Allergies and the risk of pancreatic cancer: a meta-analysis with review of epidemiology and biological mechanisms

Epidemiology: allergy history, IgE, and cancer

Numerous epidemiological studies have investigated potential associations between allergy history and cancer risk with strong inverse associations reported in studies of pancreatic cancer, glioma, and childhood leukemia. Recently, there has been a rapid expansion of the epidemiological literature both of studies evaluating self-reported allergy history in relation to cancer risk and of studies evaluating biological indicators of allergy history and immune function including levels of immunoglobulin (Ig) E. However, there are several potential methodological limitations associated with prior studies, and further research is required to clarify associations observed. This paper summarizes the recent epidemiological literature examining associations between allergy history and cancer risk. From 2008, a total of 55 epidemiological studies were identified that examined some aspect of the association between allergy and cancer. Although the majority of studies examined self-reported allergy history in relation to cancer risk, there were also studies examining allergy diagnoses or discharges as captured in existing administrative databases, levels of IgE, polymorphisms of allergy, inflammatory- or allergy-related cytokine genes, and concentrations of immune regulatory proteins. The most frequently studied cancer sites included brain and lymphatic and hematopoietic cancers. Potential methodological sources of bias are discussed as well as recommendations for future work.

Allergies and risk of head and neck cancer

BACKGROUND

Individuals with allergies have a heightened Th2 (T helper 2) immunity, which may provide advantages in controlling tumor growth. Inverse associations have been reported among individuals with allergies and risk of brain and pancreatic cancers.

METHODS

We examined the relationship between allergies and risk of head and neck squamous cell carcinoma (HNSCC) in a population-based case-control study with 1,014 cases and 1,193 frequency-matched controls. Logistic regression models were used to estimate odds ratios (OR) and 95 % confidence intervals (95 % CI) controlling for age, sex, race, smoking history, alcohol consumption, and education. In addition, in a subset of the population, models were adjusted for HPV16 status.

RESULTS

Individuals with allergies had a 19 % lower risk of HNSCC (OR = 0.81, 95 % CI = 0.67-0.98). Associations with allergies were stronger for laryngeal (OR = 0.66, 95 % CI = 0.45-0.97) and oropharyngeal (OR = 0.73, 95 % CI = 0.57-0.92) cancers, while no association was observed for oral cavity cancers (OR = 0.98, 95 % CI = 0.76-1.26). History of asthma was not associated with overall HNSCC, but the association was statistically significant for oropharyngeal cancer (OR = 0.67, 95 % CI = 0.44-0.99). HPV16 status did not confound or modify the associations with allergies.

CONCLUSIONS

Elevated Th2 immunity in individuals with history of allergies and asthma may reduce the risk of HNSCC. Additional research into related mechanisms may provide new insights into how to treat HNSCC.

IMPACT

These findings may provide new insight into biological pathways that could lead to a better understanding of the etiology of this disease.

A replication study and genome-wide scan of single-nucleotide polymorphisms associated with pancreatic cancer risk and overall survival

PURPOSE

To explore the effects of single-nucleotide polymorphisms (SNP) on pancreatic cancer risk and overall survival (OS).

EXPERIMENTAL DESIGN

The germ line DNA of 531 pancreatic cancer cases and 305 healthy controls from a hospital-based study was genotyped at SNPs previously reported to be associated with pancreatic cancer risk or clinical outcome. We analyzed putative risk SNPs for replication of their reported effects on risk and tested for novel effects on OS. Similarly, we analyzed putative survival-associated SNPs for replication of their reported effects on OS and tested for novel effects on risk. Finally, we conducted a genome-wide association study (GWAS) of OS using a subset of 252 cases, with two subsequent validation sets of 261 and 572 patients, respectively.

RESULTS

Among seven risk SNPs analyzed, two (rs505922 and rs9543325) were associated with risk (P < 0.05). Among 24 survival-associated SNPs analyzed, one (rs9350) was associated with OS (P < 0.05). No putative risk SNPs or putative survival-associated SNPs were found to be associated with OS or risk, respectively. Furthermore, our GWAS identified a novel SNP [rs1482426, combined stage I and II, P = 1.7 × 10(-6), per-allele HR, 1.74; 95% confidence interval (CI), 1.38-2.18] to be putatively associated with OS.

CONCLUSIONS

The effects of SNPs on pancreatic cancer risk and OS were replicated in our study, although further work is necessary to understand the functional mechanisms underlying these effects. More importantly, the putative association with OS identified by GWAS suggests that GWAS may be useful in identifying SNPs associated with clinical outcome in pancreatic cancer.

Epidemiology of pancreatic cancer and the role of family history

Pancreatic cancer is a lethal disease for which only a small number of risk factors have been identified. In addition to older age, male gender, and black race, risk factors include smoking, obesity, long-standing diabetes and pancreatitis, and heavy alcohol use; allergies such as hay fever are related to lowered risk. Several genetic syndromes increase risk of pancreatic cancer. Work on more common genetic variants promises to reveal more potentially important genetic associations.

Selected medical conditions and risk of pancreatic cancer

We review the current evidence for associations of several medical conditions with risk of pancreatic cancer, including allergies, pancreatitis, gall bladder disease, cholecystectomy, ulcers, gastrectomy, appendectomy, and tonsillectomy. There are consistent findings of reduced risk associated with presence of self-reported allergies, particularly hay fever but not asthma; data on other allergies are limited and inconclusive. Several studies provide evidence that patients with pancreatic cancer are more likely than comparison groups to report pancreatitis. Those studies that investigated the time between onset of pancreatitis and diagnosis of pancreatic cancer found that risk estimates declined with longer periods of time; however, increased risks were noted for long-term pancreatitis, indicating that this condition is both a risk factor and a sign of early disease. Increased risk was reported in association with cholelithiasis, but the few studies that considered time before diagnosis of cancer did not find increased risk for cholelithiasis diagnosed in the more distant past. There is weak evidence that cholecystectomy 2 or more years before cancer diagnosis is related to risk, but this is based on only a few studies. There is no consistent association between ulcers and risk, while gastrectomy may increase risk. Overall, study of these conditions, particularly those that are rare, presents methodologic challenges. Time between diagnoses is likely to be important but is not considered in most studies. Lack of adequate control in several studies for risk factors such as smoking and heavy alcohol use also makes it difficult to draw firm conclusions about these results.

Epidemiology and potential mechanisms of tobacco smoking and heavy alcohol consumption in pancreatic cancer

Tobacco smoking represents an important known cause of ductal pancreatic adenocarcinoma. Recent data from pooled analyses in consortia involving multiple case-control and cohort studies suggest that heavy (but not moderate or light) alcohol consumption also may increase pancreatic cancer risk. Animal and human evidence indicate that tobacco carcinogens and metabolites may act in concert and have both genetic and epigenetic effects at early and later stages in pancreatic tumorigenesis. One of the more important tobacco-related carcinogens, NNK, probably acts via multiple pathways. Heavy alcohol consumption may increase pancreatic cancer risk by potentiating the effects of other risk factors such as tobacco smoking, poor nutrition, and inflammatory pathways related to chronic pancreatitis, but also may have independent genetic and epigenetic effects. Animal and human studies of tobacco- and alcohol-related pancreatic carcinogenesis suggest multi-modal, overlapping mechanistic pathways. Tobacco smoking and heavy alcohol consumption are preventable exposures, and their avoidance would substantially decrease the burden of pancreatic cancer worldwide.

Associations of high-grade glioma with glioma risk alleles and histories of allergy and smoking

Glioma risk has consistently been inversely associated with allergy history but not with smoking history despite putative biologic plausibility. Data from 855 high-grade glioma cases and 1,160 controls from 4 geographic regions of the United States during 1997-2008 were analyzed for interactions between allergy and smoking histories and inherited variants in 5 established glioma risk regions: 5p15.3 (TERT), 8q24.21 (CCDC26/MLZE), 9p21.3 (CDKN2B), 11q23.3 (PHLDB1/DDX6), and 20q13.3 (RTEL1). The inverse relation between allergy and glioma was stronger among those who did not (odds ratio(allergy-glioma) = 0.40, 95% confidence interval: 0.28, 0.58) versus those who did (odds ratio(allergy-glioma) = 0.76, 95% confidence interval: 0.59, 0.97; P(interaction) = 0.02) carry the 9p21.3 risk allele. However, the inverse association with allergy was stronger among those who carried (odds ratio(allergy-glioma) = 0.44, 95% confidence interval: 0.29, 0.68) versus those who did not carry (odds ratio(allergy-glioma) = 0.68, 95% confidence interval: 0.54, 0.86) the 20q13.3 glioma risk allele, but this interaction was not statistically significant (P = 0.14). No relation was observed between glioma risk and smoking (odds ratio = 0.92, 95% confidence interval: 0.77, 1.10; P = 0.37), and there were no interactions for glioma risk of smoking history with any of the risk alleles. The authors' observations are consistent with a recent report that the inherited glioma risk variants in chromosome regions 9p21.3 and 20q13.3 may modify the inverse association of allergy and glioma.

Diabetes mellitus, other medical conditions and pancreatic cancer: a case-control study

BACKGROUND

Diabetes and other medical conditions have been related to pancreatic cancer, but time risk quantification is unsettled.

METHODS

We combined data from two case-control studies conducted in Italy, including 688 pancreatic cancer cases and 2204 controls. All subjects were interviewed by trained interviewers during their hospital stay. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using multiple logistic regression.

RESULTS

Overall, 103 cases (15%) and 125 controls (5.7%) reported a history of diabetes. The OR for pancreatic cancer was more pronounced among those diagnosed with diabetes in the previous 2 years (OR = 5.17; 95% CI = 2.71-9.87) than among those with diabetes diagnosed more than 2 years ago (OR = 2.35; 95% CI = 1.70-3.26). The ORs remained significantly elevated 2-4 years (OR = 3.81; 95% CI = 2.07-7.04) and 5-9 years (OR = 3.75; 95% CI = 2.13-6.59) since diagnosis of diabetes, after which a non-significant 20% increased risk for pancreatic cancer was observed. As compared to non-diabetic non-smokers, the OR was 1.85 among non-diabetic current smokers, 2.17 among diabetic never/former smokers, and rose to 4.67 among diabetic current smokers, indicating a multiplicative effect between these two risk factors. Pancreatic cancer was significantly associated with pancreatitis, primarily among those diagnosed within 2 years (OR = 7.16; 95% CI = 2.25-22.78). In addition, the ORs were elevated for cholelithiasis (3.53; 95% CI = 1.67-7.45) and gastroduodenal ulcer (3.16; 95% CI = 1.14-8.73) only among those diagnosed within the past 2 years.

CONCLUSIONS

Diabetes is associated with heightened risk of pancreatic cancer. The association is significant for diabetes diagnosed up to 10 years before pancreatic cancer.

Histamine deficiency promotes inflammation-associated carcinogenesis through reduced myeloid maturation and accumulation of CD11b+Ly6G+ immature myeloid cells

Histidine decarboxylase (HDC), the unique enzyme responsible for histamine generation, is highly expressed in myeloid cells but its function is poorly understood. Here, we show that Hdc knockout mice exhibit a markedly increased rate of colon and skin carcinogenesis. Using Hdc-EGFP BAC transgenic mice, we demonstrate that Hdc is expressed primarily in CD11b⁺Ly6G⁺ immature myeloid cells (IMCs) that are recruited early on in chemical carcinogenesis. Transplant of Hdc-deficient bone marrow to wildtype recipients results in increased CD11b⁺Ly6G⁺ cell mobilization and reproduces the cancer susceptibility phenotype. In addition, IMCs from Hdc knockout mice promote the growth of cancer xenografts and colon cancer cells downregulate Hdc expression through promoter hypermethylation and inhibits myeloid cell maturation. Exogenous histamine induces the differentiation of IMCs and suppresses their ability to support the growth of xenografts. These data indicate key roles for Hdc and histamine in myeloid cell differentiation, and CD11b⁺Ly6G⁺ IMCs in early cancer development.

[The epidemiology of pancreatic cancer]

Pancreatic cancer is a relatively uncommon tumor, but even with early diagnosis, mortality rates are high, explaining why this form of cancer has now become a common cause of cancer mortality. There are no screening tests for early detection of pancreatic cancer. It is more common in men than women and is predominantly a disease of elderly people. There is wide variation in the incidence of pancreatic cancer around the world, suggesting that environmental factors are important in the pathogenesis. Smoking is the major known risk factor for pancreatic cancer, while dietary factors seem to be less important. Other possible risk factors include chronic pancreatitis, obesity and type 2 diabetes. Numerous inherited germ line mutations are associated with pancreatic cancer. Of these, hereditary pancreatitis confers the greatest risk, while BRCA2 mutations are the commonest inherited disorder. Polymorphisms in genes that control detoxification of environmental carcinogens and metabolic pathways may alter the risk of pancreatic cancer.

Allergies, obesity, other risk factors and survival from pancreatic cancer

Survival from pancreatic adenocarcinoma remains extremely poor, approximately 5% at 5 years. Risk factors include smoking, high body mass index (BMI), family history of pancreatic cancer, and long-standing diabetes; in contrast, allergies are associated with reduced risk. Little is known about associations between these factors and survival. We analyzed overall survival in relation to risk factors for 475 incident cases who took part in a hospital based case-control study. Analyses were conducted separately for those who did (160) and did not (315) undergo tumor resection. Kaplan-Meier methods were used to describe survival according to smoking, BMI, family history, diabetes, and presence of allergies. Cox proportional hazards models were used to adjust for covariates. There was no association with survival based on smoking, family history, or history of diabetes in either group. Among patients with resection, those with allergies showed nonstatistically significant longer survival, a median of 33.1 months (95% CI: 19.0-52.5) vs. 21.8 months (95% CI: 18.0-33.1), p = 0.25. The adjusted hazard ratio (HR) was 0.72 (95% CI: 0.43-1.23), p = 0.23. Among patients without resection, those with self-reported allergies survived significantly longer than those without allergies: 13.3 months (95% CI: 10.6-16.9) compared to 10.4 months (95% CI: 8.8-11.0), p = 0.04, with an adjusted HR of 0.68 (95% CI: 0.49-0.95), p = 0.02. Obesity was nonsignificantly associated with poorer survival, particularly in the resected group (HR = 1.62, 95% CI: 0.76-3.44). The mechanisms underlying the association between history of allergies and improved survival are unknown. These novel results need to be confirmed in other studies.

Asthma, Asthma Medications, and Prostate Cancer Risk

Background: The aim of this study was to assess whether a history of asthma or the use of asthma medications is associated with prostate cancer risk.

Methods: Of 16,934 men participating in the Melbourne Collaborative Cohort Study, 1,179 were diagnosed with prostate cancer during an average follow-up of 13.4 years to the end of December 2007. Information on asthma history was obtained at baseline interview. Participants were asked to bring their current medications to the study center. The names of the drugs were entered into a form and coded. Asthma medications were categorized into four groups and corresponding hazard ratios (HR) were estimated from Cox regression models adjusted for country of birth.

Results: Asthma was associated with a small increase in prostate cancer risk [HR 1.25; 95% confidence interval (95% CI), 1.05-1.49]. The HRs for use of medications were 1.39 (95% CI, 1.03-1.88) for inhaled glucocorticoids, 1.71 (95% CI, 1.08-2.69) for systemic glucocorticoids, 1.36 (95% CI, 1.05-1.76) for bronchodilators, and 0.78 (95% CI, 0.45-1.35) for antihistamines. The HRs for asthma and asthma medication use changed only slightly after mutual adjustment.

Conclusions: A history of asthma and the use of asthma medications, particularly systemic glucocorticoids, are associated with an increased risk of prostate cancer, although it is difficult to disentangle the effects of asthma medications from those of asthma per se.

Impact: These findings, if confirmed in independent studies, might lead to the identification of new risk factors for prostate cancer. Cancer Epidemiol Biomarkers Prev; 19(9); 2318–24. ©2010 AACR.

Familial pancreatic cancer in Italy. Risk assessment, screening programs and clinical approach: a position paper from the Italian Registry

In Italy, pancreatic cancer is the fifth leading cause of tumor related death with about 7000 new cases per year and a mortality rate of 95%. In a recent prospective epidemiological study on the Italian population, a family history was found in about 10% of patients suffering from a ductal adenocarcinoma of the pancreas (PDAC). A position paper from the Italian Registry for Familial Pancreatic Cancer was made to manage these high-risk individuals. Even though in the majority of high-risk individuals a genetic test to identify familial predisposition is not available, a screening protocol seems to be reasonable for subjects who have a >10-fold greater risk for the development of PDAC. However this kind of screening should be included in clinical trials, performed in centers with high expertise in pancreatic disease, using the least aggressive diagnostic modalities.

History of asthma or eczema and cancer risk among men: a population-based case-control study in Montreal, Quebec, Canada

BACKGROUND

Epidemiologic evidence regarding the association between a history of allergic diseases and different cancer types has been inconsistent.

OBJECTIVE

To examine whether a history of asthma or eczema is associated with various cancers among Canadian men in a population based case-control study conducted in the 1980s.

METHODS

Questionnaire-based interviews were performed by a team of trained interviewers from August 1979 to March 1986. Information collected included self-reported history of a prior medical diagnosis of asthma and of eczema, medication use, and several covariates among 3,300 cancer cases and 512 population controls. Logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between asthma or eczema and more than 20 cancer types combined, as well as for each of the 8 most common cancer types (stomach, colon, rectum, lung, prostate, bladder, skin, and lymph nodes).

RESULTS

Considering study participants who reported a prior medical diagnosis of the disease and medication use, a history of asthma was negatively associated with all cancer types combined (OR, 0.72; 95% CI, 0.5-1.1) and similarly for a history of eczema (OR, 0.66; 95% CI, 0.4-1.1). Although ORs between asthma and eczema and most individual types were below 1.0, only 2 ORs were significantly below 1.0: that between asthma and stomach cancer (OR, 0.27; 95% CI, 0.1-0.9) and that between eczema and lung cancer (OR, 0.34; 95% CI, 0.2-0.7).

CONCLUSION

Allergic conditions that result from a hyperreactive immune system might lead to a more efficient elimination of abnormal cells, thus lowering cancer risks.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Risk factors and early diagnosis of pancreatic cancer]

Pancreatic cancer (PC) is usually incurable. Identifying people at risk for developing PC may improve the prognosis of this entity. The main risk factors for PC are Peutz-Jeghers syndrome, hereditary pancreatitis and a history family of PC. Other factors, such as advanced age and smoking, should also be taken into account. PC screening is only useful in very high risk individuals. Tools that allow tumors to be identified in the early stages are required in order to apply appropriate curative treatments. In this scenario, only endoscopic ultrasound with cytological analysis of suspicious pancreatic lesions has proved to be useful.

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.

Antitumor IgE adjuvanticity: key role of Fc epsilon RI

Working with C57BL/6 mouse tumor models, we had previously demonstrated that vaccination with IgE-coated tumor cells can protect against tumor challenge, an observation that supports the involvement of IgE in antitumor immunity. The adjuvant effect of IgE was shown to result from eosinophil-dependent priming of the T cell-mediated adaptive immune response. The protective effect is likely to be mediated by the interaction of tumor cell-bound IgE with receptors, which then trigger the release of mediators, recruitment of effector cells, cell killing and tumor Ag cross-priming. It was therefore of utmost importance to demonstrate the strict dependence of the protective effect on IgE receptor activation. First, the protective effect of IgE was confirmed in a BALB/c tumor model, in which IgE-loaded modified VV Ankara-infected tumor cells proved to be an effective cellular vaccine. However, the protective effect was lost in Fc(epsilon)RIalpha(-/-) (but not in CD23(-/-)) knockout mice, showing the IgE-Fc(epsilo)nRI interaction to be essential. Moreover, human IgE (not effective in BALB/c mice) had a protective effect in the humanized knockin mouse (Fc(epsilon)RIalpha(-/-) hFc(epsilon)RIalpha(+)). This finding suggests that the adjuvant effect of IgE could be exploited for human therapeutics.

Pancreatic adenocarcinoma in a young patient population--12-year experience at Memorial Sloan Kettering Cancer Center

BACKGROUND

There is a dearth of data in a younger population of patients with pancreatic ductal adenocarcinoma (PAC) regarding epidemiology, genetics, prognosis, and outcome. This report examines a large cohort of patients with PAC <or=45 years of age evaluated at MSKCC over a 12-year period.

METHODS

A retrospective analysis of patients referred to MSKCC with PAC identified from the institutional tumor registry, who were <or=45 years on the date of the diagnostic biopsy, between January 1995 and February 2008, was performed. Information reviewed included demographics, clinical and pathological staging, surgical management, therapy, date of relapse, death or last follow-up. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

One hundred thirty-six cases of PAC, age <or=45 years at diagnosis, were identified. Seventy-four (54%) females, 62 (46%) males. Age range: 24-45; 4, 38, and 94 patients in age groups 20-29, 30-39, 40-45 years, respectively. Fifty (37%) had a smoking history. Fourteen (10.3%) had a positive family history of PAC. Thirty-five (25.7%) underwent a curative resection for localized disease. Twenty-eight (20.1%) presented with locally advanced, inoperable disease. Sixty-eight (50%) presented as AJCC Stage IV. Twenty-three (37%) of those resected underwent adjuvant chemoradiation. Thirteen received adjuvant gemcitabine. The median overall survival for the entire cohort was 12.3 months (95% CI 10.2-14.0 months). The median overall survival for the patients with locally resectable disease was 41.8 months (95% CI 20.3-47 months). The median overall survival for the patients who presented with locally advanced, unresectable disease was 15.3 months (95% CI 12-19.3 months). The median overall survival for those who presented with metastatic disease was 7.2 months (95% CI 5.2-9.5 months).

CONCLUSIONS

This is the largest reported cohort of young patients with PAC <or=45 years of age. The data suggest that patients with stages I-II disease may have an improved prognosis, however the prognosis for stages III-IV patients appears to be similar to the typical (older) patient population with PAC.

Immunoglobulin E antibodies from pancreatic cancer patients mediate antibody-dependent cell-mediated cytotoxicity against pancreatic cancer cells

In addition to allergy and parasitic infections, immunoglobulin E (IgE) has been shown recently to possess anti-viral and anti-cancer effects. We investigated serum levels of IgE, its low-affinity receptor, soluble CD23 (sCD23) in patients with pancreatic cancer and the effect of IgE against pancreatic cancer cells. Twelve patients were evaluated for pancreatic cancer by imaging and confirmed by biopsy. Fifteen healthy volunteers served as controls. Serum Igs (IgG, IgM, IgA, IgE) and sCD23 levels were determined (enzyme-linked immunosorbent assay, nephelometry) and the presence of cancer-specific IgE was assessed (fluorescence microscopy, Western blot). IgE anti-cancer activity was determined by antibody-dependent cell-mediated cytotoxicity (ADCC). Serum levels of IgE and sCD23 were elevated significantly in patients with pancreatic cancer versus controls, whereas no differences were observed in other Ig isotypes (IgG, IgM, IgA). Flow cytometry and immunofluorescence microscopy demonstrated similar presence of IgG and IgE pancreatic cancer Igs. However, Western blot analysis indicated differences in IgG and IgE antigen-specific antibodies; IgE antibody recognized a 50 kD protein. ADCC studies demonstrated that serum and purified IgE-mediated cytotoxicity against pancreatic cancer cells, effects which were reversed with anti-IgE neutralizing antibody and IgE depletion (immunoaffinity); greater cytotoxicity was observed in patient serum when compared with healthy controls. These data suggest that IgE and sCD23 may serve as useful biomarkers for patients with pancreatic cancer and may be important in the immune response to this disease in that IgE-directed therapy may help to direct treatment.

Induction of apoptosis in tumor cells as a mechanism of tumor growth reduction in allergic mice

Cancer is the leading cause of mortality worldwide. Analysis of epidemiological data has revealed a negative relationship between allergic conditions and cancer incidence. This study addresses the effects of chronic antigen ingestion by sensitized mice (allergy) on Ehrlich tumor growth in mouse footpad. Mice were sensitized (allergic) or not (sham) with ovalbumin and challenged orally with egg white solution. After one week of oral challenge, all mice were inoculated with experimental Ehrlich tumor (EET) cells in the footpad, and tumor growth was evaluated for 21 days. A decrease in tumor growth occurred, as assessed by paw thickness in the allergic group, which was associated with smaller areas of necrosis, reduced infiltration of neutrophils, and reduced levels of IFN-gamma, IL-4, and IL-10. Although, the tumor proliferation rate was similar in both groups, an increase in apoptosis occurred in allergic mice. In conclusion, analysis of the data obtained allows us to suggest that a concomitant allergic condition would reduce tumor progression through increased tumor cell apoptosis, accompanied by reduced areas of necrosis at the tumor site. Indeed, such findings suggested a possible mechanism for the reduced cancer incidence observed in allergic individuals.

Allergies: their role in cancer prevention

The nature of the biological relationships between cancers and allergies has intrigued researchers and health care providers for five decades. Three hypotheses have been proposed: antigenic stimulation predicts positive associations between cancers and allergies (i.e., allergy sufferers are more likely to get cancer), whereas immunosurveillance and prophylaxis predict inverse associations (i.e., allergy sufferers are less likely to get cancer). Immunosurveillance predicts inverse associations for cancers of all tissues and organ systems, and prophylaxis predicts inverse associations specifically for cancers of tissues and organ systems that interface with the external environment. To comparatively evaluate these hypotheses, we comprehensively reviewed the literature on cancer and allergies. We located 148 papers published from 1955 through 2006 that reported results of 463 studies of relationships between patients' histories of 11 specific allergies and cancers of 19 tissues and organ systems, and 183 studies of patients' histories of multiple allergies in relation to various types/sites of cancers. Analyses of these studies revealed that (1) frequencies of positive, inverse, and null allergy-cancer associations differed considerably among cancers of different tissues and organ systems; (2) more than twice as many studies reported inverse allergy-cancer associations as reported positive associations; (3) inverse associations were particularly common for cancers of the mouth and throat, brain glia, colon and rectum, pancreas, skin, and cervix but (4) particularly rare for cancers of the breast, prostate, and brain meninges, and for myeloma, non-Hodgkin's lymphoma, and myelocytic leukemia; (5) lung cancer was positively associated with asthma but inversely associated with other allergies; (6) inverse associations with allergies were more than twice as common for cancers of nine tissues and organ systems that interface with the external environment compared to cancers of nine tissues and organ systems that do not interface with the external environment; and (7) eczema, hives, and allergies to animal dander and food were most frequently inversely associated with cancers of tissues that interface with the external environment. Taken together, these results are more consistent with the prophylaxis hypothesis than the two alternatives. IgE is a widespread and ancient immunoglobulin isotype in mammals, occurring among all known marsupials, monotremes, and eutherians. The IgE system and its associated allergy symptoms may serve a common protective function: the rapid expulsion of pathogens, dangerous natural toxins, and other carcinogenic antigens before they can trigger malignant neoplasia in exposed tissues.

Lifestyle, dietary, and medical history factors associated with pancreatic cancer risk in Ontario, Canada

OBJECTIVES

Pancreatic adenocarcinoma has one of the worst survival rates of all the cancers. Established risk factors for this malignancy are smoking, body mass index (BMI) and family history of pancreatic cancer. Findings are inconsistent regarding pancreatitis, diabetes, allergies, intake of fruit, vegetables, red meat, alcohol, caffeine, vitamin C, calcium, and folate supplements. Possible pancreatic cancer risk factors were evaluated within the population-based Ontario Pancreas Cancer Study.

METHODS

Pathologically confirmed pancreatic cancer cases (n = 422) were identified from the Ontario Cancer Registry between 2003 and 2007. Controls (n = 312) were recruited through random digit dialing. Data were collected using self-administered questionnaires. Multivariate logistic regression was used to obtain odds ratios.

RESULTS

Smoking, BMI, family history of pancreatic cancer, and caffeine were significantly associated with increased pancreatic cancer risk, while fruit intake and allergies significantly decreased risk. No other significant associations were observed in the multivariate model. Effect modification by smoking status was suggested for caffeine, family history of pancreatic cancer, BMI, and fruit.

CONCLUSIONS

This study further clarifies the association between several lifestyle, dietary and medical history factors, and pancreatic cancer risk, many of which are potentially modifiable. Possible effect modification by smoking status should be further explored in future etiologic studies.

Past medical conditions and K-ras mutations in pancreatic ductal adenocarcinoma: a hypothesis-generating study

BACKGROUND

In pancreatic ductal adenocarcinoma (PDA) evidence on the etiopathogenic role of past medical conditions in the occurrence and persistence of K-ras mutations is scant.

METHODS

Incident cases of PDA were interviewed face-to-face about past medical history and other factors. Logistic regression was used to compare PDA cases (n = 120) with wild-type and mutated K-ras tumors (case-case study).

RESULTS

Patients with wild-type K-ras tumors were more likely to have a prior diagnosis of pancreatitis (Odds ratio [OR] = 6.11, p = 0.041). Diabetes mellitus (DM) was non-significantly more common among cases with a K-ras wild-type tumor, and the OR for DM of >6 years of duration was 4.54 (p = 0.39). Patients with wild-type K-ras were significantly more likely to have had a surgically treated peptic ulcer (OR = 9.03, p = 0.027). The probability of having a K-ras wild-type tumor increased with the number of medical conditions (p for trend = 0.012); the corresponding OR for two or more medical conditions was 4.46 (95% CI: 1.37-14.50).

CONCLUSIONS

Results raise the hypothesis that pancreatitis and possibly peptic ulcer might influence pancreatic carcinogenesis through pathways independent of K-ras mutation, perhaps related to growth factors or mediators of the inflammatory response. Large unselected studies should be conducted to refute or replicate our findings.

AllergoOncology: the role of IgE-mediated allergy in cancer

Epidemiological studies have suggested inverse associations between allergic diseases and malignancies. As a proof of concept for the capability of immunoglobulin E (IgE) to destruct tumor cells, several experimental strategies have evolved to specifically target this antibody class towards relevant tumor antigens. It could be demonstrated that IgE antibodies specific to overexpressed tumor antigens have been superior to any other immunoglobulin class with respect to antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) reactions. In an alternative approach, IgE nonspecifically attached to tumor cells proved to be a powerful adjuvant establishing tumor-specific immune memory. Active Th2 immunity could also be achieved by applying an oral immunization regimen using mimotopes, i.e. epitope mimics of tumor antigens. The induced IgE antibodies could be cross-linked by live tumor cells leading to tumoricidic mediator release. Thus, IgE antibodies may not only act in natural tumor surveillance, but could possibly also be exploited for tumor control in active and passive immunotherapy settings. Thereby, eosinophils, mast cells and macrophages can be armed with the cytophilic IgE and become potent anti-tumor effectors, able to trace viable tumor cells in the tissues. It is strongly suggested that the evolving new field AllergoOncology will give new insights into the role of IgE-mediated allergy in malignancies, possibly opening new avenues for tumor therapy.

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

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

Allergies, variants in IL-4 and IL-4R alpha genes, and risk of pancreatic cancer

BACKGROUND

Several studies in epidemiology indicate that risk of pancreatic cancer is reduced in individuals with allergies. Although genes have been identified that are critical in allergic response, polymorphisms in these genes have not been studied in relation to risk of pancreatic cancer. We hypothesized that variants in these genes are related to risk.

METHODS

We investigated the association of allergies and pancreatic cancer in a hospital-based case-control study with 405 cases and 212 controls. In a subgroup of 149 cases and 135 controls, we studied the association of variants in IL-4 (C-589T, G3017T) and IL-4R alpha (Gln576Arg) with allergies and with risk of pancreatic cancer.

RESULTS

We found reduced risk of pancreatic cancer associated with allergies, with adjusted odds ratios of 0.58 (95% CI 0.40-0.84) for any allergies, 0.45 (95% CI 0.29-0.70) for hay fever, and 0.43 (95% CI 0.23-0.80) for animals. The minor allele at each locus studied was associated with reduced risk of allergies in controls, leading us to hypothesize that they would be associated with increased risk of pancreatic cancer. Overall, there was no association between the genotypes studied and risk of pancreatic cancer. In analyses within strata defined by presence or absence of allergies, there were differences in risk associated with genotype for IL-4 G3017T: there was slightly increased risk among those with allergies and reduced risk among those without allergies.

CONCLUSIONS

The consistent association of allergies with risk of pancreatic cancer and these results suggest that associations between variants in genes related to allergic response and pancreatic cancer warrant further study.

The association between allergies and cancer: what is currently known?

OBJECTIVE

To provide an overview of what is currently known about the relationship between allergies and cancer.

DATA SOURCES

Publications were selected from a systematic review of the English-language literature from established databases (eg, MEDLINE, EBSCO) and the references of materials identified through these databases.

STUDY SELECTION

Publications assessing the association between asthma, hay fever, or other allergy-related diseases and cancer were included in this review.

RESULTS

Individuals with any type of allergy have a decreased risk for cancer (compared with the general population), including glioma, colorectal cancer, cancer of the larynx, non-Hodgkin lymphoma, cancer of the esophagus, oral cancer, pancreatic cancer, stomach cancer, and uterine body cancer. However, an increased risk for bladder cancer, lymphoma, myeloma, and prostate cancer exists among those with allergies. Studies that involve breast cancer, leukemia, lung cancer, melanoma, and thyroid cancer have shown no association or conflicting results related to allergies. More research is needed before conclusions can be made about the relation between allergies and Kaposi sarcoma, liver cancer, and cancer of the ovaries.

CONCLUSIONS

The association between allergies and cancer is site specific. Further research is needed to verify these results and to determine why such associations exist.

Lifestyle, occupational, and reproductive factors in relation to pancreatic cancer risk

OBJECTIVES

This study examined the epidemiology of pancreatic cancer in Egypt.

METHODS

We obtained detailed information on smoking, occupational, medical, and reproductive histories from 194 pancreatic cancer cases and 194 controls.

RESULTS

Compared with not smoking, smoking cigarettes alone or in conjunction with other smoking methods (eg, water pipe, cigar) was associated with an increased risk (odds ratio [OR], 4.5 and 7.8; 95% confidence interval [95% CI], 1.9-10.7 and 3.0-20.6, respectively). Passive smoking was also a significant risk factor (OR, 6.0; 95% CI, 2.4-14.8). The risk of pancreatic cancer was elevated among subjects exposed to pesticides (OR, 2.6; 95% CI, 0.97-7.2). A prior diagnosis of diabetes mellitus for a period of 10 years was associated with higher risk (OR, 5.4; 95% CI, 1.5-19.9). For women, having 7 or more live births and lactating for 144 months or longer were associated with a reduced risk (OR, 0.5 and 0.2; 95% CI, 0.2-1.3 and 0.1-0.9, respectively). No association was found between family history, allergy, or obesity and pancreatic cancer in Egypt.

CONCLUSIONS

Multiple tobacco consumption methods, passive smoking, pesticide exposures, and diabetes are associated with an increased risk for pancreatic cancer. Prolonged lactation and increased parity are associated with a reduced risk for pancreatic cancer.

Does anti-IgE therapy help in asthma? Efficacy and controversies

Omalizumab, a humanized monoclonal antibody against IgE, is clinically efficacious when it neutralizes almost all free IgE and reduces IgE receptors on basophils and mast cells. Asthmatic subjects on inhaled corticosteroids who are treated with omalizumab as an add-on therapy experience only modest benefits in symptoms and perhaps in quality of life, but the most significant effects are reductions in airway inflammation and in exacerbation rate. Airway obstruction and hyperresponsiveness do not change significantly. Although the magnitude of the beneficial effects is small, they are observed even in the most severe cases, particularly the reduction in exacerbation rate. The safety profile of omalizumab is very encouraging, although phase IV studies are ongoing to clarify the incidence of neoplasias. Because of its cost, omalizumab therapy may be most cost-effective in patients with severe and refractory asthma, particularly those with frequent exacerbations requiring hospital care. Further clinical studies are now evaluating the best place for omalizumab in the algorithm of asthma management.

History of allergies and risk of glioma in adults

Epidemiological studies have consistently reported an inverse association between a history of allergic disease and risk of glioma. The reason for this association is unclear, and there is a lack of studies with the detail and size to explore the association in depth. We conducted a UK population-based case-control study with 965 glioma cases and 1,716 controls to investigate glioma risk in relation to allergic disease. Risk was reduced in subjects reporting a history of asthma (odds ratio (OR) = 0.71, 95% confidence interval (CI): 0.54-0.92), hay fever (OR = 0.73, 95% CI: 0.59-0.90), eczema (OR = 0.74, 95% CI: 0.56-0.97) and other allergies (OR = 0.65, 95% CI: 0.47-0.90). Risk was reduced for all the main histological groups. There was no significant trend of risk with age, at the onset of each condition, or the number of conditions reported. Risk reductions were strongest for asthma or hay fever with recent onset. Risk in asthmatic subjects was not related to frequency of use of antiasthmatic drugs, but was significantly reduced for use of antiallergenic medication among subjects with hay fever. The study showed an inverse association of glioma risk with allergic disease. Possible reasons for the association, as well as potential immunological aetiology, include confounding, bias and reverse causality.

An overview of the association between allergy and cancer

Numerous epidemiological studies have evaluated some aspect of the association between a history of allergy and cancer occurrence. In this article, an overview of the epidemiological evidence is presented with a discussion of a number of methodological issues important in this area of study. Literature searches were conducted using the MEDLINE database from 1966 through to August 2005 to identify articles that explored a personal history of allergic disorders as a risk factor for cancer. Although it is difficult to draw conclusions between allergy and cancer at many sites because of insufficient evidence or a lack of consistency both within and among studies completed to date, strong inverse associations have been reported for pancreatic cancer and glioma, whereas lung cancer was positively associated with asthma. Additional studies are needed to confirm these finding and to address the limitations of previous studies, including the validity and reliability of exposure measures and control for confounding. Further, large prospective studies using cancer incidence would be particularly useful, including studies using biological markers of allergic status to reduce potential misclassification and to confirm the results of previous studies based on self-report. There is also a need for further basic research to clarify a potential mechanism, should an association exist.

Epidemiology and risk factors for pancreatic cancer

Pancreas cancer is considered an 'orphan' cancer because of its relative low incidence. Unfortunately even with early diagnosis, mortality rates are high, explaining why, despite the low incidence, it ranks eighth in a world listing of cancer mortality. International incidence rates vary in different countries, implying that environmental factors are important. Of these factors, smoking is the most well documented etiologic agent, explaining about 25% of all cases. Dietary factors may be important, but it has been difficult to define specific items which either increase or decrease the risk of pancreatic cancer. Since the incidence of pancreas cancer is so strongly age-dependent, we can anticipate an increasing number of patients as the population of most Western countries ages.