A prospective study of aspirin use and the risk of pancreatic cancer in women

Risk Factors for Pancreatic Cancer: Emerging Role of Viral Hepatitis

Pancreatic cancer is one of the most aggressive malignant neoplastic diseases. The incidence and mortality rates of this disease vary depending on geographical area, which might be explained by the different exposure to risk factors. To improve the prognosis of patients with pancreatic cancer, different approaches are needed for an earlier diagnosis. Identification of risk factors and implementation of screening strategies are essential for a better prognosis. Currently, the risk factors for pancreatic cancer fall into two broad categories, namely extrinsic and intrinsic factors. Extrinsic factors include alcohol consumption, smoking, a diet rich in saturated fats, and viral infections such as chronic infection with hepatitis B and C viruses. The pathophysiological mechanisms explaining how these hepatotropic viruses contribute to the development of pancreatic cancer are not fully elucidated. The common origin of hepatocytes and pancreatic cells in the multipotent endodermal cells, the common origin of the blood vessels and biliary ducts of the pancreas and the liver, or chronic inflammatory changes may be involved in this interaction. A careful monitoring of patients with viral liver infections may contribute to the early diagnosis of pancreatic cancer and improve the prognosis of these patients.

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

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

Cytotoxic and Apoptotic Effects of Celecoxib and Topotecan on AGS and HEK 293 Cell Lines

PURPOSE

This study is aimed to assess the anti-cancer effects of Celecoxib and topotecan against Human Gastric cancer cell line (AGS) in comparison to the control in an in-vitro study.

METHODS

In this experimental study, Celecoxib and topotecan was prepared at concentrations of 500, 250, 125, 62.5, 31.2, 15.6 and 7.8 mg/ml. The effect of celecoxib and topotecan separately and in mixed form were investigated on AGS and normal HEK cells. To investigate the cell survival, MTT method was used to study the pathway of apoptosis using flowcytometry and Caspase kits based on colorimetric. Finally, one-way ANOVA and t-test were used to analyze the data.

RESULTS

The results of this study indicated that Celecoxib was cytotoxic against AGS and HEK cell lines. The topotecan indicated a significant cytotoxicity against AGS cells and was not toxic against HEK cell line. Our results indicated that Celecoxib and topotecan have synergist effects against AGS and HEK cell lines and were more effective than separate celecoxib or topotecan.

CONCLUSION

The mixture of clecoxib and topotecan was more effective than celecoxib and topotecan in separate form. Our results indicated that use mixed forms of treatments can cause excellent therapeutic effects and can cause less side effects.

The Epidemiology of Pancreatic Cancer and the Association With Acetylsalicylic Acid in the United States: A Population-Based Study

OBJECTIVES

Pancreatic cancer (PaC) is the third leading cause of cancer-related death in the United States. Multiple studies have investigated the epidemiology and the association between PaC and acetylsalicylic acid (ASA) use, revealing mixed results. Using a large database, we sought to investigate the epidemiology of PaC.

METHODS

Using a commercial database (Explorys Inc, Cleveland, Ohio), which includes electronic health record data from 26 major integrated US health care systems, all patients 18 years and older diagnosed with PaC for 5 years were identified based on Systematized Nomenclature Of Medicine-Clinical Terms. We determined the prevalence of PaC and the potential associated factors using univariable and multivariable analysis.

RESULTS

Of the 32,970,850 individuals, we identified 30,250 individuals with PaC with an overall prevalence of 0.08%. Individuals with PaC were more likely to be males, seniors (age, >65 years), and White, compared with patients without PaC. In subgroup analysis of chronic pancreatitis, individuals on ASA, individuals >65 years, White, and White males were less likely to have PaC, and non-White females were more likely to have PaC.

CONCLUSIONS

This is the largest population-based study evaluating the epidemiology of PaC. We observed a protective association of ASA on a subgroup of patients with PaC and chronic pancreatitis.

Aspirin use and pancreatic cancer risk: A systematic review of observational studies

OBJECTIVES

Although there is evidence that aspirin might be able to prevent pancreatic cancer, the findings have been inconsistent. In this paper, we conducted a meta-analysis of observational studies to examine the relationship between aspirin use and the risk of pancreatic cancer.

METHODS

We identified potential studies by searching the MEDLINE, EMBASE, and Wangfang (Chinese database) database (from 1967 to March 2017) and by reviewing the bibliography of relevant publications. Random effects model was used to calculate odds ratio (OR) and 95% confidence interval. The Cochran Q statistic (significance level at P < .1) was used to assess heterogeneity in this study. The author adopted weighted regression method of Egger to assessed publication bias.

RESULTS

A total of 12 studies involving 4748 pancreatic cancer cases, were included in the meta-analysis. The study reflected that there was no signification association between aspirin use and mortality risk of pancreatic cancer. Aspirin use might reduce the incidence of pancreatic cancer. Specifically, there was a high signification association between frequent aspirin use and reduced pancreatic cancer incidence, without heterogeneity. In addition, there was a high signification association between duration of aspirin use more than 5 years and reduced pancreatic cancer incidence, without obvious heterogeneity among the original studies.

CONCLUSIONS

In summary, this meta-analysis suggested that the aspirin use might be negatively related to the incidence risk of pancreatic cancer. Specifically, the frequency and duration of aspirin use might play an important role in decreasing the incidence of pancreatic cancer.

Regular Use of Aspirin or Non-Aspirin Nonsteroidal Anti-Inflammatory Drugs Is Not Associated With Risk of Incident Pancreatic Cancer in Two Large Cohort Studies

BACKGROUND & AIMS

Use of aspirin and/or non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of several cancers, but it is not clear if use of these drugs is associated with risk of pancreatic cancer.

METHODS

We evaluated aspirin and non-aspirin NSAID use and risk of pancreatic adenocarcinoma in 141,940 participants from the Health Professionals Follow-up Study and Nurses' Health Study using multivariable-adjusted Cox proportional hazards regression. We considered several exposure classifications to model differing lag times between NSAID exposure and cancer development. We also conducted a nested case-control study of participants from 3 prospective cohorts using conditional logistic regression to evaluate pre-diagnosis levels of plasma salicylurate, a major metabolite of aspirin, in 396 pancreatic cancer cases and 784 matched individuals without pancreatic cancer (controls).

RESULTS

In the prospective cohort study, 1122 participants developed pancreatic adenocarcinoma over 4.2 million person-years. Use of aspirin or non-aspirin NSAIDs was not associated with pancreatic cancer risk, even after considering several latency exposure classifications. In a pre-planned subgroup analysis, regular aspirin use was associated with reduced pancreatic cancer risk among participants with diabetes (relative risk, 0.71; 95% CI, 0.54-0.94). In the nested case-control study, pre-diagnosis levels of salicylurate were not associated with pancreatic cancer risk (odds ratio, 1.08; 95% CI, 0.72-1.61; Ptrend 0.81; comparing participants in the highest quintile with those in the lowest quintile of plasma salicylurate).

CONCLUSIONS

Regular aspirin or non-aspirin NSAID use was not associated with future risk of pancreatic cancer in participants from several large prospective cohort studies. A possible reduction in risk for pancreatic cancer among people with diabetes who regularly use aspirin should be further examined in preclinical and human studies.

Novel 1,2,3‐Triazole‐Functionalized 1,2‐Benzothiazine 1,1‐Dioxide Derivatives: Regioselective Synthesis, Biological Evaluation and Docking Studies

A series of novel 1,2‐benzothiazine‐1,1‐dioxide derivatives (Z)‐3‐hydroxy‐1‐(4‐hydroxy‐2‐methyl‐1,1‐dioxido‐2H‐benzo[e][1, 2]thiazin‐3‐yl)‐3‐phenyl substituted prop‐2‐en‐1‐one (6 a‐d) were synthesized starting from sodium salt of saccharin 1 in series of steps via 3‐acetyl‐2‐methyl‐1,1‐dioxido‐2H‐benzo[e][1, 2]thiazin‐4‐yl substituted benzoates (5 a‐d). Compound 6 e was obtained alternately from 1‐(4‐Hydroxy‐2‐methyl‐1,1‐dioxo‐1,2‐dihydro‐1λ6‐benzo[e][1, 2]thiazin‐3‐yl)‐ethanone (4). Compounds 6 a‐e were further reacted with aromatic azides to form (4‐hydroxy‐2‐methyl‐1,1‐dioxido‐2H‐benzo[e][1, 2]thiazin‐3‐yl)(1‐substitutedphenyl)‐5‐ substituted pheny or methyl‐1H‐1,2,3‐triazol‐4‐yl)methanone derivatives (7 a‐o) by regioselective cyclization. All the compounds were evaluated for anti‐inflammatory and anti‐cancer activities. Compounds 5 a‐b, 6 a‐b, 7 a, 7 c‐d, 7 i and 7 k‐l which showed significant anti‐inflammatory activity at micro molar concentration have been identified. Also screened for cytotoxic activity against four human cancer cells and one normal cell such as prostate cancer (PC‐3), breast adenocarcinoma (MDA‐MB‐231), liver hepatocellular carcinoma (Hep G2), cervical cancer (HeLa) and normal umbilical vein endothelial cell (HUVEC). Compounds 6 a, 7 g, 7 h and 7 k have been identified as promising candidates. Further, anti‐inflammatory activity is also validated by docking studies and compounds 5 a, 5 b and 7 d found to show good interactions when docked with IL‐1β signaling complex.

Exclusive and Combined Use of Statins and Aspirin and the Risk of Pancreatic Cancer: a Case-Control Study

Data on the association between aspirin and statin use and Pancreatic Ductal AdenoCarcinoma (PDAC) risk are conflicting. These drugs are often co-prescribed, but no studies evaluated the potential combined or confounding effect of the two at the same time. We aimed to investigate the association between aspirin and statin exclusive and combined use and PDAC occurrence. Data on environmental factors, family and medical history were screened in a case-control study. PDAC cases were matched to controls for age and gender. Power calculation performed ahead. Odds ratios (OR) and 95% confidence intervals(CI) were obtained from multivariable logistic regression analysis. In 408 PDAC patients and 816 matched controls, overall statin (OR 0.61; 95%CI,0.43-0.88), but not aspirin use was associated to reduced PDAC risk. Compared to non-users, exclusive statin (OR 0.51; 95%CI,0.32-0.80) and exclusive aspirin users (OR 0.64; 95%CI,0.40-1.01) had reduced PDAC risk. Concomitant statin and aspirin use did not further reduce the risk compared with statin use alone and no interaction was evident. Statin protective association was dose-dependent, and consistent in most subgroups, being stronger in smokers, elderly, obese and non-diabetic patients. The present study suggests that statin use is associated to reduced PDAC risk, supporting a chemopreventive action of statins on PDAC.

[Inflammation and Cancer Development in Pancreatic and Biliary Tract Cancer]

Chronic inflammation has been known to be a risk for many kinds of cancers, including pancreatic and biliary tract cancer. Recently, inflammatory process has emerged as a key mediator of cancer development and progression. Many efforts with experimental results have been given to identify the underlying mechanisms that contribute to inflammation-induced tumorigenesis. Diverse inflammatory pathways have been investigated and inhibitors for inflammation-related signaling pathways have been developed for cancer treatment. This review will summarize recent outcomes about this distinctive process in pancreatic and biliary tract cancer. Taking this evidence into consideration, modulation of inflammatory process will provide useful options for pancreatic and biliary tract cancer treatment.

The Role of Common Pharmaceutical Agents on the Prevention and Treatment of Pancreatic Cancer

Survival from pancreatic cancer remains poor. Conventional treatment has resulted in only marginal improvements in survival compared with survival in the previous several decades. Thus, considerable interest has emerged regarding the potential use of common pharmaceutical agents as chemopreventative and chemotherapeutic options. Aspirin, metformin, statins, β-blockers, and bisphosphonates have biologically plausible mechanisms to inhibit pancreatic neoplasia, whereas dipeptidyl-peptidase 4 inhibitors may promote it. Regardless, real-world epidemiological data remain inconclusive. This review examines the hypotheses, evidence, and current state of the literature for each of these medications and their potential roles in the prevention and treatment of pancreatic cancer.

Aspirin in pancreatic cancer: chemopreventive effects and therapeutic potentials

Pancreatic cancer is one of the most aggressive malignancies with dismal prognosis. Recently, aspirin has been found to be an effective chemopreventive agent for many solid tumors. However, the function of aspirin use in pancreatic cancer largely remains unknown. We herein argued that aspirin could also lower the risk of pancreatic cancer. Importantly, aspirin assumes pleiotropic effects by targeting multiple molecules. It could further target the unique tumor biology of pancreatic cancer and modify the cancer microenvironment, thus showing remarkable therapeutic potentials. Besides, aspirin could reverse the chemoradiation resistance by repressing tumor repopulation and exert synergistic potentials with metformin on pancreatic cancer chemoprevention. Moreover, aspirin secondarily benefits pancreatic cancer patients through modestly reducing cancer pain and the risk of venous thromboembolism. Furthermore, new aspirin derivatives and delivery systems might help to improve risk-to-benefit ratio. In brief, aspirin is a promising chemopreventive agent and exerts significant therapeutic potentials in pancreatic cancer.

Aspirin might reduce the incidence of pancreatic cancer: A meta-analysis of observational studies

Although there is evidence that non-steroidal anti-inflammatory drugs (NSAIDs) might be able to prevent pancreatic cancer, the findings from epidemiological studies have been inconsistent. In this paper, we conducted a meta-analysis of observational studies to examine this possibility. We searched PubMed and Embase for observational (cohort or case-control) studies examining the consumption of aspirin and other NSAIDs and the incidence of or mortality rates associated with pancreatic cancer. Twelve studies including approximately 258,000 participants in total were analysed. The administration of aspirin significantly reduced the incidence of pancreatic cancer (8 studies; odds ratio (OR) = 0.77; 95% confidence interval (CI) = 0.62 to 0.96; I(2) = 74.2%) but not the mortality associated with it (2 studies; OR = 0.94; 95% CI = 0.73 to 1.22). Specifically, frequent aspirin use was associated with reduced pancreatic cancer incidence (OR = 0.57; 95% CI = 0.39 to 0.83 for high frequency; OR = 0.57; 95% CI = 0.38 to 0.84 for medium frequency). The summary ORs regarding the incidence of pancreatic cancer and either non-aspirin NSAIDs use (OR = 1.08; 95% CI = 0.90 to 1.31) or overall NSAIDs use (OR = 0.97; 95% CI = 0.86 to 1.10) were not significant. In conclusion, aspirin use might reduce the incidence of pancreatic cancer; however, this finding should be interpreted with caution because of study heterogeneity.

Dissecting the Potential Interplay of DEK Functions in Inflammation and Cancer

There is a long-standing correlation between inflammation, inflammatory cell signaling pathways, and tumor formation. Understanding the mechanisms behind inflammation-driven tumorigenesis is of great research and clinical importance. Although not entirely understood, these mechanisms include a complex interaction between the immune system and the damaged epithelium that is mediated by an array of molecular signals of inflammation—including reactive oxygen species (ROS), cytokines, and NFκB signaling—that are also oncogenic. Here, we discuss the association of the unique DEK protein with these processes. Specifically, we address the role of DEK in chronic inflammation via viral infections and autoimmune diseases, the overexpression and oncogenic activity of DEK in cancers, and DEK-mediated regulation of NFκB signaling. Combined, evidence suggests that DEK may play a complex, multidimensional role in chronic inflammation and subsequent tumorigenesis.

Ferulic acid combined with aspirin demonstrates chemopreventive potential towards pancreatic cancer when delivered using chitosan-coated solid-lipid nanoparticles

BACKGROUND

The overall goal of this study was to demonstrate potential chemopreventive effects of ferulic acid (FA), an antioxidant, combined with aspirin (ASP), a commonly used anti-inflammatory drug for pancreatic cancer chemoprevention, using a novel chitosan-coated solid lipid nanoparticles (c-SLN) drug delivery system encapsulating FA and ASP.

RESULTS

Our formulation optimization results showed that c-SLNs of FA and ASP exhibited appropriate initial particle sizes in range of 183 ± 46 and 229 ± 67 nm, encapsulation efficiency of 80 and 78 %, and zeta potential of 39.1 and 50.3 mV, respectively. In vitro studies were conducted to measure growth inhibition and degree of apoptotic cell death induced by either FA or ASP alone or in combination. Cell viability studies demonstrated combinations of low doses of free FA (200 µM) and ASP (1 mM) significantly reduced cell viability by 45 and 60 % in human pancreatic cancer cells MIA PaCa-2 and Panc-1, respectively. However, when encapsulated within c-SLNs, a 5- and 40-fold decreases in dose of FA (40 µM) and ASP (25 µM) was observed which was significant. Furthermore, increased apoptosis of 35 and 31 % was observed in MIA PaCa-2 and Panc-1 cells, respectively. In vivo studies using oral administration of combinations of 75 and 25 mg/kg of FA and ASP c-SLNs to MIA PaCa-2 pancreatic tumor xenograft mice model suppressed the growth of the tumor by 45 % compared to control, although this was not statistically significant. In addition, the immunohistochemical analysis of tumor tissue showed significant decrease in expression of proliferation proteins PCNA and MKI67, and also increased expression of apoptotic proteins p-RB, p21, and p-ERK1/2 indicating the pro-apoptotic role of the regimen.

CONCLUSION

Combination of FA and ASP delivered via a novel nanotechnology-based c-SLN formulation demonstrates potential for pancreatic cancer chemoprevention and could be a promising area for future studies.

Aspirin counteracts cancer stem cell features, desmoplasia and gemcitabine resistance in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is characterized by an extremely poor prognosis. An inflammatory microenvironment triggers the pronounced desmoplasia, the selection of cancer stem-like cells (CSCs) and therapy resistance. The anti-inflammatory drug aspirin is suggested to lower the risk for PDA and to improve the treatment, although available results are conflicting and the effect of aspirin to CSC characteristics and desmoplasia in PDA has not yet been investigated. We characterized the influence of aspirin on CSC features, stromal reactions and gemcitabine resistance. Four established and 3 primary PDA cell lines, non-malignant cells, 3 patient tumor-derived CSC-enriched spheroidal cultures and tissues from patients who did or did not receive aspirin before surgery were analyzed using MTT assays, flow cytometry, colony and spheroid formation assays, Western blot analysis, antibody protein arrays, electrophoretic mobility shift assays (EMSAs), immunohistochemistry and in vivo xenotransplantation. Aspirin significantly induced apoptosis and reduced the viability, self-renewal potential, and expression of proteins involved in inflammation and stem cell signaling. Aspirin also reduced the growth and invasion of tumors in vivo, and it significantly prolonged the survival of mice with orthotopic pancreatic xenografts in combination with gemcitabine. This was associated with a decreased expression of markers for progression, inflammation and desmoplasia. These findings were confirmed in tissue samples obtained from patients who had or had not taken aspirin before surgery. Importantly, aspirin sensitized cells that were resistant to gemcitabine and thereby enhanced the therapeutic efficacy. Aspirin showed no obvious toxic effects on normal cells, chick embryos or mice. These results highlight aspirin as an effective, inexpensive and well-tolerated co-treatment to target inflammation, desmoplasia and CSC features PDA.

Elevation of circulating branched-chain amino acids is an early event in human pancreatic adenocarcinoma development

Most patients with pancreatic ductal adenocarcinoma (PDAC) are diagnosed with advanced disease and survive less than 12 months. PDAC has been linked with obesity and glucose intolerance, but whether changes in circulating metabolites are associated with early cancer progression is unknown. To better understand metabolic derangements associated with early disease, we profiled metabolites in prediagnostic plasma from individuals with pancreatic cancer (cases) and matched controls from four prospective cohort studies. We find that elevated plasma levels of branched-chain amino acids (BCAAs) are associated with a greater than twofold increased risk of future pancreatic cancer diagnosis. This elevated risk was independent of known predisposing factors, with the strongest association observed among subjects with samples collected 2 to 5 years before diagnosis, when occult disease is probably present. We show that plasma BCAAs are also elevated in mice with early-stage pancreatic cancers driven by mutant Kras expression but not in mice with Kras-driven tumors in other tissues, and that breakdown of tissue protein accounts for the increase in plasma BCAAs that accompanies early-stage disease. Together, these findings suggest that increased whole-body protein breakdown is an early event in development of PDAC.

Chronic Pancreatitis and Pancreatic Cancer

BACKGROUND

Pancreatic cancer (PC) is one of the most lethal diseases with an incidence rate almost equal to the rate of mortality. Chronic pancreatitis (CP) is a common chronic inflammatory disease of unknown etiology that affects the pancreas. Epidemiological studies have identified CP to be a major risk factor for PC.

SUMMARY

A greater understanding of the molecular mechanisms linking CP and PC has identified several common pathways that provide targets for future interventions. This article reviews those components in the CP-PC connection, including the role of macrophages, the maintenance of genome stability, cytokines, and other nodal factors such as nuclear factor kappa B, COX-2 and reactive oxygen species.

KEY MESSAGE

The molecular mechanisms that underlie CP and PC provide novel targets for future therapies for PC.

PRACTICAL IMPLICATIONS

The stromal-desmoplastic reaction plays an important role in initiating and sustaining chronic inflammation and tumor progression. Recently, two targeted anti-tumor agents, erlotinib and nab-paclitaxel, have shown promising therapeutic efficacy. Notably, both these agents target components (EGFR and SPARC) within the inflammatory stroma surrounding malignant cells, underscoring the importance of inflammation in pancreatic carcinogenesis. Identifying the common pathways linking CP and PC may help uncover additional novel targets for future therapies.

Case-control study of aspirin use and risk of pancreatic cancer

BACKGROUND

Pancreas-cancer prognosis is dismal, with 5-year survival less than 5%. Significant relationships between aspirin use and decreased pancreas-cancer incidence and mortality have been shown in four of 13 studies.

METHODS

To evaluate further a possible association between aspirin use and risk of pancreatic cancer, we used data from a population-based Connecticut study conducted from January 2005 to August 2009, of 362 pancreas-cancer cases frequency matched to 690 randomly sampled controls.

RESULTS

Overall, regular use of aspirin was associated with reduced risk of pancreatic cancer [odds ratio (OR), 0.52; 95% confidence interval (CI), 0.39-0.69]. Increments of decreasing risk of pancreatic cancer were observed for each year of low-dose or regular-dose aspirin use (OR, 0.94; 95% CI, 0.91-0.98 and OR, 0.98; 95% CI, 0.96-1.01, respectively) and for increasing years in the past that low-dose or regular-dose aspirin use had started (OR, 0.95; 95% CI, 0.92-0.99 and OR, 0.98; 95% CI, 0.96-1.00, respectively). Reduced risk of pancreatic cancer was seen in most categories of calendar time period of aspirin use, for both low-dose aspirin and regular-dose aspirin use. Relative to continuing use at the time of interview, termination of aspirin use within 2 years of interview was associated with increased risk of pancreatic cancer (OR, 3.24; 95% CI, 1.58-6.65).

CONCLUSIONS

Our results provide some support that a daily aspirin regimen may reduce risk of developing pancreatic cancer.

IMPACT

Long-term aspirin use has benefits for both cardiovascular disease and cancer, but appreciable bleeding complications that necessitate risk-benefit analysis for individual applications.

Investigating the synergistic interaction of diabetes, tobacco smoking, alcohol consumption, and hypercholesterolemia on the risk of pancreatic cancer: a case-control study in Italy

The aims of the present research are to investigate the possible predictors of pancreatic cancer, in particular smoking status, alcohol consumption, hypercholesterolemia, and diabetes mellitus, in patients with histologically confirmed pancreatic carcinoma and to examine the synergism between risk factors. A case-control study (80 patients and 392 controls) was conducted at the Teaching Hospital “Agostino Gemelli” in Rome. A conditional logistic regression was used for the statistical analysis and results were presented as odds ratio (OR) and 95% confidence intervals (95% CI). We also investigated the possible interactions between risk factors and calculated the synergism index (SI). The multivariate analysis revealed that hypercholesterolemia and alcohol consumption resulted in important risk factors for pancreatic cancer even after the adjustment for all variables (OR: 5.05, 95% CI: 2.94–8.66; OR: 2.25, 95% CI: 1.30–3.89, resp.). Interestingly, important synergistic interactions between risk factors were found, especially between ever smoking status and alcohol consumptions (SI = 17.61) as well as alcohol consumption and diabetes (SI = 17.77). In conclusion, the study confirms that hypercholesterolemia and alcohol consumption represent significant and independent risk factors for pancreatic cancer. Moreover, there is evidence of synergistic interaction between diabetes and lifestyle factors (drinking alcohol and eating fatty foods).

Inflammation to cancer: The molecular biology in the pancreas (Review)

Inflammatory responses are known to be correlated with cancer initiation and progression, and exploration of the route from inflammation to cancer makes a great contribution in elucidating the mechanisms underlying cancer development. Pancreatic cancer (PC) is a lethal disease with a low radical-resection rate and a poor prognosis. As chronic pancreatitis is considered to be a significant etiological factor for PC development, the current review aims to describe the molecular pathways from inflammation to pancreatic carcinogenesis, in support of the strategies for the prevention, diagnosis and treatment of PC.

High-dose aspirin consumption contributes to decreased risk for pancreatic cancer in a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to analyze the association between aspirin intake and its effect for chemoprevention of pancreatic cancer incidence by using a meta-analysis method.

METHODS

The databases of MEDLINE, EMBASE, and Wangfang (Chinese database) were retrieved to identify eligible studies. Odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model.

RESULTS

A total of 10 studies (4 case-control studies, 5 prospective cohort studies, and 1 randomized controlled trial) with 7,252 cases of pancreatic cancer and more than 120,0000 healthy control subjects were enrolled in the studies. Pooled analyses showed that high-dose aspirin intake was marginally associated with decreased risk for pancreatic cancer for overall analysis (OR, 0.88; 95% CI, 0.76-1.01) as well as for both cohort and case-control studies (OR, 0.70; 95% CI, 0.54-1.16, for the cohort studies; OR, 0.82; 95% CI, 0.62-1.02, for the case-control studies), without between-study heterogeneity. Stratified analysis for Americans showed a similar result (OR, 0.82; 95% CI, 0.65-1.02). In contrast, our study inferred that low-dose aspirin intake was not associated with risk for pancreatic cancer for the total and subgroup analyses.

CONCLUSIONS

In summary, our study indicated that high-dose aspirin, rather than low-dose aspirin, might be associated with decreased risk for pancreatic cancer, especially for Americans.

A novel combinatorial nanotechnology-based oral chemopreventive regimen demonstrates significant suppression of pancreatic cancer neoplastic lesions

Pancreatic cancer is a deadly disease killing 37,000 Americans each year. Despite two decades of research on treatment options, the chances of survival are still less than 5% upon diagnosis. Recently, chemopreventive strategies have gained considerable attention as an alternative to treatment. We have previously shown significant in vitro chemopreventive effects with low-dose combinations of aspirin, curcumin, and sulforaphane (ACS) on pancreatic cancer cell lines. Here, we report the results of 24-week chemopreventive study with the oral administration of ACS combinations on the N-nitrosobis (2-oxopropyl) amine (BOP)-treated Syrian golden hamster model to suppress the progression of pancreatic intraepithelial neoplasms (PanIN) using unmodified (free drug) combinations of ACS, and nanoencapsulated (solid lipid nanoparticles; SLN) combinations of aspirin, curcumin, and free sulforaphane. The use of three different doses (low, medium, and high) of unmodified ACS combinations exhibited reduction in tumor incidence by 18%, 50%, and 68.7% respectively; whereas the modified nanoencapsulated ACS regimens reduced tumor incidence by 33%, 67%, and 75%, respectively, at 10 times lower dose compared with the free drug combinations. Similarly, although the unmodified free ACS showed a notable reduction in cell proliferation, the SLN encapsulated ACS regimens showed significant reduction in cell proliferation at 6.3%, 58.6%, and 72.8% as evidenced by proliferating cell nuclear antigen expression. Cell apoptotic indices were also upregulated by 1.5, 2.8, and 3.2 times, respectively, compared with BOP control. These studies provide a proof-of-concept for the use of an oral, low-dose, nanotechnology-based combinatorial regimen for the long-term chemoprevention of pancreatic cancer.

Impact of non-steroidal anti-inflammatory drugs on gastrointestinal cancers: current state-of-the science

Growing evidence from epidemiologic and preclinical studies suggests that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of gastrointestinal (GI) cancers, including esophageal, gastric, pancreatic, colorectal cancer, and hepatocellular carcinoma. However, there is also evidence indicating the absence of this benefit. The exact mechanism of NSAIDs' action on GI tumors is not known. Although some studies have suggested inhibition of carcinogenesis by NSAIDs through suppression effect on inflammation-associated cyclooxygenase-2 (COX-2) expression, other studies have suggested COX-2-independent mechanisms. Herein, we summarize the current state of-the-science regarding NSAID benefit for patients with GI cancers.

Chronic pancreatitis: a path to pancreatic cancer

Chronic pancreatitis predisposes to pancreatic cancer development and both diseases share a common etiology. A central role has been proposed for the digestive enzyme-secreting acinar cell that can undergo ductal metaplasia in the inflammatory environment of pancreatitis. This metaplastic change is now a recognised precursor of pancreatic cancer. Inflammatory molecules also foster tumour growth through autocrine and paracrine effects in the epithelium and the stroma. These insights have raised new opportunities such as the manipulation of inflammation as a preventive and/or therapeutic strategy for pancreatic cancer. Finally, we address the need for an in-depth study of the pancreatic acinar cells.

Involvement of inflammatory factors in pancreatic carcinogenesis and preventive effects of anti-inflammatory agents

Chronic inflammation is known to be a risk for many cancers, including pancreatic cancer. Heavy alcohol drinking and cigarette smoking are major causes of pancreatitis, and epidemiological studies have shown that smoking and chronic pancreatitis are risk factors for pancreatic cancer. Meanwhile, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are elevated in pancreatitis and pancreatic cancer tissues in humans and in animal models. Selective inhibitors of iNOS and COX-2 suppress pancreatic cancer development in a chemical carcinogenesis model of hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). In addition, hyperlipidemia, obesity, and type II diabetes are also suggested to be associated with chronic inflammation in the pancreas and involved in pancreatic cancer development. We have shown that a high-fat diet increased pancreatic cancer development in BOP-treated hamsters, along with aggravation of hyperlipidemia, severe fatty infiltration, and increased expression of adipokines and inflammatory factors in the pancreas. Of note, fatty pancreas has been observed in obese and/or diabetic cases in humans. Preventive effects of anti-hyperlipidemic/anti-diabetic agents on pancreatic cancer have also been shown in humans and animals. Taking this evidence into consideration, modulation of inflammatory factors by anti-inflammatory agents will provide useful data for prevention of pancreatic cancer.

Inhibition of pancreatic intraepithelial neoplasia progression to carcinoma by nitric oxide-releasing aspirin in p48(Cre/+)-LSL-Kras(G12D/+) mice

Nitric oxide-releasing aspirin (NO-aspirin) represents a novel class of promising chemopreventive agents. Unlike conventional nonsteroidal anti-inflammatory drugs, NO-aspirin seems to be free of adverse effects while retaining the beneficial activities of its parent compound. The effect of NO-aspirin on pancreatic carcinogenesis was investigated by assessing the development of precursor pancreatic lesions and adenocarcinomas in Kras(G12D/+) transgenic mice that recapitulate human pancreatic cancer progression. Six-week-old male p48(Cre/+)-LSL-Kras(G12D/+) transgenic mice (20 per group) were fed diets containing 0, 1000, or 2000 ppm NO-aspirin. The development of pancreatic tumors was monitored by positron emission tomography imaging. All mice were killed at the age of 41 weeks and assessed for pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma (PDAC) and for molecular changes in the tumors. Our results reveal that NO-aspirin at 1000 and 2000 ppm significantly suppressed pancreatic tumor weights, PDAC incidence, and carcinoma in situ (PanIN-3 lesions). The degree of inhibition of PanIN-3 and carcinoma was more pronounced with NO-aspirin at 1000 ppm (58.8% and 48%, respectively) than with 2000 ppm (47% and 20%, respectively). NO-aspirin at 1000 ppm significantly inhibited the spread of carcinoma in the pancreas (∼97%; P < .0001). Decreased expression of cyclooxygenase (COX; with ∼42% inhibition of total COX activity), inducible nitric oxide synthase, proliferating cell nuclear antigen, Bcl-2, cyclin D1, and β-catenin was observed, with induction of p21, p38, and p53 in the pancreas of NO-aspirin-treated mice. These results suggest that low-dose NO-aspirin possesses inhibitory activity against pancreatic carcinogenesis by modulating multiple molecular targets.

Celecoxib and GABA cooperatively prevent the progression of pancreatic cancer in vitro and in xenograft models of stress-free and stress-exposed mice

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and is associated with high levels of psychological distress. We have shown that beta-adrenergic receptors (β-ARs), which are activated by stress neurotransmitters, regulate PDAC cells via cyclic AMP (cAMP)-dependent signaling in vitro, that social stress promotes PDAC progression in mouse xenografts and that γ-aminobutyric acid (GABA) inhibits these responses in vitro and in vivo. The targeted inhibition of stress-induced regulatory pathways may abolish the potentially negative impact of psychological stress on clinical outcomes. Our current data show that chronic exposure of PDAC cell lines Panc-1 (activating point mutations in K-ras) and BXPC-3 (no mutations in K-ras) in vitro to the stress neurotransmitter epinephrine at the concentration (15 nM) previously measured in the serum of mice exposed to social stress significantly increased proliferation and migration. These responses were inhibited in a concentration-dependent manner by celecoxib. The effects of celecoxib alone and in combination with γ-aminobutyric acid (GABA) on the progression of subcutaneous mouse xenografts from the cell line (BXPC-3) most responsive to epinephrine were then investigated in the presence and absence of social stress. Cancer-stimulating factors (VEGF & prostaglandin E(2) [PGE(2)]) and levels of cAMP were measured by immunoassays in blood and xenograft tissue. Phosphorylation of the signaling proteins ERK, CREB, Src, and AKT was assessed by ELISA assays and Western blotting. Expression of COX-2, 5-lipoxygenase, and p-5-LOX were determined by semi-quantitative Western blotting. Celecoxib alone significantly inhibited xenograft progression and decreased systemic and tumor VEGF, PGE2, and cAMP as well as phosphorylated signaling proteins in stress-exposed and stress-free mice. These responses were significantly enhanced by co-treatment with GABA. The celecoxib-induced downregulation of COX-2 protein and p-5-LOX was also significantly enhanced by GABA under both experimental conditions. Our findings identify the targeted inhibition of stress-induced pathways as a promising area for more effective cancer intervention in pancreatic cancer.

Non-steroidal anti-inflammatory drugs, acetaminophen, and risk of skin cancer in the Nurses' Health Study

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with lower risk of certain cancers, but data on the effect on skin cancer risk have been limited and contradictory. We prospectively examined whether use of NSAIDS or acetaminophen was associated with a lower risk of skin cancer in women.

METHODS

The 92,125 Caucasian women in the Nurses' Health Study provided information on aspirin use in 1980. Other NSAIDs and acetaminophen were added in 1990. Medication use, frequency, and quantity were reassessed on biennial questionnaires. Through 2008, we confirmed 658 melanoma cases, 1,337 squamous cell carcinoma (SCC) cases, and had 15,079 self-reports of basal cell carcinoma (BCC). We used COX proportional hazards models to compute relative risks (RR) adjusted for known skin cancer risk factors.

RESULTS

Neither aspirin nor non-aspirin NSAID use was associated with a lower risk of melanoma, SCC, or BCC, even for women with high quantity, frequency, or duration of use. Instead, we observed an increased risk of melanoma among current aspirin users (RR = 1.32, 95 % CI 1.03-1.70), though an increase of similar magnitude among past users and lack of a dose-response effect did not support a pharmacologic mechanism. We observed a mild reduction in SCC risk in current acetaminophen users (RR = 0.88, 95 % CI 0.75-1.02), with a linear decrease in risk with greater frequency of use (p = 0.04).

CONCLUSIONS

Aspirin and other NSAIDs were not associated with a lower risk of melanoma, SCC, or BCC in women. Our large, prospective study does not support a chemoprotective effect of NSAIDs against skin cancers.

High Expression of Complement Component 5 (C5) at Tumor Site Associates with Superior Survival in Ewing's Sarcoma Family of Tumour Patients

Background. Unlike in most adult-onset cancers, an association between typical paediatric neoplasms and inflammatory triggers is rare. We studied whether immune system-related genes are activated and have prognostic significance in Ewing's sarcoma family of tumors (ESFTs). Method. Data analysis was performed on gene expression profiles of 44 ESFT patients, 11 ESFT cell lines, and 18 normal skeletal muscle samples. Differential expression of 238 inflammation and 299 macrophage-related genes was analysed by t-test, and survival analysis was performed according to gene expression. Results. Inflammatory genes are activated in ESFT patient samples, as 38 of 238 (16%) inflammatory genes were upregulated (P < 0.001) when compared to cell lines. This inflammatory gene activation was characterized by significant enrichment of macrophage-related gene expression with 58 of 299 (19%) of genes upregulated (P < 0.001). High expression of complement component 5 (C5) correlated with better event-free (P = 0.01) and overall survival (P = 0.004) in a dose-dependent manner. C5 and its receptor C5aR1 expression was verified at protein level by immunohistochemistry on an independent ESFT tumour tissue microarray. Conclusion. Immune system-related gene activation is observed in ESFT patient samples, and prognostically significant inflammatory genes (C5, JAK1, and IL8) for ESFT were identified.

Aspirin, nonsteroidal anti-inflammatory drugs, acetaminophen, and pancreatic cancer risk: a clinic-based case-control study

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID) show indisputable promise as cancer chemoprevention agents. However, studies have been inconsistent as to whether aspirin has a protective effect in development of pancreatic cancer. To further evaluate the association between aspirin, NSAID, and acetaminophen use with pancreatic cancer risk, we used a clinic-based case-control study of 904 rapidly ascertained histologically or clinically documented pancreatic ductal adenocarcinoma cases, and 1,224 age- and sex-matched healthy controls evaluated at Mayo Clinic from April 2004 to September 2010. Overall, there is no relationship between non-aspirin NSAID or acetaminophen use and risk of pancreatic cancer. Aspirin use for 1 d/mo or greater was associated with a significantly decreased risk of pancreatic cancer (OR = 0.74, 95% CI: 0.60-0.91, P = 0.005) compared with never or less than 1 d/mo. Analysis by frequency and frequency-dosage of use categories showed reduced risk (P = 0.007 and 0.022, respectively). This inverse association was also found for those who took low-dose aspirin for heart disease prevention (OR = 0.67, 95% CI: 0.49-0.92, P = 0.013). In subgroup analyses, the association between aspirin use and pancreatic cancer was not significantly affected by pancreatic cancer stage, smoking status, or body mass index. Our data suggest that aspirin use, but not non-aspirin NSAID use, is associated with lowered risk of developing pancreatic cancer.

Experimental animal models of pancreatic carcinogenesis for prevention studies and their relevance to human disease

Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5' CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

Aspirin use and pancreatic cancer risk

Preclinical findings suggest that aspirin might inhibit pancreatic carcinogenesis, but epidemiological data are scanty and controversial. The role of aspirin use in pancreatic cancer is further analyzed in a multicentric hospital-based case-control study conducted in Italy between 1991 and 2008. Cases were 308 patients with incident pancreatic cancer and controls were 477 patients admitted to the same hospitals as cases for acute conditions, not related to risk factors for pancreatic cancer. A total of 22 cases (7%) and 37 controls (8%) reported regular aspirin use, with a corresponding adjusted odds ratio (OR) of 0.87 [95% confidence interval (CI): 0.47-1.61]. A slight protection, although not significant, was observed for duration of use > or =5 years (OR=0.53; 95% CI: 0.21-1.33) and for time since first use > or =10 years (OR=0.69; 95% CI: 0.25-1.93). The risk of pancreatic cancer was significantly below unity for current users of > or =5 years (OR=0.23; 95% CI: 0.06-0.90), but the risk was based on three cases and 16 controls only. We observed no association between regular aspirin use and pancreatic cancer risk, although our results suggested a possible protective effect for long-term current users.

Cyclooxygenase-deficient pancreatic cancer cells use exogenous sources of prostaglandins

Genes that are differentially expressed in pancreatic cancers and under epigenetic regulation are of considerable biological and therapeutic interest. We used global gene expression profiling and epigenetic treatment of pancreatic cell lines including pancreatic cancer cell lines, pancreatic cancer-associated fibroblasts, and cell lines derived from nonneoplastic pancreata. We examined expression and epigenetic alterations of cyclooxygenase-1 (COX-1) and COX-2 in pancreatic cancers and normal pancreas and performed proliferation, knockdown, and coculture experiments to understand the role of stromal sources of prostaglandins for pancreatic cancers. We identify COX-1 as a gene under epigenetic regulation in pancreatic cancers. We find that COX-1 expression is absent in many pancreatic cancer cells and some of these cancers also lack COX-2 expression. Suspecting that such cancers must rely on exogenous sources of prostaglandins, we show that pancreatic cancer stromal cells, such as fibroblasts expressing COX-1 and COX-2, are a likely source of prostaglandins for pancreatic cancer cells deficient in COX. Knocking down the prostaglandin transporter multidrug resistance-associated protein-4 in fibroblasts suppresses the proliferation of cocultured pancreatic cancer cells lacking COX. Pancreatic cancers that lack COX can use exogenous sources of prostaglandins. Blocking multidrug resistance-associated protein-4 may be a useful therapeutic strategy to deplete COX-deficient pancreatic cancers of prostaglandins.

Chemoprevention strategies for pancreatic cancer

Pancreatic cancer has a poor prognosis and is often diagnosed at an advanced stage, which makes it difficult to treat. The low survival rate of patients with pancreatic cancer points towards an increased need for novel therapeutic and chemopreventive strategies and also early detection of this disease. Increased consumption of fruits and vegetables has been associated with a reduced risk of pancreatic cancer. Synthetic and natural, diet-derived bioactive compounds have been evaluated as pancreatic cancer chemopreventive agents and have demonstrated various degrees of efficacy in cellular and in vivo animal models. Some chemopreventive agents (for example, curcumin or resveratrol) have also been reported to sensitize pancreatic cancer cells to standard chemotherapeutic drugs (for example, gemcitabine or erlotinib), which suggests that chemopreventive agents could potentially be used as potentiators of standard chemotherapy. Few clinical trials of pancreatic cancer chemopreventive agents have been completed and some are in early phases. Further development of pancreatic cancer chemopreventive agents may prove to be tremendously valuable for individuals at high risk of developing pancreatic cancer and patients who present with premalignant lesions. This Review discusses the current state of the pancreatic cancer chemoprevention field and highlights the challenges ahead.

Non-steroidal anti-inflammatory drugs and pancreatic cancer risk: a nested case-control study

Background:

Non-steroidal anti-inflammatory drug (NSAID) use has been linked with pancreatic cancer risk; however, findings from epidemiological studies are inconsistent.

Methods:

A nested case–control study was conducted within the UK General Practice Research Database. Cases (n=1141) had a diagnosis of primary cancer of the exocrine pancreas between January 1995 and June 2006. Controls (n=7954) were matched with each case on general practice site, sex and year of birth. Conditional logistic regression analyses were used to generate odds ratios (OR) and 95% confidence intervals (CI) associated with NSAID use compared with non-use.

Results:

Any use of NSAID in the 5 years before the index date or since entry into the database (excluding the year before diagnosis) was not associated with risk of pancreatic cancer; OR 0.96 (95% CI, 0.84–1.10) and 1.03 (95% CI 0.89–1.19), respectively. Exposure to NSAIDs for > 773 days, in the 5 years pre-diagnosis, was associated with a reduced risk of pancreatic cancer OR 0.78 (95%CI 0.62–0.97). There was evidence of reduced pancreatic cancer risk with long-term use (5 years or more) of lower doses of NSAIDs OR 0.70 (95% CI 0.49–0.99).

Conclusion:

Long-term exposure to NSAIDs may be associated with a reduction in risk of pancreatic cancer.

IKK- and NF-κB-mediated functions in carcinogenesis

Since the initial cloning of RelA and its close relationship to c-Rel, the cellular homolog of the viral oncoprotein v-Rel, the nuclear factor κB (NF-κB) signaling pathway and its upstream activating kinase complex (IκB-kinase) have been suspected to play a major role in tumorigenesis. This was further corroborated by the discovery of oncogenic mutations in NF-κB proteins in certain lymphoid malignancies and the notion that NF-κB is persistently activated in a large variety of solid tumors. With the advent of conditional knockout mice allowing tissue-specific targeting of the various components of the NF-κB signaling pathway, it was possible to genetically test the cell autonomous and non-autonomous functions of NF-κB in inflammation-associated cancer as well as sporadic cancers. Here, we review molecular evidence that demonstrates the various functions of NF-κB during different tumor stages and that supports the rationale to target NF-κB in cancer prevention and therapy.

Epidemiology of pancreatic cancer: an overview

Pancreatic cancer, although infrequent, has an exceptionally high mortality rate, making it one of the four or five most common causes of cancer mortality in developed countries. The incidence of pancreatic cancer varies greatly across regions, which suggests roles for lifestyle factors, such as diet, or environmental factors, such as vitamin D exposure. Smoking is the most common known risk factor, and is the cause of 20-25% of all pancreatic tumors. Alcohol does not seem to be a risk factor, unless it leads to chronic pancreatitis, which is a probable risk factor. Long-standing diabetes increases the risk of pancreatic cancer, but can also be an early manifestation of pancreatic tumors. 5-10% of patients with pancreatic cancer have an underlying germline disorder, while the remaining percentage of cancer cases is thought to be caused by somatic mutations. Some individual studies suggest that mutations in various polymorphic genes can lead to small increases in the risk of pancreatic cancer, but these findings need to be replicated. Rising prevalence of smoking in developing countries, improved diagnosis and increasing population longevity are all likely to increase the global burden of pancreatic cancer in the coming decades.

Medical management of pancreatic adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer death in the United States. In 2008, an estimated 34,290 people died from pancreatic cancer and 37,680 new cases were diagnosed. Despite modern treatment, 90% of patients die within 1 year of diagnosis. Pancreatectomy is still the only potentially curative approach, but most patients have incurable disease by the time they are diagnosed, and fewer than 20% are candidates for surgery. In the present paper the English-language literature addressing the medical management in pancreatic cancer was reviewed. Based on these data we will discuss the role of currently used chemotherapy and target therapy in pancreatic cancer, as well as perspectives of the emerging strategies that are arising in order to improve the outcomes of this complex disease.

Aspirin and cancer risk: a summary review to 2007

Aspirin has been associated with a reduced risk of colorectal cancer and--based on limited evidence--to cancers of the oesophagus, stomach, breast, ovary and lung. The role of aspirin on other cancers, such as pancreatic, prostate and bladder cancer and non-Hodgkin's lymphomas and myeloma is less clear, and an increase of risk has been suggested for kidney cancer. For most cancer sites, however, significant heterogeneity between studies, and particularly between study design, was found, with a reduction in risk generally stronger in case-control studies than in cohort ones.

Damage to cellular and isolated DNA induced by a metabolite of aspirin

Aspirin has been proposed as a possible chemopreventive agent. On the other hand, a recent cohort study showed that aspirin may increase the risk for pancreatic cancer. To clarify whether aspirin is potentially carcinogenic, we investigated the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), which is correlated with the incidence of cancer, in cultured cells treated with 2,3-dihydroxybenzoic acid (2,3-DHBA), a metabolite of aspirin. 2,3-DHBA induced 8-oxodG formation in the PANC-1 human pancreatic cancer cell line. 2,3-DHBA-induced DNA single-strand breaks were also revealed by comet assay using PANC-1 cells. Flow cytometric analyses showed that 2,3-DHBA increased the levels of intracellular reactive oxygen species (ROS) in PANC-1 cells. The 8-oxodG formation and ROS generation were also observed in the HL-60 leukemia cell line, but not in the hydrogen peroxide (H(2)O(2))-resistant clone HP100 cells, suggesting the involvement of H(2)O(2). In addition, an hprt mutation assay supported the mutagenicity of 2,3-DHBA. We investigated the mechanism underlying the 2,3-DHBA-induced DNA damage using (32)P-labeled DNA fragments of human tumor suppressor genes. 2,3-DHBA induced DNA damage in the presence of Cu(II) and NADH. DNA damage induced by 2,3-DHBA was enhanced by the addition of histone peptide-6 [AKRHRK]. Interestingly, 2,3-DHBA and histone peptide-6 caused base damage in the 5'-ACG-3' and 5'-CCG-3' sequences, hotspots of the p53 gene. Bathocuproine, a Cu(I) chelator, and catalase inhibited the DNA damage. Typical hydroxyl radical scavengers did not inhibit the DNA damage. These results suggest that ROS derived from the reaction of H(2)O(2) with Cu(I) participate in the DNA damage. In conclusion, 2,3-DHBA induces oxidative DNA damage and mutations, which may result in carcinogenesis.

Effect of celecoxib and the novel anti-cancer agent, dimethylamino-parthenolide, in a developmental model of pancreatic cancer

OBJECTIVES

Cancer of the exocrine pancreas is the fourth leading cause of cancer-related deaths in the United States. The efficacy of a novel bioavailable anticancer agent, dimethylamino-parthenolide (DMAPT), and the cyclooxygenase 2 inhibitor, celecoxib, was evaluated in a carcinogen-induced developmental model of pancreatic cancer.

METHODS

Syrian golden hamsters were injected with N-nitrosobis(2-oxopropyl)amine, once weekly for 6 weeks. Upon the first injection, hamsters were randomized as follows: placebo, low-/high-dose DMAPT (20 and 40 mg/kg per day), low-/high-dose celecoxib (10and 50 mg/kg per day), or combination DMAPT/celecoxib (low/low, high/high).

RESULTS

The 32-week trial showed that 40 mg/kg DMAPT alone significantly decreased the size of gross pancreatic cancers relative to placebo. No significant difference in gross tumor number was observed between the treatment groups and placebo with the exception of 50 mg/kg celecoxib with a higher tumor incidence; this group also exhibited lower lymphotactin levels suggestive of decreased immune surveillance. Tumor invasion into adjacent organs and metastasis were not observed in the DMAPT/celecoxib treatment groups. Drug targets including prostaglandin E2, prostaglandin E2 metabolite and activated nuclear factor kappaB were significantly decreased.

CONCLUSIONS

Dimethylamino-parthenolide and celecoxib have the potential to be novel chemotherapeutic agents for pancreatic cancer; however, further optimization or the use of other modalities may be required for chemoprevention.

Aspirin, NSAID, and acetaminophen use and the risk of endometrial cancer

To date, no prospective studies have explored the relationship between the use of aspirin, other nonsteroidal anti-inflammatory medications (NSAID), and acetaminophen and endometrial adenocarcinoma. Of the 82,971 women enrolled in a prospective cohort study, 747 developed medical record-confirmed invasive endometrial cancer over a 24-year period. Use of aspirin was ascertained from 1980 to 2004, and for other NSAIDs and acetaminophen, from 1990 to 2004. Cox regression models calculated multivariate relative risks (MV RR), controlling for body mass index (BMI), postmenopausal hormone (PMH) use, and other endometrial cancer risk factors. Currency, duration, and quantity of aspirin were not associated with endometrial cancer risk overall [current use: MV RR, 1.03; 95% confidence interval (CI) 0.83-1.27; >10 years of use: MV RR, 1.01; 95% CI, 0.78-1.30; and cumulative average >7 tablets per week: (MV RR, 1.10; 95% CI, 0.84-1.44)]. However, stratified analyses showed that a lower risk of endometrial cancer among obese (BMI, >or=30 kg/m(2)) women was seen with current aspirin use (MV RR, 0.66; 95% CI, 0.46-0.95). The greatest risk reduction for current aspirin users was seen in postmenopausal obese women who had never used PMH (MV RR, 0.43; 95% CI, 0.26-0.73). The use of other NSAIDs or acetaminophen was not associated with endometrial cancer. Our data suggest that use of aspirin or other NSAIDs does not play an important role in endometrial cancer risk overall. However, risk was significantly lower for current aspirin users who were obese or who were postmenopausal and had never used PMHs; these subgroup findings require further confirmation.

NCX 4040, an NO-donating acetylsalicylic acid derivative: efficacy and mechanisms of action in cancer cells

Non-steroidal anti-inflammatory drugs (NSAIDs) have repeatedly shown to be effective in tumor prevention, but important side-effects limit their wide clinical use. Nitric oxide-releasing derivatives (NO-NSAIDs) are a promising class of compounds synthesized by combining a classic NSAID molecule with an NO-releasing moiety to counteract side-effects. These new chemical entities exhibit a significantly higher activity and much lower toxicity with respect to the parental drug. In the present paper, we report the results obtained from in in vitro experimental systems aimed to evaluate the activity and mechanisms of action of the novel NO-releasing aspirin derivative, NCX 4040. The in vitro studies were carried out on a panel of human colon (LoVo, LoVo Dx, WiDr, LRWZ), bladder (HT1376, MCR), and pancreatic (Capan-2, MIA PaCa-2, T3M4) cancer cell lines. With regard to colon cancer, NCX 4040 activity was also investigated in vitro in combination with drugs currently used in clinical practice and was validated in vivo on tumor-bearing mice xenografted with the aforementioned colon cancer cell lines. The in vitro studies showed a high cytotoxic activity of NCX 4040 in all tumor histotypes and demonstrated the pivotal role of the NO component in drug activity. It was also observed that NCX 4040 exerts a pro-apoptotic activity via a mitochondria-dependent pathway. Moreover, the in vivo studies on xenografted mice further confirmed the antitumor efficacy and low toxicity of NCX 4040 in colon cancer and highlighted its role as sensitizing agent of oxaliplatin cytotoxicity.

Pancreatic cancer: a review of the evidence on causation

Pancreatic cancer kills more than 250,000 people each year worldwide and has a poor prognosis. The aim of this article is to critically review the epidemiologic evidence for exposures that may either increase or decrease the risk. A Medline search was performed for epidemiologic studies and reviews published up to April 2007. Consistent evidence of a positive association was found for family history and cigarette smoking. Many studies documented a positive association with diabetes mellitus and chronic pancreatitis, although the etiologic mechanisms are unclear. Other associations were detected, but the results were either inconsistent or from few studies. These included positive associations with red meat, sugar, fat, body mass index, gallstones, and Helicobacter pylori, and protective effects of increasing parity, dietary folate, aspirin, and statins. There was no evidence linking alcohol or coffee consumption with an increased risk of pancreatic cancer. The associations with many exposures need to be clarified from further epidemiologic work in which there is both precise measurement of risk factors, adjustment for potential confounders, and, for dietary studies, information recorded on the method of food preparation and pattern of consumption. Such work is important to reduce the incidence of this fatal disease.