Molecular epidemiology of pancreatic cancer

Developments in pancreatic cancer emerging therapies, diagnostic methods, and epidemiology

Pancreatic cancer is still one of the deadliest malignancies, characterised by late-stage diagnosis, aggressive biology, and considerable resistance to conventional treatments. Despite improvements in understanding the molecular mechanisms and innovations in treatment, the overall survival remains abysmal: fewer than 9 % of patients survive beyond 5 years. By 2030, PC is predicted to become the second leading cause of cancer-related deaths in the U.S. owing to chemoresistance, rapid metastatic spread, and limited effective immunotherapeutic choices. This review highlights current progress in this field, including epidemiology, risk factors, diagnostic tools, and emerging biomarkers. Recent progress in genetic and molecular profiling has provided important information about pancreatic cancer. It has identified key mutations in genes like KRAS, TP53, CDKN2A, and SMAD4 that play a major role in driving the disease. Such revelations have provided the impetus to explore novel targeted therapies against these mutations. Furthermore, the advances in liquid biopsies incorporating circulating tumour cells, circulating tumour DNA, and exosomes hold substantial promise for early diagnosis, treatment response monitoring, and detection of minimal residual disease-any of which could radically transform PC management. While very limited options for the treatment of advanced-stage PC remain, the only potential curative treatment is surgery, yet only 10-15 % of patients are diagnosed with potentially resectable disease. Researchers are looking into new methods to help more patients qualify for surgery. This involves using chemotherapy and radiotherapy to reduce the size of the tumor before the operation. New chemotherapy treatments like FOLFIRINOX (which includes 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) have improved results for some patients, but they can still cause significant side effects. Immunotherapy, though revolutionary in other cancers, has had limited success in PC due to the tumour's immunosuppressive microenvironment. Researchers are looking into using immune checkpoint inhibitors together with chemotherapy, radiation, and drugs that target the surrounding tissue to improve the body's immune response. There is also considerable excitement surrounding personalised approaches with adoptive cell therapies such as CAR-T cells and TILs, which are trialled with early evidence of potential efficacy. Attempts are also being made to address the dense desmoplastic stroma of the tumour that characterises PC. Drugs that can fight resistance or new medicines that might affect the tumor environment, stop changes in surrounding tissues, and improve how drugs are delivered have shown some potential in laboratory tests so far. Nanoparticle-based drug delivery systems are also being developed to improve the bioavailability and targeted delivery of chemotherapy.

A Systematic Review and Meta-Analysis: Volatile Organic Compound Analysis in the Detection of Hepatobiliary and Pancreatic Cancers

BACKGROUND

Hepatobiliary cancers are notoriously difficult to detect, frequently leading to diagnosis in later stages of disease when curative treatment is not an option. The currently used biomarkers such as AFP (alpha-fetoprotein) and CA19.9 lack sensitivity and specificity. Hence, there is an unmet need for an alternative biomarker.

AIM

To evaluate the diagnostic accuracy of volatile organic compounds (VOCs) for the detection of hepatobiliary and pancreatic cancers.

METHODS

A systematic review of VOCs' use in the detection of hepatobiliary and pancreatic cancers was performed. A meta-analysis was performed using the software R. Heterogeneity was explored through meta-regression analysis.

RESULTS

A total of 18 studies looking at 2296 patients were evaluated. Pooled sensitivity and specificity of VOCs for the detection of hepatobiliary and pancreatic cancer were 0.79 (95% CI, 0.72-0.85) and 0.81 (97.5% CI, 0.76-0.85), respectively. The area under the curve was 0.86. Meta-regression analysis showed that the sample media used contributed to heterogeneity. Bile-based VOCs showed the highest precision values, although urine and breath are preferred for their feasibility.

CONCLUSIONS

Volatile organic compounds have the potential to be used as an adjunct tool to aid in the early diagnosis of hepatobiliary cancers.

Recent nanotechnology advancements to treat multidrug-resistance pancreatic cancer: Pre-clinical and clinical overview

Pancreatic cancer (PC) remains one of the most lethal and incurable forms of cancer and has a poor prognosis. One of the significant therapeutic challenges in PC is multidrug resistance (MDR), a phenomenon in which cancer cells develop resistance toward administered therapy. Development of novel therapeutic platforms that could overcome MDR in PC is crucial for improving therapeutic outcomes. Nanotechnology is emerging as a promising tool to enhance drug efficacy and minimize off-target responses via passive and/or active targeting mechanisms. Over the past decade, tremendous efforts have been made to utilize nanocarriers capable of targeting PC cells while minimizing off-target effects. In this review article, we first give an overview of PC and the major molecular mechanisms of MDR, and then we discuss recent advancements in the development of nanocarriers used to overcome PC drug resistance. In doing so, we explore the developmental stages of this research in both pre-clinical and clinical settings. Lastly, we discuss current challenges and gaps in the literature as well as potential future directions in the field.

Ethanol exposure of human pancreatic normal ductal epithelial cells induces EMT phenotype and enhances pancreatic cancer development in KC (Pdx1-Cre and LSL-KrasG12D ) mice

Alcohol is a risk factor for pancreatic cancer. However, the molecular mechanism by which chronic alcohol consumption influences pancreatic cancer development is not well understood. We have recently demonstrated that chronic ethanol exposure of pancreatic normal ductal epithelial cells (HPNE) induces cellular transformation by generating cancer stem cells (CSCs). Here, we examined whether chronic ethanol treatment induces epithelial–mesenchymal transition in HPNE cells and promotes pancreatic cancer development in KC (Pdx1‐Cre, and LSL‐Kras^G12D) mice. Our data demonstrate that chronic ethanol exposure of HPNE cells induces SATB2 gene and those cells became highly motile. Ethanol treatment of HPNE cells results in downregulation of E‐Cadherin and upregulation of N‐Cadherin, Snail, Slug, Zeb1, Nanog and BMI‐1. Suppression of SATB2 expression in ethanol‐transformed HPNE cells inhibits EMT phenotypes. KC mice fed with an ethanol‐containing diet show enhanced pancreatic cancer growth and development than those fed with a control diet. Pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of stem cell markers (CD133, CD44, CD24), pluripotency‐maintaining factors (cMyc, KLF4, SOX‐2, and Oct‐4), N‐Cadherin, EMT‐transcription factors (Snail, Slug, and Zeb1), and lower expression of E‐cadherin than those isolated from mice fed with a control diet. Furthermore, pancreas isolated from KC mice fed with an ethanol‐containing diet show higher expression of inflammatory cytokines (TNF‐α, IL‐6, and IL‐8) and PTGS‐2 (COX‐2) gene than those isolated from mice fed with a control diet. These data suggest that chronic alcohol consumption may contribute to pancreatic cancer development by generating inflammatory signals and CSCs.

Identification of potential diagnostic biomarkers in MMPs for pancreatic carcinoma

Pancreatic cancer (PC) is a malignant tumor which ranks fourth in cancer-related death. However, the specificity and sensitivity of traditional biomarkers such as carbohydrate antigen 19-9 no longer meet the clinical requirements.Tools as ONCOMINE and Gene Expression Profiling Interactive Analysis (GEPIA) were used to analyze the differential expression of matrix metalloproteinases (MMPs) in PC and adjacent tissues. For further analysis, we adopted database for annotation, visualization and integrated discovery (DAVID 6.8), transcriptional regulatory relationships unraveled by sentence-based text (TRRUST) and other tools. We also identified drugs targeted the selected MMPs.Eight MMPs (MMP1, MMP2, MMP7, MMP9, MMP11, MMP12, MMP14, and MMP28) were differentially expressed in PC and adjacent tissue. MMP1 (P = .0189), MMP7 (P = .000216), MMP11 (P = .0209), MMP14 (P = .00611) were correlated with the pathological stages of PC. Patients with higher expression of MMP1 (P = .0011), MMP2 (P = .011), MMP7 (P = .0081), MMP9 (P = .046), MMP11 (P = .0019), MMP12 (P = .0011), MMP14 (P = .0011), and MMP28 (P = 6.3e-06) showed poor prognosis. Ten transcription factors were associated with the up-regulation of selected MMPs. Marimastat (DB00786) was found to target selected MMPs.Our research revealed that selected MMPs played an important role in the early diagnosis and prognosis of PC.

AdipoRon: A Novel Insulin Sensitizer in Various Complications and the Underlying Mechanisms: A Review

BACKGROUND

AdipoRon is the first synthetic analog of endogenous adiponectin, an adipose tissue-derived hormone. AdipoRon possesses pharmacological properties similar to adiponectin and its ability to bind and activate the adipoR1 and adipoR2 receptors makes it a suitable candidate for the treatment of a multitude of disorders.

OBJECTIVE

In the present review, an attempt was made to compile and discuss the efficacy of adipoRon against various disorders.

RESULTS

AdipoRon is a drug that acts not only in metabolic diseases but in other conditions unrelated to energy metabolism. It is well- reported that adipoRon exhibits strong anti-obesity, anti-diabetic, anticancer, anti-depressant, anti-ischemic, anti-hypertrophic properties and also improves conditions like post-traumatic stress disorder, anxiety, and systemic sclerosis.

CONCLUSION

A lot is known about its effects in experimental systems, but the translation of this knowledge to the clinic requires studies which, for many of the potential target conditions, have yet to be carried out. The beneficial effects of AdipoRon in novel clinical conditions will suggest an underlying pathophysiological role of adiponectin and its receptors in previously unsuspected settings.

Smad4 deficiency substitutes Cdkn2b but not Cdkn2a downregulation in pancreatic cancer following induction of genetic events in adult mice

BACKGROUND

Minor progress in pancreatic cancer treatment and prognosis implies that more reliable animal models are urgently needed to decipher its molecular mechanisms and preclinical research. We recently reported a genetically engineered adult mouse model where Cdkn2b downregulation was required together with Cdkn2a downregulation to inactivate the Rb pathway. Besides, the role of Smad4, which is mutated more frequently than Cdkn2b in human pancreatic cancer, was determined critical on the development of the pancreas tumor by some reports. However, the impact of Smad4 deficiency in combination with PDAC-relevant mutations, such as Cdkn2a when induced in adult pancreas has not been completely elucidated in mice.

METHODS

Lentiviral delivered oncogene/tumor suppressors in adult pancreas. The development of pancreatic cancer was monitored. Hematoxylin and eosin staining and immunofluorescence were performed for pathological identification of the pancreatic cancer. Real-time polymerase chain reaction, immunofluorescence and western blot were used to test gene expression.

RESULTS

Loss of Smad4 could cooperate with alterations of KRAS, Trp53, and Cdkn2a to induce pancreatic cancer in adult mice. The role of Smad4 was mainly in downregulating the expression of Cdkn2b and further inducing phosphorylation of the Rb1 protein.

CONCLUSIONS

These findings show an essential role of Smad4 deficiency in pancreatic ductal adenocarcinoma (PDAC) formation. This model better recapitulates the adult onset, clonal origin, and genetic alterations in human PDAC and can be simply generated on a large-scale.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

Effect of High Fructose Corn Sirup on Pancreatic Ductal Adenocarcinoma Induced by Dimethyl Benzantracene (DMBA) in Rats

Increased risk of pancreatic cancer may be associated with consumption of sugar containing foods. The aim of this study was to evaluate the effect of peach nectar containing high fructose corn sirup (HFCS) consumption in a pancreatic carcinogenesis rat model induced by 7,12-Dimethyl benzanthracene (DMBA). Fifty-day-old male Sprague Dawley rats were fed with peach nectar containing HFCS + chow, peach nectar containing sucrose + chow and only chow. After 8 mo, feeding period, each group was divided into two subgroups, in which the rats were implanted with DMBA and no DMBA (sham). Histologic specimens were evaluated according to the routine tissue processing protocol. The animals with ad libitum access to pn-HFCS, pn-sucrose and chow (only) showed significant differences in chow consumption and glucose level. Necropsy and histopathologic findings showed tumor formation in the entire group treated with DMBA. Excluding one rat in chow group, which was classified as poorly differentiated type, the others were classified as moderately differentiated pancreatic ductal adenocarcinoma (PDAC). This study demonstrated that daily intake of HFCS did not increase body weight and there was no effect of peach nectar consumption on the development of PDAC induced by DMBA in rats.

Host-guest interaction studies of polycyclic aromatic hydrocarbons (PAHs) in alkoxy bridged binuclear rhenium (I) complexes

The interaction of two neutral alkoxy bridged binuclear rhenium(I) complexes, 1 and 2 [{Re(CO)₃(1,4-NVP)}₂(μ₂-OR)₂] (1, R = C₄H₉; 2, R = C₁₀H₂₁; 1,4-NVP = 4-(1-naphthylvinyl)pyridine] with polycyclic aromatic hydrocarbons (PAH) is investigated. UV-vis absorption, emission, ¹H NMR spectral titrations, TCSPC lifetime studies and DFT theoretical calculations were carried out to examine the binding responses of complexes 1 and 2 with various PAHs such as pyrene, naphthalene, anthracene and phenanthrene. The UV-Vis absorption spectra showed an increase in absorbance of the metal-to ligand charge-transfer (MLCT) and ligand centered (LC) bands upon addition of various PAH molecules to 1 and 2, whereas the emission behavior was found to show emission quenching, which might occur through energy transfer pathway. The binding constants (K) of complexes 1 and 2 for various PAHs are found to be in the order of 10⁴ M^-1 with a 1:1 binding mode, as determined from UV-vis absorption and emission spectral titration studies. ¹H NMR spectral studies show that the chemical shifts of pyrene guest and the 1,4-NVP moiety of 2 are shifted up-field, whilst the alkoxy protons do not show any appreciable change in their chemical shifts. It is believed that the open cavities present in the Re(I) complexes may lead to the recognition of PAHs via CH···π interaction.

Chronic ethanol exposure of human pancreatic normal ductal epithelial cells induces cancer stem cell phenotype through SATB2

The incidence of pancreatic cancer is on the rise. Risk factors for pancreatic cancer include alcohol toxicity and metabolic conditions such as obesity, hypertension, dyslipidaemia, insulin resistance and type 2 diabetes. However, the molecular mechanism by which chronic alcohol consumption contributes to pancreatic cancer is not well understood. The purpose of the study was to demonstrate the effects of long-term chronic ethanol exposure on the transformation of human pancreatic normal ductal epithelial (HPNE) cells. Our data showed that ethanol-transformed HPNE cells were more progressively transformed exhibiting spheroids and colonies, and anchorage-independent growth. These transformed cells contained high levels of reactive oxygen species and induced SATB2 expression. Furthermore, during ethanol-induced cellular transformation, cells gained the phenotypes of cancer stem cells (CSCs) by expressing pluripotency maintaining factors (Oct4, Sox2, cMyc and KLF4) and stem cell markers (CD24, CD44 and CD133). Ethanol-induced SATB2 can bind to the promoters of KLF4, Oct4, cMyc, Sox2, Bcl-2 and XIAP genes. Suppression of SATB2 expression in ethanol-transformed HPNE cells inhibited cell proliferation, colony formation and markers of CSCs and pluripotency. These data suggest that chronic alcohol consumption may contribute toward the development of pancreatic cancer by converting HPNE cells to cancer stem-like cells.

Pancreatic ductal adenocarcinoma can be detected by analysis of volatile organic compounds (VOCs) in alveolar air

Background

In the last decade many studies showed that the exhaled breath of subjects suffering from several pathological conditions has a peculiar volatile organic compound (VOC) profile. The objective of the present work was to analyse the VOCs in alveolar air to build a diagnostic tool able to identify the presence of pancreatic ductal adenocarcinoma in patients with histologically confirmed disease.

Methods

The concentration of 92 compounds was measured in the end-tidal breath of 65 cases and 102 controls. VOCs were measured with an ion-molecule reaction mass spectrometry. To distinguish between subjects with pancreatic adenocarcinomas and controls, an iterated Least Absolute Shrinkage and Selection Operator multivariate Logistic Regression model was elaborated.

Results

The final predictive model, based on 10 VOCs, significantly and independently associated with the outcome had a sensitivity and specificity of 100 and 84% respectively, and an area under the ROC curve of 0.99. For further validation, the model was run on 50 other subjects: 24 cases and 26 controls; 23 patients with histological diagnosis of pancreatic adenocarcinomas and 25 controls were correctly identified by the model.

Conclusions

Pancreatic cancer is able to alter the concentration of some molecules in the blood and hence of VOCs in the alveolar air in equilibrium. The detection and statistical rendering of alveolar VOC composition can be useful for the clinical diagnostic approach of pancreatic neoplasms with excellent sensitivity and specificity.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4452-0) contains supplementary material, which is available to authorized users.

Increased pancreas cancer in a bio-technological research laboratory

BACKGROUND

Pancreatic cancer is extremely rare among people under 55 years old. Its prognosis is poor, and the causal background remains almost unresolved. A previous study observed an increased occurrence of pancreatic cancer in workers in a French biochemical laboratory.

METHODS

CASE REPORT

During an approximate 10 year period in a Danish bio-chemical laboratory with about 50 stable employees, four cases of pancreatic cancer have been diagnosed at a mean age of 53 years. Approximately 0.02 cases should be expected if the laboratory employees had experienced the same rate of pancreatic cancer as that observed in the respective general Danish populations.

RESULT

All the four cases had a long-term occupational history of exposure to carcinogens during the early bio-technology period.

CONCLUSIONS

Causal conclusions cannot be made yet, but observation of former and present workers in biotechnological laboratories and their cancer occurrence is warranted.

Smoking prevalance and the degree of nicotine dependence among healthcare workers at the ataturk university medical facility

OBJECTIVE

In this study, we aimed to investigate smoking prevalence and the degree of nicotine dependence in our hospital healthcare workers.

MATERIALS AND METHODS

This study was conducted between January 2008 and June 2008 in our hospital (Medical Facility of Atatürk University). A total of 691 (370 females, 321 males) subjects were included in this study. A questionnaire, including demographic findings, tobacco consumption information and the Fagerström nicotine dependence test, was distributed to healthcare workers and collected.

RESULTS

The questionnaire was answered by 691 health workers, 46.5% of whom were male, and 53.5% of whom were female. Overall, the rate of smoking was 36.9%; 48% of males and 27.6% of females were current smokers. When classified according to clinic, the greatest rate of smoking was in the psychiatry clinic (60.0%), and the lowest rate of smoking was in the ear, nose and throat (ENT) Clinic (0.0%). Thirty-four percent of nurses, 18.7% of doctors, 45.5% of officers, and 50.4% of ancillary staff were smokers. According to education level, 50% of the cases (smokers) graduated from primary school, 45% of the cases graduated from high school and 26.9% of the cases graduated from university. The major reason for the initiation of smoking was attention-seeking behavior. The age at smoking initiation was 7 to 20 years in 83.9% of cases and 21 to 35 years in the remaining 16.1%. Thirty-five percent of smokers had very low levels of dependence, while 11.9% had very high levels dependence. Ninety-two percent of cases indicated they would prefer to work at a smoke-free hospital. Ninety-five percent of cases would support making this facility a smoke-free hospital.

CONCLUSION

The smoking rate was 36.9% amongst our hospital health workers. Smoking prevalence was higher in males (48%) than females (27.6%). The greatest smoking rate was amongst ancillary staff. Ninety-five percent of healthcare workers were supportive of a law requiring hospitals to be smoke-free.

Inhibition of NRF2 by PIK-75 augments sensitivity of pancreatic cancer cells to gemcitabine

We describe the potential benefit of PIK-75 in combination of gemcitabine to treat pancreatic cancer in a preclinical mouse model. The effect of PIK-75 on the level and activity of NRF2 was characterized using various assays including reporter gene, quantitative PCR, DNA-binding and western blot analyses. Additionally, the combinatorial effect of PIK-75 and gemcitabine was evaluated in human pancreatic cancer cell lines and a xenograft model. PIK-75 reduced NRF2 protein levels and activity to regulate its target gene expression through proteasome-mediated degradation of NRF2 in human pancreatic cancer cell lines. PIK-75 also reduced the gemcitabine-induced NRF2 levels and the expression of its downstream target MRP5. Co-treatment of PIK-75 augmented the antitumor effect of gemcitabine both in vitro and in vivo. Our present study provides a strong mechanistic rationale to evaluate NRF2 targeting agents in combination with gemcitabine to treat pancreatic cancers.

Clinico-pathological characteristics and clinical outcome of different histological types of pancreatic cancer in a large Middle European series

AIMS

Pancreatic cancer (PC) is a heterogeneous disease in terms of histological and molecular subtypes. The aim of this study was to evaluate the prognostic impact of different histological subtypes on cancer-specific survival (CSS) in a large single-centre Middle European cohort.

METHODS

We retrospectively studied the records of 400 consecutive PC patients who were treated from 2004 to 2010 at a single tertiary academic centre. The association of histological subtypes and parameters such as tumour stage, tumour grade, levels of tumour markers carcinoembryonic antigen and CA19-9 at diagnosis, was studied. CSS was calculated using the Kaplan-Meier method, and the influence of each parameter on CSS was assessed with univariate and multivariable Cox proportional models.

RESULTS

The survival time was significantly shorter in the ductal adenocarcinoma and acinar histological subtypes compared to neuroendocrine differentiation (p<0.001). No survival difference was observed between ductal adenocarcinomas and patients with a histological variant of ductal adenocarcinoma, namely, mucinous non-cystic adenocarcinoma (p=0.7). In multivariable analysis, ductal adenocarcinoma (HR=3.1, CI 1.6 to 6.1, p=0.001) and acinar carcinoma (HR=3.2, CI 1.3 to 8.5, p=0.016) were identified as independent predictors for CSS.

CONCLUSIONS

Our findings suggest that the main histological subtype is an independent predictor of CSS in patients with PC. Thus, our data underline the importance of routine assessment of histological type in PC for individual risk assessment. However, no clinical rationale for the subdivision of ductal adenocarcinoma and mucinous non-cystic adenocarcinoma can be supported by our study.

Coffee, tea, and sugar-sweetened carbonated soft drink intake and pancreatic cancer risk: a pooled analysis of 14 cohort studies

BACKGROUND

Coffee has been hypothesized to have pro- and anticarcinogenic properties, whereas tea may contain anticarcinogenic compounds. Studies assessing coffee intake and pancreatic cancer risk have yielded mixed results, whereas findings for tea intake have mostly been null. Sugar-sweetened carbonated soft drink (SSB) intake has been associated with higher circulating levels of insulin, which may promote carcinogenesis. Few prospective studies have examined SSB intake and pancreatic cancer risk; results have been heterogeneous.

METHODS

In this pooled analysis from 14 prospective cohort studies, 2,185 incident pancreatic cancer cases were identified among 853,894 individuals during follow-up. Multivariate (MV) study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and then pooled using a random-effects model.

RESULTS

No statistically significant associations were observed between pancreatic cancer risk and intake of coffee (MVRR = 1.10; 95% CI, 0.81-1.48 comparing ≥900 to <0 g/d; 237g ≈ 8oz), tea (MVRR = 0.96; 95% CI, 0.78-1.16 comparing ≥400 to 0 g/d; 237g ≈ 8oz), or SSB (MVRR = 1.19; 95% CI, 0.98-1.46 comparing ≥250 to 0 g/d; 355g ≈ 12oz; P value, test for between-studies heterogeneity > 0.05). These associations were consistent across levels of sex, smoking status, and body mass index. When modeled as a continuous variable, a positive association was evident for SSB (MVRR = 1.06; 95% CI, 1.02-1.12).

CONCLUSION AND IMPACT

Overall, no associations were observed for intakes of coffee or tea during adulthood and pancreatic cancer risk. Although we were only able to examine modest intake of SSB, there was a suggestive, modest positive association for risk of pancreatic cancer for intakes of SSB.

Evidence that serum levels of the soluble receptor for advanced glycation end products are inversely associated with pancreatic cancer risk: a prospective study

Cigarette smoking, obesity, type 2 diabetes, and, to a lesser extent, meat cooked at high temperatures are associated with pancreatic cancer. Cigarette smoke and foods cooked at higher temperatures are major environmental sources of advanced glycation end products (AGE). AGEs accumulate during hyperglycemia and elicit oxidative stress and inflammation through interaction with the receptor for AGEs (RAGE). Soluble RAGE (sRAGE) acts as an anti-inflammatory factor to neutralize AGEs and block the effects mediated by RAGE. In this study, we investigated the associations of prediagnostic measures of N(ε)-(carboxymethyl)-lysine (CML)-AGE and sRAGE with pancreatic cancer in a case-cohort study within a cohort of 29,133 Finnish male smokers. Serum samples and exposure information were collected at baseline (1985-1988). We measured CML-AGE, sRAGE, glucose, and insulin concentrations in fasting serum from 255 incident pancreatic cancer cases that arose through April 2005 and from 485 randomly sampled subcohort participants. Weighted Cox proportional hazard regression models were used to calculate relative risks (RR) and 95% CI, adjusted for age, years of smoking, and body mass index. CML-AGE and sRAGE were mutually adjusted. CML-AGE levels were not associated with pancreatic cancer [fifth compared with first quintile, RR (95% CI): 0.68 (0.38-1.22), P(trend) = 0.27]. In contrast, sRAGE levels were inversely associated with pancreatic cancer [fifth compared with first quintile, RR (95% CI): 0.46 (0.23-0.73), P(trend) = 0.002]. Further adjustment for glucose or insulin levels did not change the observed associations. Our findings suggest that sRAGE is inversely associated with pancreatic cancer risk among Finnish male smokers.

Cutaneous pancreatic metastasis: a case report and review of literature

Pancreatic cancer is one of the most dangerous human cancers and will continue to be a major unsolved health problem as we enter the 21^st century. This is the case despite advances in imaging technology and surgical management. Indeed, 80% to 90% of pancreatic cancers are diagnosed either at the locally advanced or metastatic stage. Cutaneous metastases originating from pancreatic cancer are relatively rare. The most common site of cutaneous metastasis is the umbilicus, and this is known as the Sister Joseph's nodule. Very few patients have been reported with cutaneous lesions disclosing a pancreatic carcinoma at sites other than the umbilical area. To the best of our knowledge, there have been no previous reports on cutaneous pancreatic metastasis in Egypt. This is a report on a patient with cutaneous pancreatic metastases at the neck and review of reported non-umbilical cutaneous metastases from pancreatic carcinoma in the literatures.

Trace detection of triphenylene by surface enhanced Raman spectroscopy using functionalized silver nanoparticles with bis-acridinium lucigenine

Surface enhanced raman scattering (SERS) of triphenylene (TP) has been recorded on Ag nanoparticles functionalized with the molecular assembler bis-acridinium lucigenine dication (LG) which approaches the adsorbate to the metal surface allowing for its detection. Structural information on the host and the analyte can be extracted from the SERS spectra of LG and LG/TP complex. The acridinium planes in LG are staggered, so cavities into which hydrophobic TP can be allocated are created. Moreover, the orientation of LG with respect to the metal surface changes from tilted to perpendicular when concentration of TP increases. However, perpendicular orientation of TP with respect to the metal surface is preferred according to the in-plane enhanced bands recorded in the SERS spectrum. The dependence of the Raman signal of TP on LG concentration has been checked, and trace concentrations of TP have been detected by this technique which therefore can be used as a chemical sensor of organic pollutants.

The role of one-electron reduction of lipid hydroperoxides in causing DNA damage

The in vivo metabolism of plasma lipids generates lipid hydroperoxides that, upon one-electron reduction, give rise to a wide spectrum of genotoxic unsaturated aldehydes and epoxides. These metabolites react with cellular DNA to form a variety of pre-mutagenic DNA lesions. The mechanisms of action of the radical precursors of these genotoxic electrophiles are poorly understood. In this work we investigated the nature of DNA products formed by a one-electron reduction of (13S)-hydroperoxy-(9Z,11E)-octadecadienoic acid (13S-HPODE), a typical lipid molecule, and the reactions of the free radicals thus generated with neutral guanine radicals, G(-H)(*). A novel approach was devised to generate these intermediates in solution. The two-photon-induced ionization of 2-aminopurine (2AP) within the 2'-deoxyoligonucleotide 5'-d(CC[2AP]TCGCTACC) by intense nanosecond 308 nm excimer laser pulses was employed to simultaneously generate hydrated electrons and radical cations 2AP(*+). The latter radicals either in cationic or neutral forms, rapidly oxidize the nearby G base to form G(-H)(*). In deoxygenated buffer solutions (pH 7.5), the hydrated electrons rapidly reduce 13S-HPODE and the highly unstable alkoxyl radicals formed undergo a prompt beta-scission to pentyl radicals that readily combine with G(-H)(*). Two novel guanine products in these oligonucleotides, 8-pentyl- and N(2)-pentylguanine, were identified. It is shown that the DNA secondary structure significantly affects the ratio of 8-pentyl- and N(2)-pentylguanine lesions that changes from 0.9:1 in single-stranded, to 1:0.2 in double-stranded oligonucleotides. The alkylation of guanine by alkyl radicals derived from lipid hydroperoxides might contribute to the genotoxic modification of cellular DNA under hypoxic conditions. Thus, further research is warranted on the detection of pentylguanine lesions and other alkylguanines in vivo.

Alcohol intake and pancreatic cancer risk: a pooled analysis of fourteen cohort studies

BACKGROUND

Few risk factors have been implicated in pancreatic cancer etiology. Alcohol has been theorized to promote carcinogenesis. However, epidemiologic studies have reported inconsistent results relating alcohol intake to pancreatic cancer risk.

METHODS

We conducted a pooled analysis of the primary data from 14 prospective cohort studies. The study sample consisted of 862,664 individuals among whom 2,187 incident pancreatic cancer cases were identified. Study-specific relative risks and 95% confidence intervals were calculated using Cox proportional hazards models and then pooled using a random effects model.

RESULTS

A slight positive association with pancreatic cancer risk was observed for alcohol intake (pooled multivariate relative risk, 1.22; 95% confidence interval, 1.03-1.45 comparing >or=30 to 0 grams/day of alcohol; P value, test for between-studies heterogeneity=0.80). For this comparison, the positive association was only statistically significant among women although the difference in the results by gender was not statistically significant (P value, test for interaction=0.19). Slightly stronger results for alcohol intake were observed when we limited the analysis to cases with adenocarcinomas of the pancreas. No statistically significant associations were observed for alcohol from wine, beer, and spirits comparing intakes of >or=5 to 0 grams/day. A stronger positive association between alcohol consumption and pancreatic cancer risk was observed among normal weight individuals compared with overweight and obese individuals (P value, test for interaction=0.01).

DISCUSSION

Our findings are consistent with a modest increase in risk of pancreatic cancer with consumption of 30 or more grams of alcohol per day.

Contribution of alcohol and tobacco use in gastrointestinal cancer development

Tobacco smoke and alcohol are major risk factors for a variety of cancer sites, including those of the gastrointestinal tract. Tobacco smoke contains a great number of mutagenic and carcinogenic compounds, including polycyclic carbohydrates, nitrosamines, and nicotine, while ethanol per se has only weak carcinogenic potential, but its first metabolite, acetaldehyde, is a mutagen and carcinogen, since it forms stable adducts with DNA. The possibility of proto-oncogene mutation in gastrointestinal mucosa cells may be associated with tobacco smoking-induced cancers through the formation of unfavorable DNA adducts. Individuals with defective DNA repair mechanisms and unfavorable genetic make-up for carcinogen metabolism may be at increased risk for gastrointestinal cancers. Individuals with a high production rate of acetaldehyde from ethanol also have an increased cancer risk when they drink chronically. These include individuals with a genetically determined increased acetaldehyde production due to alcohol dehydrogenase polymorphism and those with a decreased detoxification of acetaldehyde due to acetaldehyde dehydrogenase mutation. In addition, oral bacterial overgrowth due to poor oral hygiene also increases salivary acetaldehyde. Dietary deficiencies such as a lack of folate, riboflavine, and zinc may also contribute to the increase cancer risk in the alcoholic patient. It is of considerable importance that smoking and drinking act synergistically. Smoking increases the acetaldehyde burden following alcohol consumption and drinking enhances the activation of various procarcinogens present in tobacco smoke due to increased metabolic activation by an induced cytochrome P450-2E1-dependent microsomal biotransformation system in the mucosa of the upper digestive tract and the liver.

Novel Ras pathway inhibitor induces apoptosis and growth inhibition of K-ras-mutated cancer cells in vitro and in vivo

MT477 is a novel quinoline with potential activity in Ras-mutated cancers. In this study, MT477 preferentially inhibited the proliferation of K-ras-mutated human pulmonary (A549) and pancreatic (MiaPaCa-2) adenocarcinoma cell lines, compared with a non-Ras-mutated human lung squamous carcinoma cell line (H226) and normal human lung fibroblasts. MT477 treatment induced apoptosis in A549 cells and was associated with caspase-3 activation. MT477 also induced sub-G1 cell-cycle arrest in A549 cells. Although we found that MT477 partially inhibited protein kinase C (PKC), it inhibited Ras directly followed in time by inhibition of 2 Ras downstream molecules, Erk1/2 and Ral. MT477 also caused a reorganization of the actin cytoskeleton and formation of filopodias in A549 cells; this event may lead to decreased migration and invasion of tumor cells. In a xenograft mouse model, A549 tumor growth was inhibited significantly by MT477 at a dose of 1 mg/kg (P < 0.05 vs vehicle control). Taken together, these results support the conclusion that MT477 acts as a direct Ras inhibitor. This quinoline, therefore, could potentially be active in Ras-mutated cancers and could be developed extensively as an anticancer molecule with this in mind.

The association between selected risk factors for pancreatic cancer and the expression of p53 and K-ras codon 12 mutations

BACKGROUND

Pancreatic cancer is a major contributor to cancer mortality. Studies suggest that a few risk factors, including cigarette smoking, body mass index, having a relative with pancreatic cancer, and diabetes may be related to pancreatic cancer risk.

AIM OF THE STUDY

We conducted a case-control study in southeastern Michigan to examine the relation between the above mentioned risk factors and mutations of the K-ras oncogene and p53 tumor suppressor gene.

METHODS

Two hundred forty-five patients with newly diagnosed pancreatic cancer and 420 general population controls were enrolled in the study. For this analysis, all case subjects were restricted to the pancreatic cancer patients that had tissue blocks available for study (n = 51). In-person interviews were conducted to ascertain information on demographic and lifestyle factors. Adjusted logistic regression analyses were conducted to compare various subject characteristics of pancreatic cancer patients with K-ras and p53 mutations and their subtypes to the characteristics of the general population controls.

RESULTS

Smoking (adjusted odds ratio [aOR] = 2.0; 95% confidence interval [95%CI] = 0.9-4.3) and diabetes diagnosed 5 or more years before interview (aOR = 3.4; 95%CI = 1.3-8.8) were associated with pancreatic cancer patients positive for K-ras codon 12 mutations, but not with pancreatic cancer patients negative for K-ras codon 12 mutations. On the other hand, none of the examined risk factors were meaningfully related to patients with p53 mutations.

CONCLUSIONS

This study suggests that some recognized risk factors for pancreatic cancer may also be associated with K-ras codon 12 mutations. However, further large-scale studies are warranted.

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.

Meat and meat-mutagen intake and pancreatic cancer risk in the NIH-AARP cohort

Meat intake, particularly red meat, has been positively associated with pancreatic cancer in some epidemiologic studies. Detailed meat-cooking methods and related mutagens formed in meat cooked at high temperatures have not been evaluated prospectively as risk factors for this malignancy. We investigated the association between meat, meat-cooking methods, meat-mutagen intake, and exocrine pancreatic cancer in the NIH-American Association of Retired Persons (NIH-AARP) Diet and Health Study cohort of 537,302 individuals, aged 50 to 71 years, with complete baseline dietary data (1995-1996) ascertained from a food frequency questionnaire. A meat-cooking module was completed by 332,913 individuals 6 months after baseline. During 5 years of follow-up, 836 incident pancreatic cancer cases (555 men, 281 women) were identified. Four hundred and fifty-nine cases had complete meat module data. We used Cox proportional hazard models to calculate hazard ratios (HR) and 95% confidence intervals (CI). Total, red, and high-temperature cooked meat intake was positively associated with pancreatic cancer among men (fifth versus first quintile: HR, 1.41, 95% CI, 1.08-1.83, P trend = 0.001; HR, 1.42, 95% CI, 1.05-1.91, P trend = 0.01; and HR, 1.52, 95% CI, 1.12-2.06, P trend = 0.005, respectively), but not women. Men showed significant 50% increased risks for the highest tertile of grilled/barbecued and broiled meat and significant doubling of risk for the highest quintile of overall meat-mutagenic activity (P trends < 0.01). The fifth quintile of the heterocyclic amine, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline intake showed a significant 29% (P trend = 0.006) increased risk in men and women combined. These findings support the hypothesis that meat intake, particularly meat cooked at high temperatures and associated mutagens, may play a role in pancreatic cancer development.

Glutathione S-transferase gene polymorphisms and risk and survival of pancreatic cancer

BACKGROUND

Pancreatic cancer is a multifactorial disease with metastasis-prone and therapy-resistant nature. The authors hypothesized that genetic variants of glutathione S-transferase (GST) affect detoxification of carcinogens and anticancer agents in the human pancreas and, thus, the risk and survival of pancreatic cancer.

METHODS

Genotypes of GSTM1, GSTT1, and GSTP1 were determined in 352 patients with pancreatic ductal adenocarcinoma and in a control group of 315 healthy, non-Hispanic whites (frequency-matched by age and sex). Survival analysis was performed in a subset of 290 patients. Epidemiological and clinical information was obtained. A multiple unconditional logistic regression model, a Cox proportional hazards model, and log-rank tests were used for statistical analysis.

RESULTS

No significant main effects of any of 3 GST genes on the risk of pancreatic cancer were observed. Subgroup analysis showed that older individuals (aged >or=62 years) who carried the GSTP1*C ((105)Val-(114)Val) containing genotype tended to have a reduced risk compared with younger individuals who carried the non-*C genotype (for sex and pack-years of smoking, the adjusted odd ratio was 0.54; 95% confidence interval [95% CI], 0.29-1.02). In a survival analysis of 138 patients who received 5-flurorouracil, patients who carried the GSTP1*C containing genotype had a significantly longer survival than patients who carried the non-*C genotype (multivariate hazard ratio, 0.45; 95% CI, 0.22-0.94).

CONCLUSIONS

The GSTP1*C variant conferred a possible protective effect against pancreatic cancer in older individuals and a significant survival advantage in patients who received 5-florouracil. The current findings must be confirmed before further inferences can be made.

K-ras mutation and p16 and preproenkephalin promoter hypermethylation in plasma DNA of pancreatic cancer patients: in relation to cigarette smoking

OBJECTIVES

To examine the profiles of K-ras mutations and p16 and preproenkephalin (ppENK) promoter hypermethylation and their associations with cigarette smoking in pancreatic cancer patients.

METHODS

In plasma DNA of 83 patients with untreated primary pancreatic ductal adenocarcinoma, DNA hypermethylation was determined by methylation-specific polymerase chain reaction and K-ras codon 12 mutations by enriched-nested polymerase chain reaction followed by direct sequencing. Information on smoking exposure was collected by in-person interview. Pearson chi test and Fisher exact test were used in statistical analysis.

RESULTS

K-ras mutations, ppENK, and p16 promoter hypermethylation were detected in 32.5%, 29.3%, and 24.6% of the patients, respectively. Sixty-three percent (52/83) of patients exhibited at least one of the alterations. Smoking was associated with the presence of K-ras mutations (P = 0.003). A codon 12 G-to-A mutation was predominantly observed in regular smokers and in heavy smokers (pack-year of smoking > or =36). Smoking was not associated with p16 or ppENK hypermethylation.

CONCLUSIONS

These preliminary observations suggest that plasma DNA might be a useful surrogate in detecting genetic and epigenetic alterations of pancreatic cancer. The findings on the association between K-ras mutation and smoking were in consistency with previous studies. Further studies on environmental modulators of epigenetic changes in pancreatic cancer are warranted.

Pancreatic intraepithelial neoplasia and ductal adenocarcinoma induced by DMBA in mice

BACKGROUND

Pancreatic ductal adenocarcinoma has a poor long-term prognosis. Experimental models are necessary to understand not only its biologic behavior, but also the early pancreatic lesions known as pancreatic intraepithelial neoplasia (PanIN) and to develop new treatments. The aim of this study was to evaluate pancreatic carcinogenesis induced by 7,12-dimethyl-1,2-benzanthracene (DMBA) implantation in mice according to the PanIN classification system.

METHODS

Ninety male, Mus musculus, CF-1 mice underwent a median laparotomy and 1 mg of DMBA was implanted into the proximal pancreas held in place by a purse-string suture. Mice were killed after 30 and 60 days after which the excised pancreata were fixed in formalin, embedded in paraffin, and stained with hematoxylin-eosin for histologic analysis. The specimens were evaluated blind by 2 pathologists for the presence of the following histology: normal ducts, reactive hyperplasia, PanIN-1A, PanIN-1B, PanIN-2, and PanIN-3, and adenocarcinoma.

RESULTS

In the 30-day group, pathologic evaluation showed 4 (17%) reactive hyperplasia, 16 (67%) PanIN lesions, and 4 (17%) adenocarcinomas. In the 60-day group, there were 10 (27%) specimens with reactive hyperplasia, 13 (35%) with PanIN lesions, and 14 (38%) with adenocarcinomas. The difference between groups was statistically significant (P<.05). All pancreata with adenocarcinoma had concomitant PanIN lesions.

CONCLUSIONS

The DMBA experimental model in mice induces PanIN lesions and ductal adenocarcinoma that have similar histology to that of human pancreatic cancer. This model may be useful for study of pancreatic carcinogenesis, particularly the molecular progression of early pancreatic ductal lesions.

Low correspondence between K-ras mutations in pancreatic cancer tissue and detection of K-ras mutations in circulating DNA

OBJECTIVE

K-ras is the most frequently mutated gene in pancreatic cancer; reported rates range from 70% to 90%. The aim of this study was to evaluate the correspondence between K-ras mutations in pancreatic cancer tissue and in circulating DNA and the value of K-ras mutations as serological marker.

METHODS

The research was conducted in 30 patients with pancreatic cancer in whom both plasma and neoplastic tissues were available. Such research was extended to circulating DNA isolated from 40 patients with chronic pancreatitis. Mutations in codon 12 were examined by mutant allele-specific amplification method and by direct sequencing. Serum values of routinely used tumor markers such as carbohydrate antigen (Ca) 19.9, carcinoembryonic antigen, Ca 50, and Ca 242 have been tested in all the patients enrolled in this study.

RESULTS

K-ras mutations were detected in 70% of neoplastic tissue samples, but no mutated DNA resulted in circulating DNA samples. The 60% of patients with tissue K-ras mutation showed elevation of some tumor markers among Ca 19.9, carcinoembryonic antigen, Ca 50, and Ca 242. As a whole, these last showed low sensitivity (20%-56.67%) and specificity (56.67%-77.5%) when compared with chronic pancreatitis.

CONCLUSION

Over the years, there has been no change in the direction of an earlier diagnosis by serological markers, and also, these data indicate that K-ras mutation in serum is an unsatisfactory method for the detection in patients with pancreatic cancer as well as in patients with high risk of progression toward neoplastic pancreatic disease.

Prophylaktische Chirurgie des Pankreas

The goal of prophylactic surgery is to prevent malignant growth in patients with hereditary tumor predisposition. The pancreas presents as particularly challenging, due to the difficulty of operation and comparatively high risk of morbidity and even mortality. In addition, partial operative procedures and, more significantly, total resection lead to exocrine pancreas insufficiency and secondary diabetes, with grave consequences for the patient. Hereditary tumor predisposition syndromes that can result in pancreaticoduodenal endocrine tumors (PET) include multiple endocrine neoplasia type 1 syndrome and von Hippel-Lindau syndrome. As penetrance is maximally 70-80% and the 10-year survival rate over 80%, prophylactic pancreatic resection without evidence of a tumor is not indicated. However, prophylactic extension of a resection would be advised, should a PET be diagnosed. Patients predisposed to developing ductal pancreatic carcinoma (PC) are at risk of familial pancreatic cancer syndrome (FPC), hereditary pancreatitis, and other hereditary tumor predisposition syndromes such as Peutz-Jeghers syndrome and familial atypical multiple mole-melanoma syndrome. As the gene defect responsible for FPC has yet to be identified and the penetrance of PC in the other tumor predisposition syndromes is low or unknown, a prophylactic pancreatectomy based on today's knowledge is not indicated. Prophylactic extension of the resection is advisable should PC or high-grade PanIN lesions be diagnosed, as these patients often present with multifocal dysplasia and even carcinoma.

Gemcitabine treatment in patients with inoperable locally advanced/metastatic pancreatic cancer and prognostic factors

OBJECTIVE

Most patients with pancreatic cancer show an inoperable locally advanced/ metastatic tumour at the time of diagnosis. The present study was aimed at determining the prognostic factors in patients with advanced pancreatic carcinoma treated with gemcitabine.

MATERIAL AND METHODS

Sixty-seven unresectable or metastatic pancreatic cancer patients treated with gemcitabine were included in the study and a total of 258 cycles of treatment were applied.

RESULTS

The overall response rate was 5%. Thirty-one percent of the patients had stable disease, whereas progressive disease was seen in 49%. Clinical benefit response rate was 15%. The median duration of response was 7.3 months. Median progression-free survival was 3 months, while median overall survival was 9 months. Univariate analysis revealed that worse results were found in patients with performance status (PS) = 2, and in patients with primary tumour location in the body or tail of the pancreas (p<0.05). Multivariate analysis of data revealed that the most important factor was PS of the patient, as the patients with PS = 2 had worse results than the patients with PS = 0-1 (p<0.05).

CONCLUSIONS

Low PS is a negative predictive factor for the survival of patients with advanced pancreatic carcinoma treated with gemcitabine.

Differences in survival by histologic type of pancreatic cancer

OBJECTIVE

Although pancreatic cancer has an extremely high case fatality rate, little is known about differences in mortality by histologic types. We examined median survival and risk of mortality for endocrine pancreatic tumors and two types of exocrine tumors, adenocarcinomas, and mucinous tumors.

METHOD

This analysis included 35,276 pancreatic cancer cases reported to the nine population-based cancer registries participating in the Surveillance, Epidemiology, and End Results program from 1973 to 2000. Survival among cases with pancreatic adenocarcinomas, mucinous tumors, and endocrine tumors were compared using Kaplan-Meier plots. Comparative risks of mortality were evaluated using multivariate adjusted Cox regression models.

RESULTS

Endocrine pancreatic cancer cases had a median survival of 27 months compared with a median survival of 4 months for adenocarcinoma and mucinous tumor cases. Compared with adenocarcinoma cases, endocrine tumor cases had a 0.28-fold lower risk of mortality [95% confidence interval (95% CI), 0.26-0.30], and mucinous tumor cases had a 0.88-fold lower risk (95% CI, 0.84-0.91). These results were similar for men and women. Within histologic types, advanced tumor stage, older diagnosis age, surgery, and Black race were associated with increased risks of mortality, whereas female sex and more recent year of diagnosis were associated with decreased risks.

CONCLUSION

This study confirms the clinical observation that patients with endocrine pancreatic cancer survive longer than patients with exocrine tumors. A better understanding of these differences could contribute to identifying the underlying causes of pancreatic cancer and to improving survival rates across all histologic types.

Pancreatic cancer epidemiology

Carcinoma of the exocrine pancreas remains a challenging disease mainly due to advanced stage diagnosis, the early systemic dissemination, aggressive local tumor progression, and subsequent short patient survival. Thus, assessment of incidence markers instead of prevalence indicators is recommended because the time between diagnosis and death is usually very short. Investigations to date have led to the discovery of many rare genes and environmental factors that contribute to pancreatic cancer. However, common genes involved in genetic polymorphisms, and specific risk factors have not been identified. Furthermore, the role of gene-environment interactions on the tumorogenesis and progression of pancreatic cancer need to be further investigated. Given current therapeutic modalities, only early detection of cancer of the pancreas, followed by surgical resection, offers the possibility of lengthening survival time.

Genotoxicity of tobacco smoke and tobacco smoke condensate: a review

This report reviews the literature on the genotoxicity of mainstream tobacco smoke and cigarette smoke condensate (CSC) published since 1985. CSC is genotoxic in nearly all systems in which it has been tested, with the base/neutral fractions being the most mutagenic. In rodents, cigarette smoke induces sister chromatid exchanges (SCEs) and micronuclei in bone marrow and lung cells. In humans, newborns of smoking mothers have elevated frequencies of HPRT mutants, translocations, and DNA strand breaks. Sperm of smokers have elevated frequencies of aneuploidy, DNA adducts, strand breaks, and oxidative damage. Smoking also produces mutagenic cervical mucus, micronuclei in cervical epithelial cells, and genotoxic amniotic fluid. These data suggest that tobacco smoke may be a human germ-cell mutagen. Tobacco smoke produces mutagenic urine, and it is a human somatic-cell mutagen, producing HPRT mutations, SCEs, microsatellite instability, and DNA damage in a variety of tissues. Of the 11 organ sites at which smoking causes cancer in humans, smoking-associated genotoxic effects have been found in all eight that have been examined thus far: oral/nasal, esophagus, pharynx/larynx, lung, pancreas, myeoloid organs, bladder/ureter, uterine cervix. Lung tumors of smokers contain a high frequency and unique spectrum of TP53 and KRAS mutations, reflective of the PAH (and possibly other) compounds in the smoke. Further studies are needed to clarify the modulation of the genotoxicity of tobacco smoke by various genetic polymorphisms. These data support a model of tobacco smoke carcinogenesis in which the components of tobacco smoke induce mutations that accumulate in a field of tissue that, through selection, drive the carcinogenic process. Most of the data reviewed here are from studies of human smokers. Thus, their relevance to humans cannot be denied, and their explanatory powers not easily dismissed. Tobacco smoke is now the most extreme example of a systemic human mutagen.

Alcohol consumption and smoking status: the role of smoking cessation

Cigarette smoking is common among persons with alcohol dependence or abuse with as many as 80% of persons who are alcohol dependent also being smokers. Not only is smoking common in persons with heavy alcohol consumption, but also nicotine dependence appears more severe in smokers with a history of alcohol dependence. This combined exposure to both tobacco smoke and alcohol results in major health consequences including additive risks for some diseases such as head and neck cancers. Although modest alcohol consumption has some positive health benefits, smoking typically negates these benefits. The cellular mechanisms impacted by combined smoking and alcohol exposure are poorly understood, but molecular epidemiology approaches are providing insights regarding the importance of effects on oxidant/antioxidant pathways and on metabolic pathways involving the cytochrome P450 system. Given the prevalence of smoking in the alcohol dependent population, smoking cessation in this group has the potential for tremendous impact. In recent years, smoking cessation approaches have been initiated in this population, but much work remains in order to define the optimal smoking cessation strategies for persons in alcohol treatment programs.

Characterization of risk for general population exposure to perfluorooctanoate

Perfluorooctanoate (PFOA), an environmentally and metabolically stable perfluorinated carboxylic acid, has been detected in the serum of children, adults and the elderly from the United States with the upper bound of the 95th percentile estimate in the range of 0.011-0.014 microg/mL (ppm). In this risk characterization, margins of exposure (MOE), which can provide a realistic perspective on potential for human risk, were determined by comparison of general population serum PFOA concentrations with serum concentrations from toxicological studies that are associated with the lower 95% confidence limit of a modeled 10 percent response or incidence level (LBMIC(10)) using USEPA BMDS software. The LBMIC(10) was estimated using surrogate data from other studies or pharmacokinetic relationships if serum PFOA data were not available. Modeled dose-responses (with resulting LBMIC(10) values) included post-natal effects in rats (29 microg/mL), liver-weight increase (23 microg/mL), and body-weight change (60 microg/mL) in rats and monkeys, and incidence of Leydig cell adenoma (125 microg/mL) in rats. MOE values based on the upper bound 95th percentile population serum PFOA concentration were large, ranging from 1600 (liver-weight increase) to 8900 (Leydig cell adenoma). These MOE values represent substantial protection of children, adults, and the elderly.