Pancreatic cancer risk: associations with meat-derived carcinogen intake in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort

Polycyclic Aromatic Hydrocarbons and Pancreatic Cancer: An Analysis of the Blood Biomarker, r-1,t-2,3,c-4-Tetrahydroxy-1,2,3,4-tetrahydrophenanthrene and Selected Metabolism Gene SNPs

Exposure to polycyclic aromatic hydrocarbons (PAHs), byproducts of incomplete combustion, and their effects on the development of cancer are still being evaluated. Recent studies have analyzed the relationship between PAHs and tobacco or dietary intake in the form of processed foods and smoked/well-done meats. This study aims to assess the association of a blood biomarker and metabolite of PAHs, r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), dietary intake, selected metabolism SNPs, and pancreatic cancer. Demographics, food-frequency data, SNPs, treatment history, and levels of PheT in plasma were determined from 400 participants (202 cases and 198 controls) and evaluated based on pancreatic adenocarcinoma diagnosis. Demographic and dietary variables were selected based on previously published literature indicating association with pancreatic cancer. A multiple regression model combined the significant demographic and food items with SNPs. Final multivariate logistic regression significant factors (p-value < 0.05) associated with pancreatic cancer included: Type 2 Diabetes [OR = 6.26 (95% CI = 2.83, 14.46)], PheT [1.03 (1.02, 1.05)], very well-done red meat [0.90 (0.83, 0.96)], fruit/vegetable servings [1.35 (1.06, 1.73)], recessive (rs12203582) [4.11 (1.77, 9.91)], recessive (rs56679) [0.2 (0.06, 0.85)], overdominant (rs3784605) [3.14 (1.69, 6.01)], and overdominant (rs721430) [0.39 (0.19, 0.76)]. Of note, by design, the level of smoking did not differ between our cases and controls. This study does not provide strong evidence that PheT is a biomarker of pancreatic cancer susceptibility independent of dietary intake and select metabolism SNPs among a nonsmoking population.

A blood-based metabolomic signature predictive of risk for pancreatic cancer

Emerging evidence implicates microbiome involvement in the development of pancreatic cancer (PaCa). Here, we investigate whether increases in circulating microbial-related metabolites associate with PaCa risk by applying metabolomics profiling to 172 sera collected within 5 years prior to PaCa diagnosis and 863 matched non-subject sera from participants in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cohort. We develop a three-marker microbial-related metabolite panel to assess 5-year risk of PaCa. The addition of five non-microbial metabolites further improves 5-year risk prediction of PaCa. The combined metabolite panel complements CA19-9, and individuals with a combined metabolite panel + CA19-9 score in the top 2.5th percentile have absolute 5-year risk estimates of >13%. The risk prediction model based on circulating microbial and non-microbial metabolites provides a potential tool to identify individuals at high risk of PaCa that would benefit from surveillance and/or from potential cancer interception strategies.

The association between red, processed and white meat consumption and risk of pancreatic cancer: a meta-analysis of prospective cohort studies

PURPOSE

The association between meat consumption and the risk of pancreatic cancer has not been comprehensively investigated by different types of meat. The current study was conducted to evaluate this association.

METHODS

PubMed and Web of Science databases were used to search for prospective cohort studies on meat consumption and pancreatic cancer risk through May 2022. A meta-analysis was performed using random-effects models to combine study-specific relative risks (RR). The quality of the included studies was evaluated using the Newcastle-Ottawa quality assessment scale.

RESULTS

Twenty prospective cohort studies including 3,934,909 participants and 11,315 pancreatic cancer cases were identified. The pooled RR of pancreatic cancer for the highest versus lowest white meat intake category was 1.14 (95% CI: 1.03-1.27). There was no significant association between consumption of red meat and processed meat and pancreatic cancer risk in the highest versus lowest analysis. In dose-response analyses, pooled RRs were 1.14 (95% CI: 1.01-1.28) for an increase in red meat consumption of 120 g per day and 1.26 (95% CI: 1.08-1.47) for an increase in white meat consumption of 100 g per day, respectively. Processed meat consumption showed neither a linear nor a non-linear association with pancreatic cancer risk.

CONCLUSION

Findings from this meta-analysis suggested that high consumption of red meat and white meat is associated with an increased risk of pancreatic cancer. Future prospective studies are warranted to confirm the association between meat consumption and the risk of pancreatic cancer.

What Dietary Patterns and Nutrients are Associated with Pancreatic Cancer? Literature Review

This narrative review summarizes the main findings of observational studies (case-control and cohort) as well as systematic reviews and meta-analyses on the role of nutrients and dietary patterns on pancreatic cancer (PC) risk and elucidates possible mechanisms for the association between nutrients or specific food components and the risk of PC. A literature search of MEDLINE (PubMed), Google Scholar, ScienceDirect, and Scopus was performed. An extensive search of related articles published in the English language from 1985 to 2022 was carried out. Our search included macro- and micronutrient intake as well as dietary patterns associated with PC. In conclusion, the consumption of a diet high in nutrients such as sugar, fats, and red and processed meats can increase the risk of PC. Conversely, a high dietary intake of fresh fruit and vegetables and their associated nutrients like fiber, antioxidants, and polyphenols may prevent PC. Dietary patterns loaded with red and processed meats were also linked to an increased risk of PC, whereas dietary patterns rich in plant-based foods like vegetables, fruits, whole grains, and legumes were associated with a reduced risk of PC. Dietary fiber, fat-soluble vitamins, water-soluble vitamins, and minerals might also play a protective role against PC.

Obesity, diabetes mellitus, and pancreatic carcinogenesis: Correlations, prevention, and diagnostic implications

The prevalence of obesity, diabetes mellitus (DM), and pancreatic cancer (PC) has been consistently increasing in the last two decades worldwide. Sharing various influential risk factors in genetics and environmental inducers in pathogenesis, the close correlations of these three diseases have been demonstrated in plenty of clinical studies using multiple parameters among different populations. On the contrary, most measures aimed to manage and treat obesity and DM effectively reduce the risk and prevent PC occurrence, yet certain drugs can inversely promote pancreatic carcinogenesis instead. Most importantly, an elevation of blood glucose with or without a reduction in body weight, along with other potential tools, may provide valuable clues for detecting PC at an early stage in patients with obesity and DM, favoring a timely intervention and prolonging survival. Herein, the epidemiological and etiological correlations among these three diseases and the supporting clinical evidence of their connections are first summarized to favor a better and more thorough understanding of obesity- and DM-related pancreatic carcinogenesis. After comparing the distinct impacts of different weight-lowering and anti-diabetic treatments on the risk of PC, the possible diagnostic implications of hyperglycemia and weight loss in PC screening are also addressed in detail.

Dietary meat mutagens intake and cancer risk: A systematic review and meta-analysis

Background

Clinical and preclinical studies suggested that certain mutagens occurring as a reaction of creatine, amino acids, and sugar during the high temperature of cooking meat are involved in the pathogenesis of human cancer. Here we conducted a systematic review and meta-analysis to examine whether meat mutagens [PhIP, MeIQx, DiMeIQx, total HCA, and B(a)P] present a risk factor for human cancer.

Methods

We searched the following databases for relevant articles published from inception to 10 Oct 2021 with no language restrictions: Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Baidu Academic, Zhejiang Digital Library. Two independent researchers screened all titles and obtained eligible texts for further screening. Independent data extraction was conducted, and meta-analysis was carried out using random-effects models to calculate the risk ratio of the meat mutagens exposure.

Results

A total of 1,786,410 participants and 70,653 cancer cases were identified. Among these, there were 12 different types of cancer at various sites, i.e., breast, bladder, colorectal, colon, rectum, prostate, lung, Non-Hodgkin lymphoma, kidney, gastric, esophagus, pancreatic, hepatocellular carcinoma. Cancer risk was significantly increased by intake of PhIP (OR = 1.13;95% CI 1.07–1.21; p < 0.001), MeIQx (OR = 1.14; 95% CI: 1.07–1.21; p < 0.001), DiMeIQx (OR = 1.07; 95% CI: 1.01–1.13; p = 0.013), total HCA (OR = 1.20; 95% CI: 1.03–1.38; p = 0.016), and cancer risk was not significantly increased by intake of B(a)P (OR = 1.04; 95% CI: 0.98–1.10; p = 0.206).

Conclusion

Meat mutagens of PhIP, MeIQx, DiMeIQx, and total HCA have a positive association with the risk of cancer.

Systematic review registration

[www.crd.york.ac.uk/prospero], identifier [CRD42022148856].

Factors associated with pancreatic cancer in Spain. What can we learn from epidemiological studies?

The incidence of pancreatic cancer (PC) in Spain has progressively increased over the past 6 decades. Pancreatic ductal adenocarcinoma represents over 80 % of all pancreatic neoplasms. The study by Enrique Gili-Ortiz on pancreatic cancer-related mortality trends in Spain revealed a significant increase in death rates in our country, which may be partly attributed to population ageing and increased smoking, obesity, and diabetes rates. Other known factors, including chronic pancreatitis, seem to play a less significant role from a quantitative perspective.

Trends in Pancreatic Cancer Incidence and Mortality in Lithuania, 1998-2015

BACKGROUND

Pancreatic cancer is one of the deadliest cancers worldwide, and its incidence is increasing. The aim of this study was to examine the time trends in the incidence and mortality rates of pancreatic cancer for the period of 1998-2015 for the first time in Lithuania by sex, age, subsite, and stage.

METHODS

This study was based on all cases (deaths) of pancreatic cancer diagnosed between 1998 and 2015. Age-standardized incidence (mortality) rates and group-specific rates were calculated for each sex using the direct method (European Standard). TNM classification-based information reported to the cancer registry was grouped into three categories: (1) localized cancer: T1-3/N0/M0; (2) cancer with regional metastasis: any 1-3/N+/M0; (3) advanced cancer: any T/any N/M+. Joinpoint regression was used to provide annual percentage changes (APCs) and to detect points in time where statistically significant changes in the trends occurred.

RESULTS

Overall, 8514 pancreatic cancer cases (4364 in men and 3150 in women) were diagnosed and 7684 persons died from cancer of the pancreas. Pancreatic cancer incidence rates were considerably lower for women than for men, with a female:male ratio of 1:2. Incidence rates changed during the study period from 14.2 in 1998 to 15.0/100,000 in the year 2015 in men, and from 6.7 to 9.8/100,000 in women. Incidence rates over the study period were stable for men (APC = 0.1%) and increasing for women by 1.1% per year. Similarly, mortality rates increased in women by 0.9% per year, and were stable in men. During the study period, incidence and mortality rates of pancreatic cancer were close. For the entire study period, rates increased significantly in the 50-74 years age group; only cancer of the head of pancreas showed a decline by 0.9%, while tail and not-specified pancreatic cancer incidence increased by 11.4% and 4.51%, respectively.

CONCLUSIONS

The increasing pancreatic cancer incidence trend in the Lithuanian population may be related to the prevalence of its main risk factors (smoking, obesity, physical inactivity, diet, and diabetes).

Quality Diet Index and Risk of Pancreatic Cancer: Findings from the Singapore Chinese Health Study

BACKGROUND

Limited research has been conducted on the effect of quality diet index (QDI), which represents a comprehensive assessment of healthy diet quality and quantity, on pancreatic cancer risk in Asian populations.

METHODS

Using data from the Singapore Chinese Health Study, a prospective cohort of 63,257 middle-aged or older Chinese men and women, four QDI scores: the Alternative Health Eating Index-2010 (AHEI-2010), the alternate Mediterranean Diet (aMED), the Dietary Approaches to Stop Hypertension (DASH), and the Heathy Diet Indicator (HDI), at baseline were calculated. After 25 years of follow-up, 311 cohort participants developed pancreatic cancer. Cox proportional hazard regression method was used to estimate HR and 95% confidence interval (CI) for pancreatic cancer associated with higher QDI scores.

RESULTS

Higher scores of AHEI-2010, aMED, and DASH were significantly associated with lower pancreatic cancer risk (all P _trend < 0.05). Compared with the lowest quartile, HRs (95% CIs) of pancreatic cancer for the highest quartiles of AHEI-2010, aMED, and DASH scores were 0.65 (0.46-0.90), 0.57 (0.38-0.85), and 0.66 (0.46-0.95), respectively. These associations were more apparent among men. Overall, there was no statistically significant difference in the QDI-pancreatic cancer risk association between subgroups stratified by levels of body mass index, history of diabetes, and smoking status.

CONCLUSIONS

Higher QDI scores were significantly associated with reduced risk of pancreatic cancer.

IMPACT

The consistent results across multiple QDIs shows that adherence to a healthy diet may lower pancreatic cancer risk, suggesting that dietary modification may be a promising approach for primary prevention of pancreatic cancer.

Beneficial Diets and Pancreatic Cancer: Molecular Mechanisms and Clinical Practice

Pancreatic cancer (PC) is a malignant tumor with high invasiveness, easy metastatic ability, and chemoresistance. Patients with PC have an extremely low survival rate due to the difficulty in early diagnosis. It is estimated that nearly 90% of PC cases are caused by environmental risk factors. Approximately 50% of PC cases are induced by an unhealthy diet, which can be avoided. Given this large attribution to diet, numerous studies have assessed the relationship between various dietary factors and PC. This article reviews three beneficial diets: a ketogenic diet (KD), a Mediterranean diet (MD), and a low-sugar diet. Their composition and impact mechanism are summarized and discussed. The associations between these three diets and PC were analyzed, and we aimed to provide more help and new insights for the prevention and treatment of PC.

Pancreatic Cancer Exposome Profile to Aid Early Detection and Inform Prevention Strategies

Pancreatic cancer (PCa) is associated with a poor prognosis and high mortality rate. The causes of PCa are not fully elucidated yet, although certain exposome factors have been identified. The exposome is defined as the sum of all environmental factors influencing the occurrence of a disease during a life span. The development of an exposome approach for PCa has the potential to discover new disease-associated factors to better understand the carcinogenesis of PCa and help with early detection strategies. Our systematic review of the literature identified several exposome factors that have been associated with PCa alone and in combination with other exposures. A potential inflammatory signature has been observed among the interaction of several exposures (i.e., smoking, alcohol consumption, diabetes mellitus, obesity, and inflammatory markers) that further increases the incidence and progression of PCa. A large number of exposures have been identified such as genetic, hormonal, microorganism infections and immune responses that warrant further investigation. Future early detection strategies should utilize this information to assess individuals' risk for PCa.

Red meat consumption, cooking mutagens, NAT1/2 genotypes and pancreatic cancer risk in two ethnically diverse prospective cohorts

There is limited evidence on the association between red meat consumption and pancreatic cancer among ethnic minorities. We assessed this relationship in two large prospective cohorts: the Multiethnic Cohort Study (MEC) and the Southern Community Cohort Study (SCCS). Demographic, dietary and other risk factor data were collected at cohort entry. Red meat intake was assessed using cohort-specific validated food frequency questionnaires. Incident pancreatic cancer cases were identified via linkages to state cancer registries. Cox regression was used to calculate relative risks (RRs) and 95% confidence intervals (CIs) for the association of red meat intake with pancreatic cancer risk in each cohort. We performed additional analyses to evaluate cooking methods, mutagens and effect modification by NAT1/2 genotypes. From a total of 184 542 (MEC) and 66 793 (SCCS) at-risk participants, we identified 1618 (MEC) and 266 (SCCS) incident pancreatic cancer cases. Red meat consumption was associated with pancreatic cancer risk in the MEC (RRQ4vsQ1 1.18, 95% CI 1.02-1.37) and with borderline statistical significance in the SCCS (RRQ4vsQ1 1.31, 95% CI 0.93-1.86). This association was significant in African Americans (RRQ4vsQ1 1.49, 95% CI 1.06-2.11) and Latinos (RRQ4vsQ1 1.44, 95% CI 1.02-2.04) in the MEC, and among African Americans (RRQ4vsQ1 1.55, 95% CI 1.03-2.33) in the SCCS. NAT2 genotypes appeared to modify the relationship between red meat and pancreatic cancer in the MEC (pinteraction = 0.03). Our findings suggest that the associations for red meat may be strongest in African Americans and Latinos. The mechanisms underlying the increased risk for these populations should be further investigated.

Red and processed meat consumption and cancer outcomes: Umbrella review

The purpose of this umbrella review was to evaluate the quality of evidence, validity and biases of the associations between red and processed meat consumption and multiple cancer outcomes according to existing systematic reviews and meta-analyses. The umbrella review identified 72 meta-analyses with 20 unique outcomes for red meat and 19 unique outcomes for processed meat. Red meat consumption was associated with increased risk of overall cancer mortality, non-Hodgkin lymphoma (NHL), bladder, breast, colorectal, endometrial, esophageal, gastric, lung and nasopharyngeal cancer. Processed meat consumption might increase the risk of overall cancer mortality, NHL, bladder, breast, colorectal, esophageal, gastric, nasopharyngeal, oral cavity and oropharynx and prostate cancer. Dose-response analyses revealed that 100 g/d increment of red meat and 50 g/d increment of processed meat consumption were associated with 11%-51% and 8%-72% higher risk of multiple cancer outcomes, respectively, and seemed to be not correlated with any benefit.

Poultry and Fish Intake and Pancreatic Cancer Risk: A Systematic Review and Meta-Analysis

Although several epidemiological studies have investigated associations between poultry and fish consumption and pancreatic cancer (PC) risk, these findings have been inconsistent. The present study aimed to perform a meta-analysis to comprehensively evaluate these associations. We retrieved Eligible cohort studies and case-control studies published before February 2020 from the Medline, EMBASE, and Cochrane Library and applied a random or fixed effects model to calculate the pooled relative risk (RR) and the corresponding 95% confidence intervals (CI). Publication bias was detected using funnel plots, Begg's test, and Egger's test, and the study quality was evaluated using the Newcastle-Ottawa scale. We included 25 studies in the analyses. The pooled RR of PC for the highest vs. lowest poultry intake category was 1.14 (95% CI: 1.02-1.26) in cohort studies. There was no appreciable link between fish intake and PC risk (RR: 1.00, 95% CI: 0.93-1.07). Our results suggest that large amount of poultry intake may increase PC risk, while fish intake is unlikely to be linked to PC risk. These links require further investigation, particularly between poultry and PC.

Biomarkers and Strategy to Detect Preinvasive and Early Pancreatic Cancer: State of the Field and the Impact of the EDRN

Patients afflicted with pancreatic ductal adenocarcinoma (PDAC) face a dismal prognosis, but headway could be made if physicians could identify the disease earlier. A compelling strategy to broaden the use of surveillance for PDAC is to incorporate molecular biomarkers in combination with clinical analysis and imaging tools. This article summarizes the components involved in accomplishing biomarker validation and an analysis of the requirements of molecular biomarkers for disease surveillance. We highlight the significance of consortia for this research and highlight resources and infrastructure of the Early Detection Research Network (EDRN). The EDRN brings together the multifaceted expertise and resources needed for biomarker validation, such as study design, clinical care, biospecimen collection and handling, molecular technologies, and biostatistical analysis, and studies coming out of the EDRN have yielded biomarkers that are moving forward in validation. We close the article with an overview of the current investigational biomarkers, an analysis of their performance relative to the established benchmarks, and an outlook on the current needs in the field. The outlook for improving the early detection of PDAC looks promising, and the pace of further research should be quickened through the resources and expertise of the EDRN and other consortia.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

A Prospective Analysis of Intake of Red and Processed Meat in Relation to Pancreatic Cancer among African American Women

BACKGROUND

African Americans have the highest incidence of pancreatic cancer of any racial/ethnic group in the United States. There is evidence that consumption of red or processed meat and foods containing saturated fats may increase the risk of pancreatic cancer, but there is limited evidence in African Americans.

METHODS

Utilizing the Black Women's Health Study (1995-2018), we prospectively investigated the associations of red and processed meat and saturated fats with incidence of pancreatic adenocarcinoma (n = 168). A food frequency questionnaire was completed by 52,706 participants in 1995 and 2001. Multivariable-adjusted HRs and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression. We observed interactions with age (P _interaction = 0.01). Thus, results were stratified at age 50 (<50, ≥50).

RESULTS

Based on 148 cases among women aged ≥50 years, total red meat intake was associated with a 65% increased pancreatic cancer risk (HR_{Q4 vs. Q1} = 1.65; 95% CI, 0.98-2.78; P _trend = 0.05), primarily due to unprocessed red meat. There was also a nonsignificant association between total saturated fat and pancreatic cancer (HR_{Q4 vs. Q1} = 1.85; 95% CI, 0.92-3.72; P _trend = 0.08). Red meat and saturated fat intakes were not associated with pancreatic cancer risk in younger women, and there was no association with processed meat in either age group.

CONCLUSIONS

Red meat-specifically, unprocessed red meat-and saturated fat intakes were associated with an increased risk of pancreatic cancer in African-American women aged 50 and older, but not among younger women.

IMPACT

The accumulating evidence-including now in African-American women-suggests that diet, a modifiable factor, plays a role in the etiology of pancreatic cancer, suggesting opportunities for prevention.

Meta-analysis of fish consumption and risk of pancreatic cancer in 13 prospective studies with 1.8 million participants

A previous meta-analysis suggested no association between fish consumption and risk of pancreatic cancer. As several prospective studies with a large number of pancreatic cancer cases have emerged after that meta-analysis, we updated the evidence and examined the relationship in greater depth. We performed a literature search on PubMed and EMBASE databases through March 30, 2019 to identify potentially eligible studies. We used a random-effects model to compute summary relative risk (RR) with corresponding 95% confidence interval (CI). A total of 13 prospective studies comprising 4994 pancreatic cancer cases and 1,794,601 participants were included in the final analyses. Results of the meta-analysis showed that fish consumption was not significantly associated with risk of pancreatic cancer (RR 50-g/day = 1.03, 95% CI: 0.95-1.12), which was confirmed when stratifying the analysis by various methodological and population characteristics. There was a suggestion of difference by adjustment for family history of pancreatic cancer (Pdifference = 0.05), with fish consumption being associated with higher risk of pancreatic cancer in studies without adjustment for participants' family history (RR50-g/day = 1.09, 95% CI: 1.02-1.18), and a non-significant inverse association among studies with the adjustment (RR50-g/day = 0.93, 95% CI: 0.82-1.05). Results of this updated meta-analysis suggest that fish consumption is unlikely to be substantially associated with risk of pancreatic cancer.

Vitamin C and Vitamin E Mitigate the Risk of Pancreatic Ductal Adenocarcinoma from Meat-Derived Mutagen Exposure in Adults in a Case-Control Study

BACKGROUND

Previous studies have found that meat-derived mutagens increase, and vitamin C or E decrease, the risk of pancreatic cancer.

OBJECTIVE

The aim of this study was to determine whether intake of vitamin C or E modulates the association between meat-derived mutagen exposure and risk of pancreatic cancer.

DESIGN

We conducted a case-control study in 1321 patients with pathologically confirmed pancreatic ductal adenocarcinoma (PDAC) and 1061 healthy controls (aged 28-88 y). Cases and controls were frequency-matched by age, sex, and race/ethnicity. Mutagen intake was assessed using a meat preparation questionnaire. Intakes of vitamin C, E, and other dietary components were assessed via a food-frequency questionnaire in a subset of 811 cases and 818 controls. ORs and 95% CIs were estimated in multivariable-adjusted logistic regression models.

RESULTS

The risk of PDAC was not associated with meat intake but was associated with consumption of well-done grilled or barbecued chicken (OR: 1.57; 95% CI: 1.18, 2.09; P = 0.001). Intake of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline was associated with increased PDAC risk (Ptrend = 0.047). Participants in the highest, as compared with the lowest, quintile of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (PhIP) intake experienced a 38% increased risk of PDAC (95% CI: 1.00, 1.90; P = 0.048). Intakes of total vitamin C or E from food and supplements or from supplements alone were each inversely associated with PDAC risk. Stratified analyses showed differential associations for PhIP intake and PDAC risk, such that risk increased among individuals with lower intake of vitamin C or E and decreased among those with higher vitamin intake. Significant interactions of dietary vitamin C, dietary vitamin E, and total vitamin E with PhIP intake were detected (Pinteraction = 0.023, <0.001, and 0.013, respectively).

CONCLUSIONS

Consistent with experimental evidence, this study of 811 cases and 818 controls has shown that high intake of dietary vitamin C or E mitigates the risk of PhIP-related PDAC.

Apiaceous Vegetables and Cruciferous Phytochemicals Reduced PhIP-DNA Adducts in Prostate but Not in Pancreas of Wistar Rats

We previously showed rats fed with apiaceous vegetables, but not with their putative chemopreventive phytochemicals, reduced colonic DNA adducts formed by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a dietary procarcinogen. We report here the effects of feeding apiaceous and cruciferous vegetables versus their purified predominant phytochemicals, either alone or combined, on prostate and pancreatic PhIP-DNA adduct formation. In experiment I, male Wistar rats received three supplemented diets: CRU (cruciferous vegetables), API (apiaceous vegetables), and CRU+API (both types of vegetables). In experiment II, rats received three diets supplemented with phytochemicals matched to their levels in the vegetables from experiment I: P + I (phenethyl isothiocyanate and indole-3-carbinol), FC (furanocoumarins; 5-methoxypsoralen, 8-methoxypsoralen, and isopimpinellin), and COMBO (P + I and FC combined). After 6 days of feeding, PhIP was injected (10 mg/kg body weight) and animals were killed on day 7. PhIP-DNA adducts were analyzed by LC-MS/MS. In prostate, PhIP-DNA adducts were reduced by API (33%, P < .05), P + I (45%, P < .001), and COMBO (30%, P < .01). There were no effects observed in pancreas. Our results suggest that fresh vegetables and purified phytochemicals lower PhIP-DNA adducts and may influence cancer risk.

Probabilistic estimates of heterocyclic amines and polycyclic aromatic hydrocarbons concentrations in meats and breads applicable to exposure assessments

Random effect meta-regressions were constructed to estimate concentrations of two heterocyclic amines (HCA) and eight polycyclic aromatic hydrocarbons (PAH) in meat and breads. Eighteen HCA studies and nine PAH studies of food concentration were assembled. Concentration was computed for beef, poultry, pork, and seafood, and bread. Fixed effect predictors included cooking time, form of the food, cooking method, interaction between form and cooking method, temperature at which the food was cooked, fuel of the flame source, percentage of fat, and other elements. Meat type was significant to all HCAs but only three of the PAHs. Cooking method or an interaction between cooking method and food form was significant in all the overall models for each compound, and 80% of models created for stratifications of the data based on meat type. Improvement on compilations such as the Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) database comes from inclusion of additional studies, PAH compounds, more generalizable food categories, more cooking methods (such as smoking), and addition of seafood. Meta-regression allows parameters to be estimated with separation of between-study heterogeneity, and extrapolation of exposures to more foods. Resulting uncertainty estimates are useful in a probabilistic exposure assessment.

Association Between Consumption of Red and Processed Meat and Pancreatic Cancer Risk: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The relationship between consumption of red and processed meat and pancreatic cancer risk is inconclusive. We conducted a systematic review and meta-analysis to analyze this relationship.

METHODS

We performed a systematic search of PubMed, EMBASE, and the Web of Science to identify studies that examined associations between consumption of different kinds of meat with pancreatic cancer and were published through February 2016. By using data from these articles, we associated level of consumption with cancer risk and performed subgroup, meta-regression, and publication bias analyses.

RESULTS

We collected and analyzed data from a total of 28 studies that involved 3,143,777 participants (11,325 consumers of red meat) and 2,904,866 participants (9955 consumers of processed meat). We observed statistically significant differences between consumers and non-consumers of these meats in case-control studies (red meat, P = .02; processed meat, P < .01) but not in cohort studies (red meat, P = .09; processed meat, P = .18). In cohort studies, a 100 g/day increase in red meat consumption was associated with significant increase in risk of pancreatic cancer (P = .01); a 50 g/day increase in processed meat consumption was not associated with significant increase in risk of pancreatic cancer (P = .90). In cohort studies, we observed associations in consumption of red meat by men and pancreatic cancer (P < .01) and consumption of processed meat by men and pancreatic cancer (P < .01) but no associations for women (red meat, P = .61; processed meat, P = .88).

CONCLUSIONS

In a systematic review and meta-analysis, we found case-control but not cohort studies to associate consumption of red and processed meat with risk of pancreatic cancer. However, in cohort studies, consumption of red and processed meat appeared to increase risk of pancreatic cancer in men but not in women.

Nutrients and the Pancreas: An Epigenetic Perspective

Pancreatic cancer is the fourth most common cause of cancer-related deaths with a dismal average five-year survival rate of six percent. Substitutional progress has been made in understanding how pancreatic cancer develops and progresses. Evidence is mounting which demonstrates that diet and nutrition are key factors in carcinogenesis. In particular, diets low in folate and high in fruits, vegetables, red/processed meat, and saturated fat have been identified as pancreatic cancer risk factors with a proposed mechanism involving epigenetic modifications or gene regulation. We review the current literature assessing the correlation between diet, epigenetics, and pancreatic cancer.

Epidemiology of pancreatic cancer

Cancer of the pancreas remains one of the deadliest cancer types. Based on the GLOBOCAN 2012 estimates, pancreatic cancer causes more than 331000 deaths per year, ranking as the seventh leading cause of cancer death in both sexes together. Globally, about 338000 people had pancreatic cancer in 2012, making it the 11th most common cancer. The highest incidence and mortality rates of pancreatic cancer are found in developed countries. Trends for pancreatic cancer incidence and mortality varied considerably in the world. A known cause of pancreatic cancer is tobacco smoking. This risk factor is likely to explain some of the international variations and gender differences. The overall five-year survival rate is about 6% (ranges from 2% to 9%), but this vary very small between developed and developing countries. To date, the causes of pancreatic cancer are still insufficiently known, although certain risk factors have been identified, such as smoking, obesity, genetics, diabetes, diet, inactivity. There are no current screening recommendations for pancreatic cancer, so primary prevention is of utmost importance. A better understanding of the etiology and identifying the risk factors is essential for the primary prevention of this disease.

Environmental risk factors for pancreatic cancer: an update

Pancreatic cancer (PC) is one of the most aggressive diseases. Only 10 % of all PC cases are thought to be due to genetic factors. Here, we analyzed the most recently published case-control association studies, meta-analyses, and cohort studies with the aim to summarize the main environmental factors that could have a role in PC. Among the most dangerous agents involved in the initiation phase, there are the inhalation of cigarette smoke, and the exposure to mutagenic nitrosamines, organ-chlorinated compounds, heavy metals, and ionizing radiations. Moreover, pancreatitis, high doses of alcohol drinking, the body microbial infections, obesity, diabetes, gallstones and/or cholecystectomy, and the accumulation of asbestos fibers seem to play a crucial role in the progression of the disease. However, some of these agents act both as initiators and promoters in pancreatic acinar cells. Protective agents include dietary flavonoids, marine omega-3, vitamin D, fruit, vegetables, and the habit of regular physical activity. The identification of the factors involved in PC initiation and progression could be of help in establishing novel therapeutic approaches by targeting the molecular signaling pathways responsive to these stimuli. Moreover, the identification of these factors could facilitate the development of strategies for an early diagnosis or measures of risk reduction for high-risk people.

Increased Incidence of Second Primary Pancreatic Cancer in Patients with Prior Colorectal Cancer: A Population-Based US Study

BACKGROUND

Identifying high-risk groups for pancreatic cancer (PC) may lead to earlier detection. We determined the risk of subsequent PC among survivors of sporadic colorectal cancer (CRC).

METHODS

We evaluated data from the US Surveillance, Epidemiology, and End Results registry to identify individuals with primary CRC between the years 1973-2006. Standardized incidence ratios (SIRs) and 95 % confidence interval (95 % CI) were calculated to compare the risk of subsequent primary PC in the study cohort to that of the standard population. Analysis was stratified by age at diagnosis of CRC and sex. CRC characteristics were compared among CRC survivors with and without PC. Multivariate sub-hazard ratios were calculated to identify factors associated with subsequent primary PC, using death from non-PC causes as a competing event.

RESULTS

Of the 273,144 patients with first primary CRC, 657 (0.24 %) developed subsequent PC. CRC survivors were more likely to develop PC (SIR 1.22; 95 % CI 1.09-1.35). Mean latency period (time between CRC and PC diagnosis) was 1, 3, and 5 years from index age of CRC 20-49, 50-64, and >65 years, respectively. Multivariate analysis showed CRC survivors >50 years had 3.5-fold, those with right-sided CRC had 1.2-fold, and those with localized and regional CRCs had sixfold and fivefold increased risk of PC, respectively.

CONCLUSION

This study suggests that CRC survivors have an increased risk of developing subsequent PC within 1-5 years. CRC survivors age >50 with localized/regional stage, and right-sided CRC have higher predisposition to PC.

Disposition of the Dietary Mutagen 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline in Healthy and Pancreatic Cancer Compromised Humans

Pancreatic cancer is the fourth leading cause of cancer death in the U.S. Once diagnosed, prognosis is poor with a 5-year survival rate of less than 5%. Exposure to carcinogenic heterocyclic amines (HCAs) derived from cooked meat has been shown to be positively associated with pancreatic cancer risk. To evaluate the processes that determine the carcinogenic potential of HCAs for human pancreas, 14-carbon labeled 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), a putative human carcinogenic HCA found in well-done cooked meat, was administered at a dietary relevant dose to human volunteers diagnosed with pancreatic cancer undergoing partial pancreatectomy and healthy control volunteers. After (14)C-MeIQx exposure, blood and urine were collected for pharmacokinetic and metabolite analysis. MeIQx-DNA adducts levels were quantified by accelerator mass spectrometry from pancreatic tissue excised during surgery from the cancer patient group. Pharmacokinetic analysis of plasma revealed a rapid distribution of MeIQx with a plasma elimination half-life of approximately 3.5 h in 50% of the cancer patients and all of the control volunteers. In 2 of the 4 cancer patients, very low levels of MeIQx were detected in plasma and urine suggesting low absorption from the gut into the plasma. Urinary metabolite analysis revealed five MeIQx metabolites with 2-amino-3-methylimidazo[4,5-f]quinoxaline-8-carboxylic acid being the most abundant accounting for 25%-50% of the recovered 14-carbon/mL urine. There was no discernible difference in metabolite levels between the cancer patient volunteers and the control group. MeIQx-DNA adduct analysis of pancreas and duodenum tissue revealed adduct levels indistinguishable from background levels. Although other meat-derived HCA mutagens have been shown to bind DNA in pancreatic tissue, indicating that exposure to HCAs from cooked meat cannot be discounted as a risk factor for pancreatic cancer, the results from this current study show that exposure to a single dietary dose of MeIQx does not readily form measurable DNA adducts under the conditions of the experiment.

Are meat and heme iron intake associated with pancreatic cancer? Results from the NIH-AARP diet and health cohort

Several studies on pancreatic cancer have reported significant positive associations for intake of red meat but null associations for heme iron. We assessed total, red, white and processed meat intake, meat cooking methods and doneness and heme iron and mutagen intake in relation to pancreatic cancer in the NIH-AARP Diet and Health Study cohort. A total of 322,846 participants (187,265 men and 135,581 women) successfully completed and returned the food frequency questionnaire between 1995 and 1996. After a mean follow-up of 9.2 years (up to 10.17 years), 1,417 individuals (895 men and 522 women) developed exocrine pancreatic cancer. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), and trends were calculated using the median value of each quantile. Models incorporated age as the time metric and were adjusted for smoking history, body mass index, self-reported diabetes and energy-adjusted saturated fat. Pancreatic cancer risk significantly increased with intake of total meat (Q5 vs. Q1: HR = 1.20, 95% CI 1.02-1.42, p-trend = 0.03), red meat (HR = 1.22, 95% CI 1.01-1.48, p-trend = 0.02), high-temperature cooked meat (HR = 1.21, 95% CI 1.00-1.45, p-trend = 0.02), grilled/barbequed meat (HR = 1.24, 95% CI 1.03-1.50, p-trend = 0.007), well/very well done meat (HR = 1.32, 95% CI 1.10-1.58, p-trend = 0.005) and heme iron from red meat (Q4 vs. Q1: HR = 1.21, 95% CI 1.01-1.45, p-trend = 0.04). When stratified by sex, these associations remained significant in men but not women except for white meat intake in women (HR = 1.33, 95% CI 1.02-1.74, p-trend = 0.04). Additional studies should confirm our findings that consuming heme iron from red meat increases pancreatic cancer risk.

Early detection of pancreatic cancer

Pancreatic adenocarcinoma is a low-incident but highly mortal disease. It accounts for only 3% of estimated new cancer cases each year but is currently the fourth common cause of cancer mortality. By 2030, it is expected to be the 2(nd) leading cause of cancer death. There is a clear need to diagnose and classify pancreatic cancer at earlier stages in order to give patients the best chance at a definitive cure through surgery. Three precursor lesions that distinctly lead to pancreatic adenocarcinoma have been identified, and we have increasing understanding the non-genetic and genetic risk factors for the disease. With increased understanding about the risk factors, the familial patters, and associated accumulation of genetic mutations involved in pancreatic cancer, we know that there are mutations that occur early in the development of pancreatic cancer and that improved genetic risk-based strategies in screening for pancreatic cancer may be possible and successful at saving or prolonging lives. The remaining challenge is that current standards for diagnosing pancreatic cancer remain too invasive and too costly for widespread screening for pancreatic cancer. Furthermore, the promises of noninvasive methods of detection such as blood, saliva, and stool remain underdeveloped or lack robust testing. However, significant progress has been made, and we are drawing closer to a strategy for the screening and early detection of pancreatic cancer.

Gene-by-Environment Interactions in Pancreatic Cancer: Implications for Prevention

Pancreatic cancer (PC) has been estimated to have higher incidence and correspondingly higher mortality rates in more developed regions worldwide. Overall, the age-adjusted incidence rate is 4.9/10(5) and age-adjusted mortality rate is at 4.8/10(5). We review here our current knowledge of modifiable risk factors (cigarette smoking, obesity, diet, and alcohol) for PC, genetic variants implicated by genome-wide association studies, possible genetic interactions with risk factors, and prevention strategies to provide future research directions that may further our understanding of this complex disease. Cigarette smoking is consistently associated with a two-fold increased PC risk. PC associations with dietary intake have been largely inconsistent, with the potential exception of certain unsaturated fatty acids decreasing risk and well-done red meat or meat mutagens increasing risk. There is strong evidence to support that obesity (and related measures) increase risk of PC. Only the heaviest alcohol drinkers seem to be at an increased risk of PC. Currently, key prevention strategies include avoiding tobacco and excessive alcohol consumption and adopting a healthy lifestyle. Screening technologies and PC chemoprevention are likely to become more sophisticated, but may only apply to those at high risk. Risk stratification may be improved by taking into account gene environment interactions. Research on these modifiable risk factors is key to reducing the incidence of PC and understanding who in the population can be considered high risk.

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.

Meat, dairy, and cancer

In 2007 the World Cancer Research Fund and American Institute for Cancer Research (WCRF/AICR) report judged that the evidence for an association between red and processed meat consumption and colorectal cancer was convincing. In addition, the effect of other animal products on cancer risk has been studied, and the WCRF/AICR report concluded that milk probably decreases the risk of colorectal cancer but diets high in calcium probably increase the risk of prostate cancer, whereas there was limited evidence for an association between milk and bladder cancer and insufficient evidence for other cancers. There are several potential mechanisms relating meat to cancer, including heterocyclic amines, polycyclic aromatic hydrocarbons, N-nitroso compounds, and heme iron. Although the evidence in favor of a link between red and processed meat and colorectal cancer is convincing, the relations with other cancers are unclear. In this review, we summarize cohort studies conducted by the National Cancer Institute on meat and dairy intake in relation to cancer since the 2007 WCRF/AICR report. We also report the findings of meta-analyses published since 2007.

Fatty acids found in dairy, protein and unsaturated fatty acids are associated with risk of pancreatic cancer in a case-control study

Although many studies have investigated meat and total fat in relation to pancreatic cancer risk, few have investigated dairy, fish and specific fatty acids (FAs). We evaluated the association between intake of meat, fish, dairy, specific FAs and related nutrients and pancreatic cancer. In our American-based Mayo Clinic case-control study 384 cases and 983 controls frequency matched on recruitment age, race, sex and residence area (Minnesota, Wisconsin or Iowa, USA) between 2004 and 2009. All subjects provided demographic information and completed 144-item food frequency questionnaire. Logistic regression-calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) were adjusted for age, sex, cigarette smoking, body mass index and diabetes mellitus. Significant inverse association (trend p-value < 0.05) between pancreatic cancer and the groupings (highest vs. lowest consumption quintile OR [95% CI]) was as follows: meat replacement (0.67 [0.43-1.02]), total protein (0.58 [0.39-0.86]), vitamin B12 (0.67 [0.44, 1.01]), zinc (0.48 [0.32, 0.71]), phosphorus (0.62 [0.41, 0.93]), vitamin E (0.51 [0.33, 0.78]), polyunsaturated FAs (0.64 [0.42, 0.98]) and linoleic acid (FA 18:2) (0.62 [0.40-0.95]). Increased risk associations were observed for saturated FAs (1.48 [0.97-2.23]), butyric acid (FA 4:0) (1.77 [1.19-2.64]), caproic acid (FA 6:0) (2.15 [1.42-3.27]), caprylic acid (FA 8:0) (1.87 [1.27-2.76]) and capric acid (FA 10:0) (1.83 [1.23-2.74]). Our study suggests that eating a diet high in total protein and certain unsaturated FAs is associated with decreased risk of developing pancreatic cancer in a dose-dependent manner, whereas fats found in dairy increase risk.

Pancreatic cancer death rates by race among US men and women, 1970-2009

BACKGROUND

Few studies have examined trends in pancreatic cancer death rates in the United States, and there have been no studies examining recent trends using age-period-cohort analysis.

METHODS

Annual percentage change in pancreatic cancer death rates was calculated for 1970 to 2009 by sex and race among adults aged 35 to 84 years using US mortality data provided by the National Center for Health Statistics and Joinpoint Regression. Age-period-cohort modeling was performed to evaluate the changes in cohort and period effects. All statistical tests were two-sided.

RESULTS

In white men, pancreatic cancer death rates decreased by 0.7% per year from 1970 to 1995 and then increased by 0.4% per year through 2009. Among white women, rates increased slightly from 1970 to 1984, stabilized until the late 1990s, then increased by 0.5% per year through 2009. In contrast, the rates among blacks increased between 1970 and the late 1980s (women) or early 1990s (men) and then decreased thereafter. Age-period-cohort analysis showed that pancreatic cancer death risk was highest for the 1900 to 1910 birth cohort in men and the 1920 to 1930 birth cohort in women and there was a statistically significant increase in period effects since the late 1990s in both white men and white women (two-sided Wald test, P < .001).

CONCLUSIONS

In the United States, whites and blacks experienced opposite trends in pancreatic cancer death rates between 1970 and 2009 that are largely unexplainable by known risk factors. This study underscores the needs for urgent action to curb the increasing trends of pancreatic cancer in whites and for better understanding of the etiology of this disease.

The role of Mediterranean diet on the risk of pancreatic cancer

Background:

The Mediterranean diet has been shown to have a beneficial role on various neoplasms, but data are scanty on pancreatic cancer.

Methods:

We analysed data from two case–control studies conducted in Italy between 1983 and 2008, including 362 and 326 pancreatic cancer cases and 1552 and 652 hospital-controls, respectively. A Mediterranean Diet Score (MDS) summarising major characteristics of the Mediterranean diet was used in the two studies separately and overall. Two further scores of adherence to the Mediterranean diet were applied in the second study only, the Mediterranean Dietary Pattern Adherence Index (MDP) and the Mediterranean Adequacy Index (MAI).

Results:

Odds ratios (ORs) for increasing levels of the scores (i.e., increasing adherence) were estimated using multiple logistic regression models. Odds ratio for a MDS score ⩾6 compared with <3 was 0.57 (95% confidence interval (CI) 0.34–0.95) in the first study, 0.51 (95% CI 0.29–0.92) in the second study, and 0.48 (95% CI 0.35–0.67) overall. A trend of decreasing risk was observed also for the MDP and MAI the ORs for the highest vs the lowest quintile being 0.44 (95% CI 0.27–0.73) for MDP and 0.68 (95% CI 0.42–1.11) for the MAI. The results were consistent across strata of age, sex, education, body mass index, alcohol drinking, tobacco smoking, and diabetes.

Conclusion:

Our study provides evidence that a priori-defined scores measuring adherence to the Mediterranean diet are favourably associated with pancreatic cancer risk.

Meat-related mutagens and pancreatic cancer: null results from a clinic-based case-control study

BACKGROUND

Pancreatic cancer is a devastating disease for which the role of dietary factors remains inconclusive. The study objective was to evaluate risk of pancreatic cancer associated with meat preparation methods and meat-related mutagen consumption using a clinic-based case-control design.

METHODS

There were 384 cases and 983 controls; subjects provided demographic information and completed a 144-item food frequency questionnaire, which was used to estimate meat mutagen intake using the National Cancer Institute's CHARRED database (Bethesda, MD). Logistic regression was used to calculate ORs and 95% confidence intervals (CI), adjusted for factors including age, sex, cigarette smoking, body mass index, and diabetes mellitus.

RESULTS

Overall, the findings were null with respect to meat mutagen intake and pancreatic cancer.

CONCLUSIONS

The results do not support an association between well-done meat or meat-related mutagen intake and pancreatic cancer and contrast with generally increased risks reported in previous studies.

IMPACT

These data contribute to evidence about pancreatic cancer and potentially carcinogenic compounds in meat.

Nutrient-based dietary patterns and pancreatic cancer risk

PURPOSE

Few data are available on the role of combinations of foods and/or nutrients on pancreatic cancer risk. To add further information on dietary patterns potentially associated to pancreatic cancer, we applied an exploratory principal component factor analysis on 28 major nutrients derived from an Italian case-control study.

METHODS

Cases were 326 incident pancreatic cancer cases and controls 652 frequency-matched controls admitted to hospital for non-neoplastic diseases. Dietary information was collected through a validated and reproducible food frequency questionnaire. Multiple logistic regression models adjusted for sociodemographic variables and major recognized risk factors for pancreatic cancer were used to estimate the odds ratios (OR) of pancreatic cancer for each dietary pattern.

RESULTS

We identified four dietary patterns-named "animal products," "unsaturated fats," "vitamins and fiber," and "starch rich," that explain 75% of the total variance in nutrient intake in this population. After allowing for all the four patterns, positive associations were found for the animal products and the starch rich patterns, the OR for the highest versus the lowest quartiles being 2.03 (95% confidence interval [CI], 1.29-3.19) and 1.69 (95% CI, 1.02-2.79), respectively; an inverse association emerged for the vitamins and fiber pattern (OR, 0.55; 95% CI, 0.35-0.86), whereas no association was observed for the unsaturated fats pattern (OR, 1.13; 95% CI, 0.71-1.78).

CONCLUSIONS

A diet characterized by a high consumption of meat and other animal products, as well as of (refined) cereals and sugars, is positively associated with pancreatic cancer risk, whereas a diet rich in fruit and vegetables is inversely associated.

Oral benzo[a]pyrene in Cyp1a1/1b1(-/-) double-knockout mice: Microarray analysis during squamous cell carcinoma formation in preputial gland duct

Benzo[a]pyrene (BaP) is a prototypical polycyclic aromatic hydrocarbon (PAH) found in combustion processes. Cytochrome P450 1A1 and 1B1 enzymes (CYP1A1, CYP1B1) and other enzymes can activate PAHs to reactive oxygenated intermediates involved in mutagenesis and tumor initiation; also, CYP1 enzymes can detoxify PAHs. Cyp1(+/+) wild-type (WT) and Cyp1b1(-/-) knockout mice receiving oral BaP (12.5 mg/kg/day) remain healthy for >12 months. In contrast, we found that global knockout of the Cyp1a1 gene (1a1KO) results in proximal small intestine (PSI) adenocarcinoma within 8-12 weeks on this BaP regimen; striking compensatory increases in PSI CYP1B1 likely participate in initiation of adenocarcinoma in 1a1KO mice. Cyp1a1/1b1(-/-) double-knockout (DKO) mice on this BaP regimen show no PSI adenocarcinoma, but instead preputial gland duct (PGD) squamous cell carcinoma (SCC) occurs by 12 weeks. Herein, we compare microarray expression of PGD genes in WT, 1a1KO and DKO mice at 0, 4, 8, 12 and 16 weeks of oral BaP; about four dozen genes up- or down-regulated during most critical time-points were further verified by qRT-PCR. In DKO mice, CYP3A59 was unequivocally identified as the BaP-inducible and BaP-metabolizing best candidate responsible for initiation of BaP-induced SCC. Striking increases or decreases were found in 26 cancer-related genes plus eight Serpin genes in DKO, but not in 1a1KO or WT, mice on this BaP regimen; of the 26, 8 were RAS-related oncogenes. The mechanism by which cancer-related genes are responsible for SCC tumor progression in the PGD remains to be elucidated.

Meat and fish consumption and risk of pancreatic cancer: results from the European Prospective Investigation into Cancer and Nutrition

Pancreatic cancer is the fourth most common cause of cancer death worldwide with large geographical variation, which implies the contribution of diet and lifestyle in its etiology. We examined the association of meat and fish consumption with risk of pancreatic cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC). A total of 477,202 EPIC participants from 10 European countries recruited between 1992 and 2000 were included in our analysis. Until 2008, 865 nonendocrine pancreatic cancer cases have been observed. Calibrated relative risks (RRs) and 95% confidence intervals (CIs) were computed using multivariable-adjusted Cox hazard regression models. The consumption of red meat (RR per 50 g increase per day = 1.03, 95% CI = 0.93-1.14) and processed meat (RR per 50 g increase per day = 0.93, 95% CI = 0.71-1.23) were not associated with an increased pancreatic cancer risk. Poultry consumption tended to be associated with an increased pancreatic cancer risk (RR per 50 g increase per day = 1.72, 95% CI = 1.04-2.84); however, there was no association with fish consumption (RR per 50 g increase per day = 1.22, 95% CI = 0.92-1.62). Our results do not support the conclusion of the World Cancer Research Fund that red or processed meat consumption may possibly increase the risk of pancreatic cancer. The positive association of poultry consumption with pancreatic cancer might be a chance finding as it contradicts most previous findings.