Cigarette smoking and pancreas cancer: a case control study of the search programme of the IARC

Earlier Diagnosis of Pancreatic Cancer: Is It Possible?

Pancreatic ductal adenocarcinoma has a very high mortality rate which has been only minimally improved in the last 30 years. This high mortality is closely related to late diagnosis, which is usually made when the tumor is large and has extensively infiltrated neighboring tissues or distant metastases are already present. This is a paradoxical situation for a tumor that requires nearly 15 years to develop since the first founding mutation. Response to chemotherapy under such late circumstances is poor, resistance is frequent, and prolongation of survival is almost negligible. Early surgery has been, and still is, the only approach with a slightly better outcome. Unfortunately, the relapse percentage after surgery is still very high. In fact, early surgery clearly requires early diagnosis. Despite all the advances in diagnostic methods, the available tools for improving these results are scarce. Serum tumor markers permit a late diagnosis, but their contribution to an improved therapeutic result is very limited. On the other hand, effective screening methods for high-risk populations have not been fully developed as yet. This paper discusses the difficulties of early diagnosis, evaluates whether the available diagnostic tools are adequate, and proposes some simple and not-so-simple measures to improve it.

The Diverse Involvement of Cigarette Smoking in Pancreatic Cancer Development and Prognosis

Despite extensive research in the pathogenesis, early detection, and therapeutic approaches of pancreatic ductal adenocarcinoma (PDAC), it remains a devastating and incurable disease. As the global incidence and prevalence of PDAC continue to rise, there is a pressing need to place strong emphasis on its prevention. Although it is widely recognized that cigarette smoking, a potentially modifiable risk factor, has been linked to PDAC development, its contribution to prognosis is still uncertain. Moreover, the mechanistic pathways of PDAC progression secondary to smoking are various and lack a summative narration. Herein, we update and summarize the direct and indirect roles cigarette smoking plays on PDAC development, review literature to conclude the impact cigarette smoking has on prognosis, and postulate a comprehensive mechanism for cigarette smoking-induced PDAC.

THE CHANGING TREND OF MORTALITY CAUSED BY GASTROINTESTINAL CANCERS IN IRAN DURING THE YEARS 2006-2010

BACKGROUND

Cancers are one of the most important causes of death in the world. According to their high incidence and mortality, gastrointestinal cancers have particular importance among other cancers.

OBJECTIVE

Therefore, this study was conducted to investigate the mortality change trends of gastrointestinal cancers in Iran.

METHODS

This study was performed by analyzing the reported mortality data in 29 provinces of Iran in 2006-2010. Mortality trend of gastrointestinal cancers was drawn for both sexes in the study years and disaggregated by age groups and their frequency distribution. The WinPepi software was used for analysis.

RESULTS

In the years 2006-2010, the mortality rate of, gastric, colorectal, liver and pancreatic cancers, has significantly increased. Totally, gastrointestinal mortality is higher in men than women. Also, the results showed that by increasing age, death from these cancers also increased.

CONCLUSION

The most important causes of death from gastrointestinal cancers were gastric, liver and colorectal cancers in Iran and because of their increasing trend in the country, performing preventive interventions for the cancers' risk factors is necessary.

Pancreatic damage induced by cigarette smoke: the specific pathological effects of cigarette smoke in the rat model

In recent years, pancreatic pathologies have become common problems and their etiology and pathogenesis are generally unknown. Studies have shown that smoking may increase the risk of pancreatic disorders but very scant knowledge is available about the pathogenesis of cigarette induced pancreatic pathology. This study aimed to evaluate the oxidative stress status, biochemical, pathological and immunohistochemical findings of rats exposed to cigarette smoke, pathogenesis of smoking related pancreatic damage and usability of Alpha Lipoic Acid (ALA) for amelioration of cigarette smoking induced harmful effects on rat pancreas. Twenty eight female, Sprague Dawley rats were randomly distributed into three groups. The sham group (S) (n = 8), rats were given 0.1 ml of physiological serum by oral gavage for 8 weeks. The cigarette smoke exposed group (CSE) (n = 10), rats were exposed to successive periods of cigarette smoke for 2 hours per day per 8 weeks and given 0.1 ml of physiological serum orally during the study. The cigarette smoke exposed and ALA treated group (CSE + ALA) (n = 10), animals were exposed to cigarette smoke (2 hours per day per 8 weeks) and simultaneously treated with 100 mg per kg per day ALA orally during the study. At the end of the study, the serum samples were collected for insulin, glucagon, glucose and amylase analyses. Tissue samples were collected for biochemical, histopathological and immunohistochemical examinations. Total oxidant status (TOS), total antioxidant status (TAS) levels and oxidative stress index (OSI) were evaluated in the pancreas samples. Immunohistochemical analyses of insulin, glucagon, calcitonin gene related protein (CGRP), active caspase-3, hypoxia inducible factor-1 (Hif-1), Hif-2 and tumor necrosis factor (TNF-α) expressions of pancreas were examined. Cigarette smoke caused statistically significant increase in serum amylase and glucose but decreased insulin levels indicating both endocrine and exocrine cell damage. There were no statistically significant differences in serum glucagon levels between the groups. Histopathological examination of the pancreas exhibited generally normal tissue architecture but slightly degenerative and apoptotic cells were noticed both in the endocrine and exocrine part of the pancreas in the CSE group. Immunohistochemical analyses revealed marked increase in active caspase-3, Hif-1 and Hif-2, CGRP and TNF-α expressions with a slight increase in glucagon immunoreactivity in cells while a marked decrease was observed in insulin expression in some Langerhans islets in the CSE group. ALA ameliorated biochemical and pathological findings in the CSE + ALA group. These findings clearly demonstrated that cigarette smoke can cause damage in both endocrine and exocrine cells in rat pancreas and ALA has an ameliorative effect of cigarette induced lesions.

Inhibition of renalase expression and signaling has antitumor activity in pancreatic cancer

An essential feature of cancer is dysregulation of cell senescence and death. Renalase, a recently discovered secreted flavoprotein, provides cytoprotection against ischemic and toxic cellular injury by signaling through the PI3K-AKT and MAPK pathways. Here we show that renalase expression is increased in pancreatic cancer tissue and that it functions as a growth factor. In a cohort of patients with pancreatic ductal adenocarcinoma, overall survival was inversely correlated with renalase expression in the tumor mass, suggesting a pathogenic role for renalase. Inhibition of renalase signaling using siRNA or inhibitory anti-renalase antibodies decreased the viability of cultured pancreatic ductal adenocarcinoma cells. In two xenograft mouse models, either the renalase monoclonal antibody m28-RNLS or shRNA knockdown of renalase inhibited pancreatic ductal adenocarcinoma growth. Inhibition of renalase caused tumor cell apoptosis and cell cycle arrest. These results reveal a previously unrecognized role for the renalase in cancer: its expression may serve as a prognostic maker and its inhibition may provide an attractive therapeutic target in pancreatic cancer.

Risk Factors for Early-Onset and Very-Early-Onset Pancreatic Adenocarcinoma: A Pancreatic Cancer Case-Control Consortium (PanC4) Analysis

OBJECTIVES

While pancreatic cancer (PC) most often affects older adults, to date, there has been no comprehensive assessment of risk factors among PC patients younger than 60 years.

METHODS

We defined early-onset PC (EOPC) and very-early-onset PC (VEOPC) as diagnosis of PC in patients younger than 60 and 45 years, respectively. We pooled data from 8 case-control studies, including 1954 patients with EOPC and 3278 age- and sex-matched control subjects. Logistic regression analysis was performed to identify associations with EOPC and VEOPC.

RESULTS

Family history of PC, diabetes mellitus, smoking, obesity, and pancreatitis were associated with EOPC. Alcohol use equal to or greater than 26 g daily also was associated with increased risk of EOPC (odds ratio, 1.49; 95% confidence interval, 1.21-1.84), and there appeared to be a dose- and age-dependent effect of alcohol on risk. The point estimate for risk of VEOPC was an odds ratio of 2.18 (95% confidence interval, 1.17-4.09).

CONCLUSIONS

The established risk factors for PC, including smoking, diabetes, family history of PC, and obesity, also apply to EOPC. Alcohol intake appeared to have an age-dependent effect; the strongest association was with VEOPC.

Online survival analysis software to assess the prognostic value of biomarkers using transcriptomic data in non-small-cell lung cancer

In the last decade, optimized treatment for non-small cell lung cancer had lead to improved prognosis, but the overall survival is still very short. To further understand the molecular basis of the disease we have to identify biomarkers related to survival. Here we present the development of an online tool suitable for the real-time meta-analysis of published lung cancer microarray datasets to identify biomarkers related to survival. We searched the caBIG, GEO and TCGA repositories to identify samples with published gene expression data and survival information. Univariate and multivariate Cox regression analysis, Kaplan-Meier survival plot with hazard ratio and logrank P value are calculated and plotted in R. The complete analysis tool can be accessed online at: www.kmplot.com/lung. All together 1,715 samples of ten independent datasets were integrated into the system. As a demonstration, we used the tool to validate 21 previously published survival associated biomarkers. Of these, survival was best predicted by CDK1 (p<1E-16), CD24 (p<1E-16) and CADM1 (p = 7E-12) in adenocarcinomas and by CCNE1 (p = 2.3E-09) and VEGF (p = 3.3E-10) in all NSCLC patients. Additional genes significantly correlated to survival include RAD51, CDKN2A, OPN, EZH2, ANXA3, ADAM28 and ERCC1. In summary, we established an integrated database and an online tool capable of uni- and multivariate analysis for in silico validation of new biomarker candidates in non-small cell lung cancer.

Ulcer, gastric surgery and pancreatic cancer risk: an analysis from the International Pancreatic Cancer Case-Control Consortium (PanC4)

BACKGROUND

Peptic ulcer and its treatments have been associated to pancreatic cancer risk, although the evidence is inconsistent.

METHODS

We pooled 10 case-control studies within the Pancreatic Cancer Case-control Consortium (PanC4), including 4717 pancreatic cancer cases and 9374 controls, and estimated summary odds ratios (OR) using multivariable logistic regression models.

RESULTS

The OR for pancreatic cancer was 1.10 [95% confidence interval (CI) 0.98-1.23] for history of ulcer (OR = 1.08 for gastric and 0.97 for duodenal ulcer). The association was stronger for a diagnosis within 2 years before cancer diagnosis (OR = 2.43 for peptic, 1.75 for gastric, and 1.98 for duodenal ulcer). The OR was 1.53 (95% CI 1.15-2.03) for history of gastrectomy; however, the excess risk was limited to a gastrectomy within 2 years before cancer diagnosis (OR = 6.18, 95% CI 1.82-20.96), while no significant increased risk was observed for longer time since gastrectomy. No associations were observed for pharmacological treatments for ulcer, such as antacids, H2-receptor antagonists, or proton-pump inhibitors.

CONCLUSIONS

This uniquely large collaborative study does not support the hypothesis that peptic ulcer and its treatment materially affect pancreatic cancer risk. The increased risk for short-term history of ulcer and gastrectomy suggests that any such association is due to increased cancer surveillance.

Survival is associated with genetic variation in inflammatory pathway genes among patients with resected and unresected pancreatic cancer

OBJECTIVE

To test whether or not the association between inflammation and pancreatic ductal adenocarcinoma (PC) is facilitated by host susceptibility, specifically by genetic polymorphisms in inflammation-related genes.

SUMMARY BACKGROUND DATA

Inflammation has been linked to PC. Reports have cited an increased expression of proinflammatory mediators, such as NF-κB and COX, in PC but not in normal adjacent tissue, suggesting a possible role in carcinogenesis. We sought to further understand the role that genetic variants in the NF-κB inflammatory pathway play in the development and progression of PC.

METHODS

We genotyped 1536 tag single nucleotide polymorphisms (SNPs) in 102 candidate genes of multiple inflammatory pathways in 1308 white patients with PC who were divided into 3 groups on the basis of the extent of disease: resected for cure (n = 400), locally advanced/unresected (n = 443), and metastatic (n = 465). Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards regression models. Statistical significance was set at less than 0.001 to control for multiple testing.

RESULTS

Median age was 67 (28.0-91.0) years, and 57% were men. Median survival for each of the 3 groups (resected, locally advanced, and metastatic) was 23.7, 9.4, and 6.6 months, respectively (P < 0.0001). In the resected group, carriers of a minor allele for either rs3824872 (MAPK8IP1) or rs8064821 (SOCS3) were associated with a 10- and 6-month survival advantage compared with noncarriers in patients with resected disease, with an additional 2-year survival if both minor alleles were present. With locally advanced disease, SNP rs1124736 (IGF1R) was associated with improved survival if they had a copy of the G allele, hazard ratio of 0.57 (95% confidence interval: 0.42-0.77); P = 0.0002. In addition, 4 SNPs in patients with metastatic disease were found to be associated with worse survival and 2 associated with improved overall survival, but the differences in survival were deemed not clinically significant.

CONCLUSIONS

SNPs in the inflammatory pathway genes MAPK8IP1 and SOCS3 were associated with increased overall survival in patients undergoing potentially curative resection and may be used in the future as markers to predict survival. Future research is needed to determine the functional relevance of these loci.

Familial melanoma: clinical factors associated with germline CDKN2A mutations according to the number of patients affected by melanoma in a family

BACKGROUND

Features associated with an increased frequency of cyclin-dependent kinase inhibitor 2A (CDKN2A) mutations have been identified in families with 3 or more patients with cutaneous melanoma (CM). However, in families with 2 patients with CM, which represent the majority of familial melanoma, these factors have been rarely studied.

OBJECTIVE

We investigated association of 3 clinical features with the presence of a CDKN2A mutation in a family by extent of CM family clustering (2 vs ≥3 patients with CM among first-degree relatives in a family).

METHODS

We included 483 French families that comprised 387 families with 2 patients with CM (F2 families) and 96 families with 3 or more patients with CM (F3+ families). Three clinical factors were examined individually and in a joint analysis: median age at diagnosis younger than 50 years, and 1 or more patient in a family with multiple primary melanoma or with pancreatic cancer.

RESULTS

The frequency of CDKN2A mutations was higher in F3+ families (32%) than in F2 families (13%). Although early age at melanoma diagnosis and occurrence of multiple primary melanoma in 1 or more patient were significantly associated with the risk of a CDKN2A mutation in F2 families, early age at melanoma diagnosis and occurrence of pancreatic cancer in a family were significantly associated with CDKN2A mutations in F3+ families.

LIMITATIONS

The study was not population based.

CONCLUSIONS

This study shows that factors associated with CDKN2A mutations differ by extent of CM family clustering. It indicates that, in France, families with 2 patients with CM are eligible for genetic testing especially when there is an early age at CM diagnosis and/or 1 or more patients with multiple primary melanoma.

Cigarette smoking and pancreatic cancer: an analysis from the International Pancreatic Cancer Case-Control Consortium (Panc4)

BACKGROUND

To evaluate the dose-response relationship between cigarette smoking and pancreatic cancer and to examine the effects of temporal variables.

METHODS

We analyzed data from 12 case-control studies within the International Pancreatic Cancer Case-Control Consortium (PanC4), including 6507 pancreatic cases and 12 890 controls. We estimated summary odds ratios (ORs) by pooling study-specific ORs using random-effects models.

RESULTS

Compared with never smokers, the OR was 1.2 (95% confidence interval [CI] 1.0-1.3) for former smokers and 2.2 (95% CI 1.7-2.8) for current cigarette smokers, with a significant increasing trend in risk with increasing number of cigarettes among current smokers (OR=3.4 for ≥35 cigarettes per day, P for trend<0.0001). Risk increased in relation to duration of cigarette smoking up to 40 years of smoking (OR=2.4). No trend in risk was observed for age at starting cigarette smoking, whereas risk decreased with increasing time since cigarette cessation, the OR being 0.98 after 20 years.

CONCLUSIONS

This uniquely large pooled analysis confirms that current cigarette smoking is associated with a twofold increased risk of pancreatic cancer and that the risk increases with the number of cigarettes smoked and duration of smoking. Risk of pancreatic cancer reaches the level of never smokers ∼20 years after quitting.

Factors influencing receptivity to future screening options for pancreatic cancer in those with and without pancreatic cancer family history

Background

Pancreatic cancer (PC) is considered the most lethal cancer and approximately 10% of PC is hereditary. The purpose of the study was to assess attitudes of at-risk family members with two or more relatives affected with pancreas cancer (PC) toward PC risk and future screening options.

Methods

At-risk family members and primary care controls were surveyed regarding perceived PC risk, PC worry/concern, attitude toward cancer screening, screening test accuracy, and intentions regarding PC screening via blood testing or more invasive endoscopic ultrasound (EUS).

Results

PC family members reported greater perceived risk of PC than controls (54% vs. 6%, respectively, p < 0.0001). PC family members also reported higher levels of PC worry/concern than controls (p < 0.0001), although 19% of PC family members indicated they were “not at all concerned” about getting PC. PC family members indicated greater acceptance of a false-negative result on a PC screening test relative to controls (12% vs. 8%, p = 0.02). Both groups reported high (>89%) receptivity to the potential PC screening options presented, though receptivity was greater among PC family members as compared to controls (p < 0.0001) for EUS. In multivariable analyses, degree of PC concern (p < 0.0001) was associated with intention to screen for PC by blood test and EUS, while perceived PC risk was associated with likelihood of undergoing EUS only (p < 0.0001).

Conclusions

Receptivity to screening options for PC appears high. Clinicians should address behavioral and genetic risk factors for PC and foster appropriate concern regarding PC risk among at-risk individuals.

Interplay between smoking-induced genotoxicity and altered signaling in pancreatic carcinogenesis

Despite continuous research efforts directed at early diagnosis and treatment of pancreatic cancer (PC), the status of patients affected by this deadly malignancy remains dismal. Its notoriety with regard to lack of early diagnosis and resistance to the current chemotherapeutics is due to accumulating signaling abnormalities. Hoarding experimental and epidemiological evidences have established a direct correlation between cigarette smoking and PC risk. The cancer initiating/promoting nature of cigarette smoke can be attributed to its various constituents including nicotine, which is the major psychoactive component, and several other toxic constituents, such as nitrosamines, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and polycyclic aromatic hydrocarbons. These predominant smoke-constituents initiate a series of oncogenic events facilitating epigenetic alterations, self-sufficiency in growth signals, evasion of apoptosis, sustained angiogenesis, and metastasis. A better understanding of the molecular mechanisms underpinning these events is crucial for the prevention and therapeutic intervention against PC. This review presents various interconnected signal transduction cascades, the smoking-mediated genotoxicity, and genetic polymorphisms influencing the susceptibility for smoking-mediated PC development by modulating pivotal biological aspects such as cell defense/tumor suppression, inflammation, DNA repair, as well as tobacco-carcinogen metabolization. Additionally, it provides a large perspective toward tumor biology and the therapeutic approaches against PC by targeting one or several steps of smoking-mediated signaling cascades.

Nicotine/cigarette smoke promotes metastasis of pancreatic cancer through α7nAChR-mediated MUC4 upregulation

Despite evidence that long-term smoking is the leading risk factor for pancreatic malignancies, the underlying mechanism(s) for cigarette-smoke (CS)-induced pancreatic cancer (PC) pathogenesis has not been well-established. Our previous studies revealed an aberrant expression of the MUC4 mucin in PC as compared to the normal pancreas and its association with cancer progression and metastasis. Interestingly, here we explore a potential link between MUC4 expression and smoking-mediated PC pathogenesis and report that both cigarette-smoke-extract (CSE) and nicotine, which is the major component of CS, significantly up-regulates MUC4 in PC cells. This nicotine-mediated MUC4 overexpression was via α7 subunit of nicotinic acetylcholine receptor (nAChR) stimulation and subsequent activation of the JAK2/STAT3 downstream signaling cascade in cooperation with the MEK/ERK1/2 pathway; this effect was blocked by the α7nAChR antagonists, α-bungarotoxin and mecamylamine, and by specific siRNA-mediated STAT3 inhibition. Additionally, we demonstrated that nicotine-mediated MUC4 up-regulation promotes the PC cell migration through the activation of the downstream effectors such as HER2, c-Src and FAK; this effect was attenuated by shRNA-mediated MUC4 abrogation, further implying that these nicotine-mediated pathological effects on PC cells are MUC4 dependent. Furthermore, the in-vivo studies demonstrated a dramatic increase in the mean pancreatic tumor weight [low-dose (100 mg/m³ TSP), p=0.014; high-dose (247 mg/m³ TSP), p=0.02] and significant tumor metastasis to various distant organs in the CS-exposed-mice, orthotopically implanted with luciferase-transfected PC cells, as compared to the sham-controls. Moreover, the CS-exposed mice had elevated levels of serum cotinine [low-dose, 155.88±35.96 ng/ml; high-dose, 216.25±29.95 ng/ml] and increased MUC4, α7nAChR and pSTAT3 expression in the pancreatic tumor tissues. Altogether, our findings revealed for the first time that CS up-regulates the MUC4 mucin in PC via α7nAChR/JAK2/STAT3 downstream signaling cascade, thereby promoting metastasis of pancreatic cancer.

Alcohol consumption and pancreatic cancer: a pooled analysis in the International Pancreatic Cancer Case-Control Consortium (PanC4)

BACKGROUND

Heavy alcohol drinking has been related to pancreatic cancer, but the issue is still unsolved.

METHODS

To evaluate the role of alcohol consumption in relation to pancreatic cancer, we conducted a pooled analysis of 10 case-control studies (5585 cases and 11,827 controls) participating in the International Pancreatic Cancer Case-Control Consortium. We computed pooled odds ratios (ORs) by estimating study-specific ORs adjusted for selected covariates and pooling them using random effects models.

RESULTS

Compared with abstainers and occasional drinkers (< 1 drink per day), we observed no association for light-to-moderate alcohol consumption (≤ 4 drinks per day) and pancreatic cancer risk; however, associations were above unity for higher consumption levels (OR = 1.6, 95% confidence interval 1.2-2.2 for subjects drinking ≥ 9 drinks per day). Results did not change substantially when we evaluated associations by tobacco smoking status, or when we excluded participants who reported a history of pancreatitis, or participants whose data were based upon proxy responses. Further, no notable differences in pooled risk estimates emerged across strata of sex, age, race, study type, and study area.

CONCLUSION

This collaborative-pooled analysis provides additional evidence for a positive association between heavy alcohol consumption and the risk of pancreatic cancer.

Plasma cotinine levels and pancreatic cancer in the EPIC cohort study

Smoking is an established risk factor for pancreatic cancer, previously investigated by the means of questionnaires. Using cotinine as a biomarker for tobacco exposure allows more accurate quantitative analyses to be performed. This study on pancreatic cancer, nested within the European Prospective Investigation into Cancer and Nutrition (EPIC cohort), included 146 cases and 146 matched controls. Using liquid chromatography-mass spectrometry, plasma cotinine levels were analyzed on average 8.0 years before cancer onset (5-95% range: 2.8-12.0 years). The relation between plasma cotinine levels and pancreatic cancer was analyzed with conditional logistic regression for different levels of cotinine in a population of never and current smokers. This was also done for the self-reported number of smoked cigarettes per day at baseline. Every increase of 350 nmol/L of plasma cotinine was found to significantly elevate risk of pancreatic cancer [odds ratio (OR): 1.33, 95% confidence interval (CI): 1.11-1.60]. People with a cotinine level over 1187.8 nmol/L, a level comparable to smoking 17 cigarettes per day, have an elevated risk of pancreatic cancer, compared to people with cotinine levels below 55 nmol/L (OR: 3.66, 95% CI: 1.44-9.26). The results for self-reported smoking at baseline also show an increased risk of pancreatic cancer from cigarette smoking based on questionnaire information. People who smoke more than 30 cigarettes per day showed the highest risk compared to never smokers (OR: 4.15, 95% CI: 1.02-16.42). This study is the first to show that plasma cotinine levels are strongly related to pancreatic cancer.

Cigar and pipe smoking, smokeless tobacco use and pancreatic cancer: an analysis from the International Pancreatic Cancer Case-Control Consortium (PanC4)

BACKGROUND

Cigarette smoking is the best-characterized risk factor for pancreatic cancer. However, data are limited for other tobacco smoking products and smokeless tobacco.

MATERIALS AND METHODS

We conducted a pooled analysis of cigar and pipe smoking and smokeless tobacco use and risk of pancreatic cancer using data from 11 case-control studies (6056 cases and 11,338 controls) within the International Pancreatic Cancer Case-Control Consortium (PanC4). Pooled odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated by unconditional multiple logistic regression models adjusted for study center and selected covariates.

RESULTS

Compared with never tobacco users, the OR for cigar-only smokers was 1.6 (95% CI: 1.2-2.3), i.e. comparable to that of cigarette-only smokers (OR 1.5; 95% CI 1.4-1.6). The OR was 1.1 (95% CI 0.69-1.6) for pipe-only smokers. There was some evidence of increasing risk with increasing amount of cigar smoked per day (OR 1.82 for ≥ 10 grams of tobacco), although not with duration. The OR for ever smokeless tobacco users as compared with never tobacco users was 0.98 (95% CI 0.75-1.3).

CONCLUSION

This collaborative analysis provides evidence that cigar smoking is associated with an excess risk of pancreatic cancer, while no significant association emerged for pipe smoking and smokeless tobacco use.

Smoking is related to pancreatic fibrosis in humans

OBJECTIVES

Smokers are at risk for pancreatic cancer (PC) and other pancreatic diseases. Cigarette smoking also aggravates the risk of PC in patients with hereditary and chronic pancreatitis (CP) and results in a higher incidence of acute pancreatitis and relapses in CP. Both PC and CP are characterized by a progressive fibrosis. Recently, two studies on rats reported that tobacco smoking is associated with chronic pancreatic inflammation with fibrosis and scarring of pancreatic acinar structures. In this study, we aimed to confirm a relationship between cigarette smoking and pancreatic fibrosis (PF) in humans.

METHODS

In this retrospective study, pancreatic and liver tissue acquired during autopsy was collected and analyzed. PF was scored by assessing severity of intralobular, extralobular, and total PF: grade 0 (normal or mild; 0-25% PF), grade 1 (moderate; 25-50% PF), and grade 2 (severe; >50%). Information on smoking habits was extracted from (electronic) medical records.

RESULTS

Of 900 autopsies performed from January 2005 to December 2007, a minority of patients (n=111) met all inclusion criteria for analysis. Grade 2-3 total PF and intralobular PF was significantly more present in smokers vs. "never-smokers" (total: 42.9 vs. 26.5%, P=0.027 and intralobular: 39.3 vs. 15.6%, P=0.013), whereas no differences could be found between never-smokers and ex-smokers and between ex-smokers and smokers. When we took into account interlobular PF, no differences between all groups were observed. No relationship between PF and age (P=0.893), body mass index (P=0.707), and pancreatic lipomatosis (P=0.916) was observed.

CONCLUSIONS

To our knowledge, no study in humans had studied the effect of tobacco smoking on pancreatic tissue. We have demonstrated for the first time that current cigarette smoking is associated with total PF-specifically, intralobular PF-as compared with nonsmokers.

Nutrition treatment of deficiency and malnutrition in chronic pancreatitis: a review

Chronic pancreatitis results in exocrine and endocrine dysfunction, affecting normal digestion and absorption of nutrients. In individuals with chronic pancreatitis, nutrition status may be further affected by poor dietary intake, often related to alcoholism. However, some deficiencies may be overlooked, potentially leading to nutrition-related problems with bone health and fatigue. The aim of this article is to describe the deficiencies that occur and to propose an evidence-based algorithm for the nutrition assessment and treatment of patients with chronic pancreatitis.

Recombinant human bone morphogenetic protein-2 and pancreatic cancer: a retrospective cohort study

PURPOSE

To assess whether use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during lumbar spinal fusion surgery affects subsequent risk of pancreatic cancer.

METHODS

Using US Medicare claims data, we performed a retrospective cohort study of patients who underwent lumbar spinal fusion surgery between October 2003 and December 2005. The study population, all >66 years, was identified from procedure codes for lumbar fusion. Claims for a bone morphogenetic protein (BMP) served as a proxy for rhBMP-2 exposure (another BMP product shared the same code). Pancreatic cancer was identified from claims indicating this diagnosis and cancer-specific therapy. We used Cox proportional hazard regression to estimate hazard ratios (HRs) and 95%CIs.

RESULTS

Of the 93,654 patients in the study, the mean age was 75 years, and 16.5% had claims for BMP. During a mean 1.4 years of follow-up, 91 patients were diagnosed with pancreatic cancer (eight in the BMP- and 83 in the non-BMP cohort). Consistent with previous research, pancreatic cancer was associated with older age, male gender, black race, and diabetes mellitus. Compared to those who did not receive BMP, patients exposed to BMP were not at increased risk of pancreatic cancer (adjusted HR=0.70, 95%CI: 0.34-1.45). A chart review substudy validated the exposure measure; 52/55 patients with claims for BMP received rhBMP-2.

CONCLUSIONS

In this large study of elderly patients who underwent lumbar fusion surgery, exposure to BMP was not associated with an increased risk of pancreatic cancer.

Past medical history and pancreatic cancer risk: Results from a multicenter case-control study

PURPOSE

To investigate risk factors that may be linked to pancreatic cancer.

METHODS

We designed a multicenter population-based case-control (823 cases, 1679 control patients) study with data collection by using a common protocol and questionnaire. Participating centers were located in Australia, Canada, the Netherlands, and Poland.

RESULTS

After adjustment for confounding factors, a positive history of pancreatitis was associated with pancreatic cancer (odds ratio [OR], 4.68; 95% confidence interval [95% CI], 2.23-9.84). The risk was especially high in heavy smokers (OR, 15.4; 95% CI, 3.18-74.9). Patients with diabetes had an increased risk of developing pancreatic cancer (OR, 2.16; 95% CI, 1.60-2.91). The risk was highest in the first year after the development of diabetes (OR, 6.68; 95% CI, 3.56-12.6) and decreased over time. A history of allergy was associated with a reduced risk of pancreas cancer (OR, 0.64; 95% CI, 0.50-0.82).

CONCLUSIONS

Patients with newly diagnosed diabetes and patients with pancreatitis, particularly in heavy smokers, have an increased risk for developing pancreatic cancer. In addition to being risk factors, these conditions could be early manifestations of underlying pancreatic cancer. A history of allergy decreases the risk of pancreatic cancer.

Nuclear factor kappaB-activated monocytes contribute to pancreatic cancer progression through the production of Shh

Recently, it was reported that Hh signaling is activated in tumor stromal cells but not in tumor cells themselves and that stromal cells may play a role in the proliferation of cancer cells. This suggests the possibility that stromal cells have an important role in the proliferation of tumor cells that may be mediated through Hh signaling. In this report, we present for the first time that inflammation-stimulated monocytes produce Shh through activation of the NF-kappaB signaling pathway, and that the Shh produced promotes the proliferation of pancreatic cancer cells in a paracrine manner through Hh signaling.

Cigarette smoking, environmental tobacco smoke exposure and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition

Cigarette smoking is an established risk factor for pancreatic cancer. However, prospective data for most European countries are lacking, and epidemiologic studies on exposure to environmental tobacco smoke (ETS) in relation to pancreatic cancer risk are scarce. We examined the association of cigarette smoking and exposure to ETS with pancreatic cancer risk within the European Prospective Investigation into Cancer and Nutrition (EPIC). This analysis was based on 465,910 participants, including 524 first incident pancreatic cancer cases diagnosed after a median follow-up of 8.9 years. Estimates of risk were obtained by Cox proportional hazard models and adjusted for weight, height, and history of diabetes mellitus. An increased risk of pancreatic cancer was found for current cigarette smokers compared with never smokers (HR = 1.71, 95% CI = 1.36-2.15), and risk increased with greater intensity and pack-years. Former cigarette smokers who quit for less than 5 years were at increased risk of pancreatic cancer (HR = 1.78, 95% CI = 1.23-2.56), but risk was comparable to never smokers after quitting for 5 years or more. Pancreatic cancer risk was increased among never smokers daily exposed to ETS (for many hours) during childhood (HR = 2.61, 95% CI = 0.96-7.10) and exposed to ETS at home and/or work (HR = 1.54, 95% CI = 1.00-2.39). These results suggest that both active cigarette smoking, as well as exposure to ETS, is associated with increased risk of pancreatic cancer and that risk is reduced to levels of never smokers within 5 years of quitting.

Potential carcinogenic effects of cigarette smoke and Swedish moist snuff on pancreas: a study using a transgenic mouse model of chronic pancreatitis

The risk of pancreatic cancer is increased in both Snus (the Swedish variant of oral smokeless tobacco) users and, to a greater extent, in cigarette smokers. Concurrent chronic pancreatitis further increases the risk in cigarette smokers. Little is known about the mechanism by which cigarette smoke or Snus increase the risk of pancreatic cancer in individuals with chronic pancreatitis. This study examined the carcinogenic effects of an aqueous extract of cigarette smoke (tobacco smoke, TS) or Snus in an Elastase-IL-1beta transgenic mouse model of chronic pancreatitis. Both transgenic and wild-type (WT) mice were fed diluted TS water or Snus-containing diet for up to 15 months, and monitored for phenotypic and molecular changes in the pancreas. Both TS- and Snus-treated Elastase-IL-1beta mice, but not WT mice, developed significant pancreatic ductal epithelial flattening and severe glandular atrophy compared with untreated transgenic mice. Ductal epithelial cells displayed a high proliferative index, minimal apoptosis, and induction of COX-2 in the setting of chronic inflammation. Up-regulation of TNF-alpha correlated with the onset of severe glandular atrophy. In comparison with Snus-treated mice, TS-Elastase-IL-1beta mice had an earlier onset and a greater extent of phenotypic changes, which were associated with up-regulation of TNF-alpha and increased expression of IL-6, TGF-beta, and SDF-1. Collectively, these findings provide new insights into the mechanism by which tobacco products are likely to promote carcinogenesis in the setting of chronic pancreatitis.

Incidence rates of exocrine and endocrine pancreatic cancers in the United States

Descriptive studies of pancreatic cancer incidence have been sparse particularly in terms of tumor histology and stage. The purpose of this study was to examine the incidence rate trends of exocrine and endocrine pancreatic cancers by demographic and tumor characteristics using data from the Surveillance, Epidemiology, and End Results (SEER) program from 1977 to 2005. During this period, the incidence of exocrine pancreatic cancer generally decreased whereas the incidence of endocrine pancreatic cancer increased. This difference in trends by histology was evident across age, gender, and racial groups. It was also evident among different racial/ethnic groups using data from 1992 to 2005. Variation in trends was observed by stage. The incidence of exocrine cancers declined for all stages except regional. Endocrine cancer incidence increased for all tumor stages, and the increase was most prominent for localized tumors. When exocrine tumors were stratified by tumor subsite, the incidence of cancers in the tail and body regions increased while the incidence in other regions decreased. While better detection and classification of tumors through improved diagnostic procedures may be related to these changing trends, etiologic factors warrant study.

Menstrual and reproductive factors and pancreatic cancer in the SEARCH program of the IARC

We conducted a population-based case-control study on the relation of menstrual and reproductive factors and hormone use with pancreatic cancer risk among female participants of the SEARCH program study. We evaluated 367 cases of ductal adenocarcinoma and 821 controls for associations between pancreatic cancer and age at menarche, age at menopause, number of pregnancies, exogenous hormone use, and history of gynaecologic surgery. Among directly interviewed and proxy participants, we found a statistically significant association for having age of menarche at 11 years or younger compared with menarche at ages 12-13 years (OR = 1.8, 95% CI = 1.1-3.1). This result was consistent, but not statistically significant, among three of the four studies analyzed, and when the data were analyzed separately by response status (direct vs. proxy interviews). No other menstrual or reproductive factors were associated with pancreatic cancer risk in this study. In conclusion, earlier age at menarche may be weakly associated with pancreatic cancer, but it seems unlikely that menstrual and reproductive factors play more than only a minor role in pancreatic cancer. Additional analyses in large prospective study populations and in pooled studies may help to clarify remaining inconsistencies.

Alcohol use and risk of pancreatic cancer: the NIH-AARP Diet and Health Study

The epidemiologic evidence for the role of alcohol use in pancreatic cancer development is equivocal. The authors prospectively examined the relation between alcohol use and risk of pancreatic cancer among 470,681 participants who were aged 50-71 years in 1995-1996 in the US National Institutes of Health-AARP Diet and Health Study. The authors identified 1,149 eligible exocrine pancreatic cancer cases through December 2003. Multivariate Cox proportional hazards regression models were used to calculate relative risks and 95% confidence intervals with the referent group being light drinkers (<1 drink/day). The relative risks of developing pancreatic cancer were 1.45 (95% confidence interval (CI): 1.17, 1.80; P(trend) = 0.002) for heavy total alcohol use (>or=3 drinks/day, approximately 40 g of alcohol/day) and 1.62 (95% CI: 1.24, 2.10; P(trend) = 0.001) for heavy liquor use, compared with the respective referent group. The increased risk with heavy total alcohol use was seen in never smokers (relative risk = 1.35, 95% CI: 0.79, 2.30) and participants who quit smoking 10 or more years ago before baseline (relative risk = 1.41, 95% CI: 1.01, 2.00). These findings suggest a moderately increased pancreatic cancer risk with heavy alcohol use, particularly liquor; however, residual confounding by cigarette smoking cannot be completely excluded.

Genetic mutations associated with cigarette smoking in pancreatic cancer

Cigarette smoking doubles the risk of pancreatic cancer, and smoking accounts for 20% to 25% of pancreatic cancers. The recent sequencing of the pancreatic cancer genome provides an unprecedented opportunity to identify mutational patterns associated with smoking. We previously sequenced >750 million bp DNA from 23,219 transcripts in 24 adenocarcinomas of the pancreas (discovery screen). In this previous study, the 39 genes that were mutated more than once in the discovery screen were sequenced in an additional 90 adenocarcinomas of the pancreas (validation screen). Here, we compared the somatic mutations in the cancers obtained from individuals who ever smoked cigarettes (n = 64) to the somatic mutations in the cancers obtained from individuals who never smoked cigarettes (n = 50). When adjusted for age and gender, analyses of the discovery screen revealed significantly more nonsynonymous mutations in the carcinomas obtained from ever smokers (mean, 53.1 mutations per tumor; SD, 27.9) than in the carcinomas obtained from never smokers (mean, 38.5; SD, 11.1; P = 0.04). The difference between smokers and nonsmokers was not driven by mutations in known driver genes in pancreatic cancer (KRAS, TP53, CDKN2A/p16, and SMAD4), but instead was predominantly observed in genes mutated at lower frequency. No differences were observed in mutations in carcinomas from the head versus tail of the gland. Pancreatic carcinomas from cigarette smokers harbor more mutations than do carcinomas from never smokers. The types and patterns of these mutations provide insight into the mechanisms by which cigarette smoking causes pancreatic cancer.

Does quality of observational studies affect the results of a meta-analysis?: the case of cigarette smoking and pancreatic cancer

OBJECTIVES

A meta-analysis of observational studies on association between cigarette smoking and pancreatic cancer was performed to focus, particularly, on the role of the studies' quality in affecting meta-analysis results.

METHODS

A bibliographic search was carried out on PubMed and EMBASE databases until February 15, 2008. Key words were "pancreatic neoplasms," "pancreatic cancer," "smoking," "smoke," "cigarette," "case-control studies," and "cohort studies." Studies about cigarette smoking and pancreatic cancer were selected and assessed on quality. STATA 9.0 was used.

RESULTS

Six cohort studies and 24 case-control studies were selected, with median quality scores of 8 (range, 3) and 10 (range, 8), respectively. Pooled case-control studies' odds ratio (OR) and cohort studies' risk ratio were, respectively, 1.45 (95% confidence interval [CI], 1.33-1.57) and 1.78 (95% CI, 1.64-1.92). After stratifying for quality scoring, high-quality-scored case-control studies yielded an OR of 1.38 (95% CI, 1.27-1.49), whereas the others gave an OR of 1.52 (95% CI, 1.34-1.73). The results of meta-analysis for cohort studies showed a risk ratio of 1.74 (95% CI, 1.61-1.90) and of 2.10 (95% CI, 1.64-2.67), respectively, for high- and low-quality score studies.

CONCLUSIONS

There is evidence that cigarette smoking is an important risk factor for pancreatic cancer, but the estimate of the association greatly relies on the studies' quality.

Inhibition of pancreatic cancer cell proliferation by propranolol occurs through apoptosis induction: the study of beta-adrenoceptor antagonist's anticancer effect in pancreatic cancer cell

OBJECTIVES

Propranolol inhibited pancreatic cancer cell proliferation by blocking signaling through the beta-adrenoceptor. We hypothesized that propranolol may suppress pancreatic cancer cell growth through induction of apoptosis.

METHODS

The beta-adrenoceptor antagonist propranolol, beta1-adrenoceptor antagonist metoprolol, and beta2-adrenoceptor antagonist butoxamine were used to induce apoptosis in PC-2 cells. The mRNA and protein expression of beta1- and beta2-adrenoceptors was analyzed using reverse transcriptase-polymerase chain reaction and Western blot. The apoptotic index was determined using Hoechst 33342 fluorescent staining, TUNEL, and annexin V and fluorescein isothiocyanate/propidium iodide flow cytometry assay. The expression of caspase 3, caspase 9, and caspase 8 was analyzed using Western blotting.

RESULTS

PC-2 cell line expressed mRNA and protein for both of beta1- and beta2-adrenoceptors. The Hoechst staining, TUNEL, and flow cytometry assay documented that the 3 drugs increased the number of apoptotic cells; the rate of apoptosis was the highest using butoxamine followed by propranolol, whereas the least was using metoprolol. beta-Adrenoceptor antagonists therapy affected caspase 3 and caspase 9 expression.

CONCLUSIONS

The rate of apoptosis in PC-2 cells was higher after treatment with butoxamine than propranolol, suggesting that propranolol induces apoptosis in PC-2 cells via the beta2-adrenoceptors principally. Our data could be useful for developing beta-adrenoceptor antagonists for inducing apoptosis in pancreatic cancer cells.

Effect of nicotine and cigarette smoke on an experimental model of intraepithelial lesions and pancreatic adenocarcinoma induced by 7,12-dimethylbenzanthracene in mice

OBJECTIVES

To evaluate the effects of nicotine and cigarette smoke exposure on mice submitted to 7,12-dimethylbenzanthracene (DMBA) model of pancreatic carcinogenesis.

METHODS

One hundred fourteen male mice were divided into the DMBA-n and DMBA-s groups: the DMBA-n group was given 2 mg/kg per dose of nicotine ([3-(1-methyl-2-pyrrolidinyl)pyridine]) subcutaneously for 45 days, and the DMBA-s group was exposed to 100 mg/m of cigarette smoke. At day 16, 1 mg of DMBA crystals was implanted in the pancreatic head of both groups. Euthanasia was performed in all mice 30 days after the surgery. The specimens were evaluated according to the following criteria: normal ducts, reactive hyperplasia, pancreatic intraepithelial neoplasm 3 (PanIN-3), and carcinoma. For statistical analysis, DMBA-exclusive ([DMBA-e] historical control group) was included.

RESULTS

The frequency of PanIN in the 3 groups was almost the same when considering the higher-grade lesions: DMBA-e (16 [66.7%]), DMBA-s (20 [66.7%]), and DMBA-n (12 [44.4%]). Pancreatic adenocarcinoma has a higher frequency in the DMBA-n group (14 [51.9%]) than in the DMBA-e (4 [16.7%]) and DMBA-s (4, 13.3%) groups. The DMBA-s group has the highest score of PanIN-3 (40%). The differences among the groups were statistically significant (P = 0.05, Fisher exact test).

CONCLUSIONS

Nicotine but not cigarette smoke promotes pancreatic DMBA carcinogenesis in mice. Pancreatic adenocarcinomas and PanINs have the same phenotypic appearance as those that occur in humans.

Family history is a significant risk factor for pancreatic cancer: results from a systematic review and meta-analysis

Epidemiologic evidence suggests a family history of pancreatic cancer (PC) is a risk factor for the disease, yet the magnitude of risk varies between studies. We performed a systematic review of studies that quantified familial risks of PC, and through a meta-analysis, obtained more precise estimates of familial risk. A MEDLINE search identified published studies that reported relative risks (RR) of PC associated with a family history of the disease. A random effects model was used to summarize study-specific RRs and 95% confidence intervals (CI). Sensitivity and sub-group analyzes were performed. Seven case-control and two cohort studies involving 6,568 PC cases were identified. There was no evidence of statistical heterogeneity between studies (I(2) = 0%; P = 0.483). Results from case-control (RR = 2.82; 95% CI: 1.99-3.66) and cohort (RR = 1.62; 95% CI: 1.28-1.97) studies showed a significant increase in PC risk associated with having an affected relative, with an overall summary RR = 1.80 (95% CI: 1.48-2.12). Similar RR were observed for early (RR = 2.69; 95% CI: 0.56-4.82) and later (RR = 3.41; 95% CI: 0.79-6.03) onset disease in the index case. Data was too sparse to generate an overall summary RR based on the number or type of affected relatives. Individuals with a family history of PC have nearly a two-fold increased risk for developing PC compared to those without such a history. Families with two or more PC cases may benefit from comprehensive risk assessment that involves collection of detailed family history information and data regarding various risk factors for PC, especially smoking history. Those at highest risk may be referred to screening programs and studies; these are important steps toward early detection and greater odds of surviving this disease.

Pancreatic intraepithelial neoplasia and ductal adenocarcinoma induced by DMBA in mice: effects of alcohol and caffeine

PURPOSE

To evaluate the effects of alcohol and caffeine in a pancreatic carcinogenesis mouse model induced by 7,12-dimethylbenzantracene (DMBA), according to the PanIN classification system.

METHODS

120 male, Mus musculus, CF-1 mice were divided into four groups. Animals received either water or caffeine or alcohol or alcohol + caffeine in their drinking water. In all animals, 1 mg of DMBA was implanted into the head of the pancreas. After 30 days, euthanasia was performed; excised pancreata were then fixed in formalin, stained with hematoxylin-eosin and categorized as follows: normal ducts, reactive hyperplasia, PanIN-1A, PanIN-1B, PanIN-2, PanIN-3 or adenocarcinoma.

RESULTS

PanIN lesions were verified in all groups. Adenocarcinoma was detected in 15% of animals in the caffeine group, 16.6% in the water group, 23.8% in the alcohol + caffeine group and 52.9% in the alcohol group (P<0.05).

CONCLUSIONS

The experimental pancreatic carcinogenesis mouse model using DMBA effectively induces PanIN lesions and pancreatic adenocarcinoma. This study verified the association between alcohol use and pancreatic adenocarcinoma; caffeine did not present the same effect.

Genetic susceptibility in pancreatic ductal adenocarcinoma

BACKGROUND

The strongest risk factors for pancreatic adenocarcinoma are tobacco smoking and increasing age. However, only a few smokers or elderly individuals develop the disease and genetic factors are also likely to be important.

METHODS

The literature on genetic factors modifying susceptibility to cancer was reviewed, with particular regard to the interindividual variation that exists in the development of pancreatic adenocarcinoma.

RESULTS

Tobacco-derived carcinogen-metabolizing enzyme gene variants have been the main area of study in stratifying the risk of sporadic pancreatic cancer. Inconsistent results have emerged from the few molecular epidemiological studies performed.

CONCLUSION

There is great scope for further investigation of critical pathways and unidentified genetic influences may be revealed. This may eventually allow the identification of individuals at high risk who might be targeted for screening.

Analysis of mortality rates for pancreatic cancer across the world

INTRODUCTION

Pancreas cancer is the fourth commonest cause of cancer-related mortality across the world, with incidence equalling mortality. A recent study has suggested that both the incidence and the mortality of pancreatic cancer are falling in the UK. We investigated whether this trend was being seen all over the world.

METHODS

Age-standardized mortality (world) rates [ASR(W)] for pancreatic cancer were extracted separately for males and females from a database maintained by the International Agency for Research on Cancer for 51 countries across the world (Europe, 33 countries; Americas, 8 countries; and Asia, 10 countries) for the period 1992-2002; log-linear regression analysis was performed to analyse trends in the past decade.

RESULTS

In the period 1992-2002, the ASR(W) remained static across most countries for both sexes. The highest mortality rates (for both sexes) were seen in Central Europe [range: men (8-12), women (4.5-7)] with trends towards increasing mortality in Romania (p<0.001), along with Albania, Spain and Croatia (p<0.01). Korea in the Far East, too, demonstrated increasing mortality trends for both sexes (men p<0.001, women p<0.01). Increasing mortality trends were also observed among women in France (p<0.001). In Canada, there was a decline in mortality [men (7.5-6.4), women (5.9-5); p<0.01], while for men there was a downward trend in Ireland, the UK, Switzerland, Austria, and Poland [p<0.05].

CONCLUSION

The changes perhaps reflect standardization and consolidation of diagnostic tests for pancreatic cancer in the Western world and further in-depth analysis would be required.

Allergies are associated with reduced pancreas cancer risk: A population-based case-control study in Ontario, Canada

Pancreatic adenocarcinoma is one of the deadliest cancers with mortality rates almost equaling incidence rates. Each year, approximately 3,500 Canadians are diagnosed with this disease. Although somewhat inconsistent, epidemiological studies have found that allergies are associated with a reduced pancreas cancer risk while there appears to be no association with asthma. These associations were evaluated in a population-based case-control study conducted in Ontario. Incident cases of pancreatic adenocarcinoma, identified through the Ontario Cancer Registry (OCR), and diagnosed April 1, 2003 to June 1, 2006, were recruited by the Ontario Pancreas Cancer Study (OPCS). Controls were recruited from the Ontario Familial Colorectal Cancer Registry (OFCCR). Data on 276 cases and 378 controls were available for the current study. Multivariable logistic regression analysis was used to obtain age-adjusted odds ratio (AOR) estimates. Ever having allergies or hayfever was associated with reduced pancreas cancer risk (OR = 0.43, 95% confidence interval (CI): 0.29-0.63). There was no association observed between a history of asthma and pancreas cancer risk. Findings are of great importance to understanding the biological mechanisms involved in pancreas cancer development.

Increased expression of matrix metalloproteinases-21 and -26 and TIMP-4 in pancreatic adenocarcinoma

Pancreatic adenocarcinoma is known for early aggressive local invasion, high metastatic potential, and a low 5-year survival rate. Matrix metalloproteinases (MMPs) play important roles in tumor growth and invasion. Earlier studies on pancreatic cancer have found increased expression of certain MMPs to correlate with poorer prognosis, short survival time or presence of metastases. We studied the expression of MMP-21, -26, and tissue inhibitor of matrix metalloproteinases (TIMP)-4 in 50 tissue samples, including 25 adenocarcinomas, seven other malignant pancreatic tumors, and 18 control samples of non-neoplastic pancreatic tissue with immunohistochemistry. The regulation of MMP-21, -26, and TIMP-4 mRNAs by cytokines was studied with RT-PCR in pancreatic cancer cell lines PANC-1, BxPC-3, and AsPC-1. MMP-21, -26, and TIMP-4 were detected in cancer cells in 64, 40, and 60% of tumors, respectively. MMP-21 expressed in well-differentiated cancer cells and occasional fibroblasts, like TIMP-4, tended to diminish in intensity from grade I to grade III tumors. Patients with metastatic lymph nodes had increased expression of MMP-26 in actual tumor samples. All cultured cancer cell lines expressed MMP-21 basally at low levels, and presence of the protein was confirmed immunohistochemically in cultured cells. MMP-21 expression was induced by epidermal growth factor (EGF) in PANC-1 cells. MMP-26 was neither expressed basally nor induced by tumor necrosis factor alpha, transforming growth factor beta-1 (TGFbeta1), EGF, or interferon gamma. Basal TIMP-4 expression was lowest in the poorly differentiated cancer cell line PANC-1 compared to better-differentiated BxPC-3 and AsPC-1 cells. TIMP-4 expression was induced by TGFbeta1 in PANC-1 cells and by EGF in BxPC-3 cells. Our findings suggest that MMP-21 is not a marker of invasiveness, but rather of differentiation, in pancreatic cancer and it may be upregulated by EGF. The putative role of MMP-26 as a marker of metastases warrants further studies. Unlike other TIMPs, TIMP-4 was not upregulated in relation to aggressiveness of pancreatic cancer.

Early prediction of severity in acute pancreatitis using infrared spectroscopy of serum

BACKGROUND

One of the main problems in the management of acute pancreatitis (AP) is the scarcity of accurate predictors of disease severity.

METHODS

In a prospective design, we compared APACHE II score, C-reactive protein (CRP) level, and infrared (IR) spectral absorption of serum (wavelength 940 nm) in 167 consecutive patients with AP, 34 with predicted severe and 133 with mild form.

RESULTS

The IR spectral absorption levels on admission and at 24 h after admission were significantly (p < 0.05) lower in patients with severe AP. On admission, the sensitivity was 74, 56, and 44%; the specificity was 82, 83, and 81%; the positive predictive value was 51, 45, and 37%, and the negative predictive value was 92, 88, and 85%, for IR spectroscopy, APACHE II, and CRP, respectively. At 24 h, the sensitivity, specificity, positive predictive value, and negative predictive value was 82, 74, 44, and 94%; 65, 72, 37, and 89%; 68, 73, 39, and 90%, for IR spectroscopy, CRP, and APACHE II, respectively.

CONCLUSIONS

IR spectroscopy seems to be useful for early detection of severe AP and, in turn, for identifying patients requiring treatment in the intensive care unit and who can benefit from novel therapies.

Lifetime history of tobacco consumption and K-ras mutations in exocrine pancreatic cancer

OBJECTIVES

We analyzed the relation between mutations in codon 12 of the K-ras oncogene and lifetime consumption of tobacco in patients with exocrine pancreatic cancer (EPC).

METHODS

Incident cases of EPC were prospectively identified and interviewed during hospital admission about smoking and other factors. Exact logistic regression was used to compare EPC cases (N = 107) with and without K-ras mutations (case-case study).

RESULTS

Mutated cases were nonsignificantly less likely to have been smokers than wild-type cases: the odds ratio adjusted by age and sex was 0.54 (95% confidence interval, 0.10-2.69; P = 0.613). With respect to never smokers, adjusted odds ratios for former and current smokers were 0.79 and 0.36, respectively (P = 0.193). Pack-years smoked, years of smoking, and cigarettes smoked per year also tended to be higher in nonmutated than in mutated cases. Neither age at onset of smoking nor the time between quitting and diagnosis were associated with K-ras.

CONCLUSIONS

Tobacco does not play a major part in the acquisition of K-ras mutations in the pancreatic epithelium. Although both smoking and K-ras mutations have important roles in the etiopathogenesis of EPC, the 2 processes may act independently.

Trends in stomach and pancreatic cancer incidence and mortality in England and Wales, 1951–2000

Background

The aim of this study was to describe period and cohort effects in incidence and mortality of stomach and pancreatic cancer in England and Wales.

Methods

National figures for mortality (1951–2000) and incidence (1971–2000) were analysed using log-linear Poisson regression models to obtain relative risks (RR) for period (year of incidence or death) and cohort (year of birth).

Results

Stomach cancer shows a pronounced cohort effect in mortality with a decline in RR in men from 2·20 (1876) to 0·47 (1946) and a reduction from 2·79 to 0·41 for women. Mortality to incidence ratios are now less than 0·70. Pancreatic cancer mortality (men) RR rose from 0·91 (1951–1955) to a peak 1·11 (1976–1980) and then declined to 0·90 (1996–2000). Women showed a similar pattern. Cohort RR (men) increased to a peak of 1·14 in 1916 and declined to 1·01 in 1946, and continued to fall; the peak occurred slightly later in women. Mortality to incidence ratios were near 1 in the first 20 years, declining to 0·95 in the last 10 years.

Conclusion

Stomach cancer incidence has fallen continuously from 19th century birth cohorts onwards. Incidence of pancreatic cancer has fallen in successive birth cohorts after 1920; peak period risk was 1976–1990. Age-standardized mortality and case mortality for pancreatic cancer are declining.

The effect of modifiable risk factors on pancreatic cancer mortality in populations of the Asia-Pacific region

BACKGROUND

Pancreatic cancer accounts for about 220,000 deaths each year. Known risk factors are smoking and type 2 diabetes. It remains to be seen whether these risk factors are equally important in Asia and whether other modifiable risk factors have important associations with pancreatic cancer.

METHODS

An individual participant data analysis of 30 cohort studies was carried out, involving 420,310 Asian participants (33% female) and 99,333 from Australia/New Zealand (45% female). Cox proportional hazard models, stratified by study and sex and adjusted for age, were used to quantify risk factors for death from pancreatic cancer.

RESULTS

During 3,558,733 person-years of follow-up, there were 324 deaths from pancreatic cancer (54% Asia and 33% female). Mortality rates (per 100,000 person-years) from pancreatic cancer were 10 for men and 8 for women. The following are age-adjusted hazard ratios (95% confidence interval) for death from pancreatic cancer: for current smoking, 1.61 (1.12-2.32); for diabetes, 1.76 (1.15-2.69); for a 2-cm increase in waist circumference, 1.08 (1.02-1.14). All three relationships remained significant (P < 0.05) after adjustment for other risk factors. There was no evidence of heterogeneity in the strength of these associations between either cohorts from Asia and Australia/New Zealand or between the sexes. In men, the combination of cigarette smoking and diabetes more than doubled the likelihood of pancreatic cancer (2.47; 95% confidence interval, 1.17-5.21) in both regions.

CONCLUSIONS

Smoking, obesity, and diabetes are important and are potentially modifiable risk factors for pancreatic cancer in populations of the Asia-Pacific region. Activities to prevent them can be expected to lead to a major reduction in the number of deaths from this cancer, particularly in Asia with its enormous population.

Pancreatic carcinoma incidence and survival in Sweden in 1980-2000: a population-based study of 16,758 hospitalized patients with special reference to different therapies

AIMS

The purpose of this study was to analyze the incidence and survival of pancreatic carcinoma in Sweden during 1980-2000.

METHODS

In this population-based study the patients were identified in the Swedish Hospital Discharge Register and Cancer Register. Data were matched with those in the Register of Causes of Death in Sweden, and 16,758 patients were identified.

RESULTS

During the studied period, 1819 patients underwent pancreatic resection, 7457 were treated with palliative procedures and, in 7482, no intervention was carried out. The incidence of pancreatic carcinoma in Sweden for men dropped from 16 per 100,000 at the beginning of the period to 8 per 100,000 in the year 2000. Corresponding figures for women were 12 and 7, respectively. Patients who underwent pancreatic resection had significantly longer survival compared to the palliative procedure or no-intervention groups (p<0.001). After 12 months 49.7% of the resected patients were alive while the corresponding survival in the palliative procedure and no-intervention groups were 13.6% and 11.9%, respectively. The five-year survival rate after resection was 10.8%. In the resection group survival improved over time (p<0.001) and women survived longer than men (p<0.01), which was not the case in the palliative procedure or no-intervention groups.

CONCLUSIONS

During the study period, the incidence of pancreatic carcinoma in Sweden decreased markedly. The resection rate increased and only in this group of patients an improved survival was noted over time. The survival was the same for patients who underwent palliative interventions as for those who only received supportive care.

Update on pancreatic cancer and alcohol-associated risk

Ductal adenocarcinoma of the pancreas is characterized by extremely aggressive behavior, with an overall 5-year survival of <4%. Because conventional and specifically tailored therapeutic regimens have little impact on patient survival, epidemiological and molecular research aims at identifying and reducing risk factors. Cigarette smoking, obesity, diabetes mellitus, and chronic pancreatitis are amenable to medical prevention or therapy. Heavy alcohol consumption is an inconsistent single risk factor for pancreatic cancer but may promote carcinogenesis by increasing the risk of diabetes mellitus or chronic pancreatitis. For various agents, the key carcinogenic effect is probably an inflammatory response in the pancreatic tissue. On the molecular level, mutations of oncogenes and tumor suppressor genes, as well as various epigenetic alterations, such as overexpression of growth factors and their receptors, are important in tumorigenesis. Complete and safe surgical resection, together with adjuvant therapy, offers prolonged survival, with 5-year survival rates of approximately 25%. However, for unresectable or disseminated disease, which constitutes the vast majority of cases, treatment is palliative. Despite increasing knowledge about the molecular pathology of pancreatic cancer and despite advances in treatment, the overall course of the disease is dismal, and reinforced efforts to reduce incidence and improve outcome are needed desperately.

Cigarette smoking, elevated fasting serum glucose, and risk of pancreatic cancer in Korean men

Pancreatic cancer is one of the most fatal human cancers and continues to be a major unsolved health problem. The goal of this study was to estimate the independent effects and interactions between cigarette smoking and diabetes on the risk of pancreatic cancer in Korean male population. Cigarette smoking and the risk of incidence and death from pancreatic cancer were examined in a 10-year prospective cohort study of 446,407 Korean men aged 40 to 65 years who received health insurance from the National Health Insurance Corporation and who had a medical evaluation in 1992. Relative risks (RR) and 95% confidence intervals (CI) were calculated using a Cox proportional hazards model after adjusting for age, body mass index, exercise and alcohol use. Current smoking was associated with an increased risk of incidence (RR = 1.7, 95% CI = 1.6-1.9) and mortality (RR = 1.6, 95% CI = 1.4-1.7) from pancreatic cancer. The RR for pancreatic cancer increased with both duration and amount of smoking. Diabetes was also associated with an increased risk of both incidence (RR = 1.8, 95% CI = 1.5-2.2) and mortality (RR = 1.7, 95% CI = 1.4-2.1) from pancreatic cancer. There was no interaction between smoking and fasting serum glucose in terms of pancreatic cancer risk. Thus, our prospective study has demonstrated that cigarette smoking and elevated fasting serum glucose are independently associated with an increased risk of pancreatic cancer in a large cohort of Korean males.

Smoking--a trigger for chronic inflammation and cancer development in the pancreas

Tobacco smoke, with its complexity of constituents, damages the pancreatic organ in multiple ways. Smoke not only affects pancreatic secretion patterns via its nicotine content but induces inflammatory reactions and exerts carcinogenic effects by several other constituents. Smoke enhances ethanol-induced pancreatic injury and accelerates the development and progression of chronic pancreatitis independent of etiology. Through the process of inflammation, smoking contributes to pancreatic carcinogenesis. The experiment of Wittel and colleagues published in this issue of the American Journal of Gastroenterology sheds further light on this topic by reporting in great detail two different kinds of pancreatic damage in rats exposed to high doses of smoke.

Risk factors for pancreatic cancer

In the United States, the cumulative mortality or lifetime risk of dying from pancreatic cancer is about 1-2%, but although this form of cancer is rare, nearly all patients die from the disease within one to two years. Because of its lethality, pancreatic cancer now ranks fourth as a cause of death from cancer. There are country-specific differences in rates, perhaps explained by differences in life-style factors or diet. African-Americans in the USA have rates that are about 50% higher than Caucasians. Smoking is the major known risk factor for this cancer, explaining 20-30% of all cases. Another 5-10% of causes are caused by germline mutations, with mutations in BRCA2 being the most frequent. Two background diseases increase the risk of pancreatic cancer-pancreatitis, and diabetes. Major challenges presented by this cancer are: 1) determination of the molecular pathways that make this cancer so aggressive; 2) development of new modalities, perhaps based on proteomics, to enhance early detection.

Role of inflammation in pancreatic carcinogenesis and the implications for future therapy

BACKGROUND

The link between inflammation and pancreatic cancer has been observed for a number of gastrointestinal neoplasms. This review examines the role of inflammation in pancreatic carcinogenesis and how it can be utilised to develop new therapies against pancreatic cancer.

METHODS

A literature review of Pubmed, Medline and Web of Science databases was undertaken using the key words, pancreatic cancer, inflammation, inducible nitric oxide, interleukins, pro-inflammatory cytokines, cyclooxygenase-2, NF-kappa B, reactive oxygen species, DNA adducts, lipoxygenases, chemoprevention.

RESULTS

Epidemiological evidence and molecular studies both in vitro and in vivo all support the hypothesis that inflammation plays an important in the initiation and progression of pancreatic tumours.

CONCLUSION

Sustained damage caused by chronic inflammation may precede the onset of frank malignancy by a significant interval. As such, suppression of inflammatory changes and oxidative damage, may help delay or even prevent the inception of pancreatic neoplasia.