ sites. The hypothesis originally motivating many of these studies was that shorter telomeres would be associated with an increase in cancer risk; the results of epidemiologic studies have been inconsistent, however, and suggested positive, negative, or null associations. Two studies have addressed the association of LTL in relation to pancreatic cancer risk and the results are contrasting.

METHODS

We measured LTL in a prospective study of 331 pancreatic cancer cases and 331 controls in the context of the European Prospective Investigation into Cancer and Nutrition (EPIC).

RESULTS

We observed that the mean LTL was higher in cases (0.59 ± 0.20) than in controls (0.57 ± 0.17), although this difference was not statistically significant (P = 0.07), and a basic logistic regression model showed no association of LTL with pancreas cancer risk. When adjusting for levels of HbA1c and C-peptide, however, there was a weakly positive association between longer LTL and pancreatic cancer risk [OR, 1.13; 95% confidence interval (CI), 1.01-1.27]. Additional analyses by cubic spline regression suggested a possible nonlinear relationship between LTL and pancreatic cancer risk (P = 0.022), with a statistically nonsignificant increase in risk at very low LTL, as well as a significant increase at high LTL.

CONCLUSION

Taken together, the results from our study do not support LTL as a uniform and strong predictor of pancreatic cancer.

IMPACT

The results of this article can provide insights into telomere dynamics and highlight the complex relationship between LTL and pancreatic cancer risk.

Diabetes and cancer: epidemiology and potential mechanisms

Type 2 diabetes mellitus is an independent risk factor for cancer such as pancreatic, liver, colorectal and breast cancer. In addition, diabetes decreases the risk of prostate cancer. These associations have been found in numerous epidemiological studies, among them several prospective cohorts. However, such studies do not prove causality of the association and cannot exclude inadequate correction for known confounders (e.g. visceral fat) or the influence of unknown confounders. Thus, it is unclear whether the cancer risk is increased by the causes (e.g. the metabolic syndrome), the metabolic consequences (e.g. hyperglycaemia) or the therapy of diabetes; a question which is of major importance for therapeutic guidelines. Identification of the potential mechanisms by which the diabetes or its therapy accelerates or inhibits the development of cancer will help answering the question by providing biological plausibility. This review will summarize the evidence supporting the association of cancer and type 2 diabetes and discuss its potential causes.