Reduced immunoglobulin E and allergy among adults with glioma compared with controls

Association of immunoglobulin E levels with glioma risk and survival

Background

Previous epidemiological studies have reported an association of serum immunoglobulin E (IgE) levels with reduced glioma risk, but the association between IgE and glioma prognosis is not well characterized. This study aimed to examine how sex, tumor subtype, and IgE class modulate the association of serum IgE levels with glioma risk and survival.

Methods

We conducted a case-control study using participants from the University of California, San Francisco Adult Glioma Study (1997-2010). Serum IgE levels for total, respiratory and food allergy were measured in adults diagnosed with glioma (n=1,696) and cancer-free controls (n=1,135) matched based on age, sex, and race/ethnicity. Logistic regression was adjusted for patient demographics to assess the association between IgE levels and glioma risk. Multivariable Cox regression adjusted for patient-specific and tumor-specific factors compared survival between the elevated and normal IgE groups.

Results

Elevated total IgE was associated with reduced risk of IDH wildtype (OR=0.65, 95% CI: 0.54-0.78) and IDH mutant glioma (OR=0.65, 95% CI: 0.50-0.85). In multivariable Cox regression, elevated respiratory IgE was associated with improved survival for IDH wildtype glioma (HR=0.78, 95% CI: 0.67-0.91). The reduction in mortality risk was more pronounced in females (HR=0.71, 95% CI: 0.53-0.96) than in males (HR=0.80, 95% CI: 0.66-0.97), with improvements in median survival of 6.2 months (P<.001) and 1.6 months (P=0.003), respectively.

Conclusion

Elevated serum IgE was associated with improved prognosis for IDH wildtype glioma, with a more pronounced protective effect in females. These results suggest a possible sexual dimorphism and antitumor activity of IgE-mediated immune responses.

Alkylating agents are possible inducers of glioblastoma and other brain tumors

Epidemiological evidence of an association between exposure to chemical carcinogens and an increased risk for development of glioblastoma (GBM) is limited to weak statistical associations in cohorts of firefighters, farmers, residents exposed to air pollution, and soldiers exposed to toxic chemicals (e.g., military burn pits, oil-well fire smoke). A history of ionizing radiation therapy to the head or neck is associated with an increased risk of GBM. Ionizing radiation induces point mutations, frameshift mutations, double-strand breaks, and chromosomal insertions or deletions. Mutational profiles associated with chemical exposures overlap with the broad mutational patterns seen with ionizing radiation. Data on 16 agents (15 chemicals and radio frequency radiation) that induced tumors in the rodent brain were extracted from 602 Technical Reports on 2-years cancer bioassays found in the National Toxicology Program database. Ten of the 15 chemical agents that induce brain tumors are alkylating agents. Three of the 15 chemical agents have idiosyncratic structures and might be alkylating agents. Only two of the 15 chemical agents are definitively not alkylating agents. The rat model is thought to be of possible relevance to humans suggesting that exposure to alkylating chemicals should be considered in epidemiology studies on GBM and other brain tumors.

Genetic predisposition to altered blood cell homeostasis is associated with glioma risk and survival

Glioma is a highly fatal brain tumor comprised of molecular subtypes with distinct clinical trajectories. Observational studies have suggested that variability in immune response may play a role in glioma etiology. However, their findings have been inconsistent and susceptible to reverse causation due to treatment effects and the immunosuppressive nature of glioma. We applied genetic variants associated (p<5×10-8) with blood cell traits to a meta-analysis of 3418 glioma cases and 8156 controls. Genetically predicted increase in the platelet to lymphocyte ratio (PLR) was associated with an increased risk of glioma (odds ratio (OR)=1.25, p=0.005), especially in IDH-mutant (IDHmut OR=1.38, p=0.007) and IDHmut 1p/19q non-codeleted (IDHmut-noncodel OR=1.53, p=0.004) tumors. However, reduced glioma risk was observed for higher counts of lymphocytes (IDHmut-noncodel OR=0.70, p=0.004) and neutrophils (IDHmut OR=0.69, p=0.019; IDHmut-noncodel OR=0.60, p=0.009), which may reflect genetic predisposition to enhanced immune-surveillance. In contrast to susceptibility, there was no association with survival in IDHmut-noncodel; however, in IDHmut 1p/19q co-deleted tumors, we observed higher mortality with increasing genetically predicted counts of lymphocytes (hazard ratio (HR)=1.65, 95% CI: 1.24-2.20), neutrophils (HR=1.49, 1.13-1.97), and eosinophils (HR=1.59, 1.18-2.14). Polygenic scores for blood cell traits were also associated with tumor immune microenvironment features, with heterogeneity by IDH status observed for 17 signatures related to interferon signaling, PD-1 expression, and T-cell/Cytotoxic responses. In summary, we identified novel, immune-mediated susceptibility mechanisms for glioma with potential disease management implications.

The Epidemiology of Central Nervous System Tumors

This article reviews the current epidemiology of central nervous system tumors. Population-level basic epidemiology, nationally and internationally, and current understanding of germline genetic risk are discussed, with a focus on known and well-studied risk factors related to the etiology of central nervous system tumors.

Epidemiology of Brain and Other CNS Tumors

PURPOSE OF REVIEW

Brain and other central nervous system (CNS) tumors, while rare, cause significant morbidity and mortality across all ages. This article summarizes the current state of the knowledge on the epidemiology of brain and other CNS tumors.

RECENT FINDINGS

For childhood and adolescent brain and other CNS tumors, high birth weight, non-chromosomal structural birth defects and higher socioeconomic position were shown to be risk factors. For adults, increased leukocyte telomere length, proportion of European ancestry, higher socioeconomic position, and HLA haplotypes increase risk of malignant brain tumors, while immune factors decrease risk. Although no risk factor accounting for a large proportion of brain and other CNS tumors has been discovered, the use of high throughput "omics" approaches and improved detection/measurement of environmental exposures will help us refine our current understanding of these factors and discover novel risk factors for this disease.

History of atopy confers improved outcomes in IDH mutant and wildtype lower grade gliomas

PURPOSE

A history of atopy or allergy has been shown to be protective against the development of glioma, however the effect of atopy on patient outcomes, especially in conjunction with the survival benefit associated with IDH mutation, has not yet been investigated, and is the focus of the study we present here.

METHODS

Low grade glioma (LGG) data from the TCGA was downloaded, along with IDH, TERT, 1p/19q and ATRX mutational status and genetic alterations. History of asthma, eczema, hay fever, animal, or food allergies, as documented in TCGA, was used to determine patient atopy status. Patients with missing variables were excluded from the study.

RESULTS

374 LGG studies were included. Patients with a history of atopy demonstrated longer overall survival (OS) compared to those without (145.3 vs. 81.5 months, p = 00.0195). IDH mutant patients with atopy had longer OS compared those without atopy (158.8 vs. 85 months, p = 0.035). Multivariate cox regression analysis demonstrated that the effects of atopy on survival were independent of IDH and histological grade, (p = 0.002, HR 0.257, 95% 0.109-0.604), (p =  < 0.001, HR 0.217, 95% 0.107-0.444), and (p = 0.004, HR 2.72, 95% 1.373-5.397), respectively. In terms of treatment outcomes, patients with atopy did not differ in treatment response compared to their counterpart. Pathway analysis demonstrated an upstream activation of the BDNF pathway (p = 0.00027).

CONCLUSION

A history of atopy confers a survival benefit in patients with diffuse low-grade glioma. Activation of the BDNF pathway may drive the observed differences.

Clinical and immunological allergy assessment in cancer patients

Cancer is associated with immunodeficiency, while allergies result from immune system hyperactivity mediated by cytokines and immunoglobulins. The purpose of this study was to determine the relationship between immune environment of specific cancers and allergies, emphasizing cytokines related to Th1 and Th2 responses associated with IgE. 80 adults were distributed into two groups: control (n = 20) and cancer (n = 60), distributed in three subgroups (n = 20), head and neck, stomach, and prostate cancers. This study compared Th1 (IL-2) and Th2 (IL-4) parameters, anti-inflammatory, pro-inflammatory, or regulatory profile regarding both IgE levels and reported allergies, by means of clinical manifestations and IgE, IL-1β, IL-2, IL-4, IL-17, and TGF-β serum concentration. Clinically allergies were observed in 50% of the control group and in 20% of the cancer group (p = 0.009). IL-2 cytokine and TGF-β concentrations were higher in the patients with cancer as compared to the control (p < 0.005). However, there were IL-4, IL-17, and IL-1β decreases in the patients with cancer (p < 0.05). No correlation was observed between the cytokines studied and IgE and clinically proven allergies in both investigated groups. There was an inverse association between cancer and clinical allergy manifestations. In head and neck, stomach, and prostate cancers, an immunosuppressive serum tumor environment was predominant. There was no difference in cytokines related to Th1 and Th2 parameters in relation to IgE. No correlation was found between clinically proved allergies and immunity markers related to the same allergens.

Insights from IgE Immune Surveillance in Allergy and Cancer for Anti-Tumour IgE Treatments

IgE, the predominant antibody class of the allergic response, is known for its roles in protecting against parasites; however, a growing body of evidence indicates a significant role for IgE and its associated effector cells in tumour immunosurveillance, highlighted by the field of AllergoOncology and the successes of the first-in-class IgE cancer therapeutic MOv18. Supporting this concept, substantial epidemiological data ascribe potential roles for IgE, allergy, and atopy in protecting against specific tumour types, with a corresponding increased cancer risk associated with IgE immunodeficiency. Here, we consider how epidemiological data in combination with functional data reveals a complex interplay of IgE and allergy with cancer, which cannot be explained solely by one of the existing conventional hypotheses. We furthermore discuss how, in turn, such data may be used to inform future therapeutic approaches, including the clinical management of different patient groups. With epidemiological findings highlighting several high-risk cancer types protected against by high IgE levels, it is possible that use of IgE-based therapeutics for a range of malignant indications may offer efficacy to complement that of established IgG-class antibodies.

Sex differences in health and disease: A review of biological sex differences relevant to cancer with a spotlight on glioma

The influence of biological sex differences on human health and disease, while being increasingly recognized, has long been underappreciated and underexplored. While humans of all sexes are more alike than different, there is evidence for sex differences in the most basic aspects of human biology and these differences have consequences for the etiology and pathophysiology of many diseases. In a disease like cancer, these consequences manifest in the sex biases in incidence and outcome of many cancer types. The ability to deliver precise, targeted therapies to complex cancer cases is limited by our current understanding of the underlying sex differences. Gaining a better understanding of the implications and interplay of sex differences in diseases like cancer will thus be informative for clinical practice and biological research. Here we review the evidence for a broad array of biological sex differences in humans and discuss how these differences may relate to observed sex differences in various diseases, including many cancers and specifically glioblastoma. We focus on areas of human biology that play vital roles in healthy and disease states, including metabolism, development, hormones, and the immune system, and emphasize that the intersection of sex differences in these areas should not go overlooked. We further propose that mathematical approaches can be useful for exploring the extent to which sex differences affect disease outcomes and accounting for those in the development of therapeutic strategies.

Glioblastoma: Is There Any Blood Biomarker with True Clinical Relevance?

Glioblastoma (GBM) is the most frequent malignant primary brain tumor in adults, characterized by a highly aggressive, inflammatory and angiogenic phenotype. It is a remarkably heterogeneous tumor at several levels, including histopathologically, radiographically and genetically. The 2016 update of the WHO Classification of Tumours of the Central Nervous System highlighted molecular parameters as paramount features for the diagnosis, namely IDH1/2 mutations that distinguish primary and secondary GBM. An ideal biomarker is a molecule that can be detected/quantified through simple non- or minimally invasive methods with the potential to assess cancer risk; promote early diagnosis; increase grading accuracy; and monitor disease evolution and treatment response, as well as fundamentally being restricted to one aspect. Blood-based biomarkers are particularly attractive due to their easy access and have been widely used for various cancer types. A number of serum biomarkers with multiple utilities for glioma have been reported that could classify glioma grades more precisely and provide prognostic value among these patients. At present, screening for gliomas has no clinical relevance. This is because of the low incidence, the lack of sensitive biomarkers in plasma, and the observation that gliomas may develop apparently de novo within few weeks or months. To the best of our knowledge, there is no routine use of a serum biomarker for clinical follow-up. The purpose of this paper is to review the serum biomarkers described in the literature related to glioblastoma and their possible relationship with clinical features.

Autoimmune diseases and immunosuppressive therapy in relation to the risk of glioma

Effectors from the immune system can modulate the course and possibly the early development of gliomas. We, therefore, hypothesized that autoimmune diseases associated with increased immune‐surveillance may also modulate the risk of human glioma. To test this hypothesis, we used data from the well‐validated Clinical Practice Research Datalink (CPRD) GOLD from the UK to analyze the association of immune‐related disorders or use of immunosuppressive drugs and the risk of glioma. We identified 3112 incident glioma cases diagnosed between 1995 and 2017. We randomly selected up to 10 controls, matching them to glioma cases on age, sex, index date, general practice, and number of years of active history in the database prior to the index date. We performed conditional logistic regression analyses to estimate Odds Ratios (ORs) of glioma among those exposed to allergies, autoimmune diseases, and immunosuppressive drugs. Overall, we found no materially altered association between a history of any autoimmune disease (OR 0.98, 95% CI 0.86‐1.11), allergy (OR 0.97, 95% CI 0.89‐1.05), or use of immunosuppressive drugs and the risk of glioma. However, subgroup analyses among younger patients found a statistically significant increased risk of glioma in patients with a history of inflammatory bowel disease (IBD) (OR 2.59, 95% CI 1.31‐5.12). There was also an inverse association between asthma and risk of glioma in patients with longer survival (OR 0.73, 95% CI 0.58‐0.91) and between long‐term duration diabetes and risk of glioma (OR 0.71, 95% CI 0.53‐0.96).

Immune factors preceding diagnosis of glioma: a Prostate Lung Colorectal Ovarian Cancer Screening Trial nested case-control study

Background

Epidemiological studies of adult glioma have identified genetic and environmental risk factors, but much remains unclear. The aim of the current study was to evaluate anthropometric, disease-related, and prediagnostic immune-related factors for relationship with glioma risk.

Methods

We conducted a nested case–control study among the intervention arm of the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial. One hundred and twenty-four glioma cases were identified and each matched to four controls. Baseline characteristics were collected at enrollment and were evaluated for association with glioma status. Serum specimens were collected at yearly intervals and were analyzed for immune-related factors including TGF-β1, TNF-α, total IgE, and allergen-specific IgE. Immune factors were evaluated at baseline in a multivariate conditional logistic regression model, along with one additional model that incorporated the latest available measurement.

Results

A family history of glioma among first-degree relatives was associated with increased glioma risk (OR = 4.41, P = .002). In multivariate modeling of immune factors at baseline, increased respiratory allergen-specific IgE was inversely associated with glioma risk (OR for allergen-specific IgE > 0.35 PAU/L: 0.59, P = .03). A logistic regression model that incorporated the latest available measurements found a similar association for allergen-specific IgE (P = .005) and showed that elevated TGF-β1 was associated with increased glioma risk (P-value for trend <.0001).

Conclusion

The results from this prospective prediagnostic study suggest that several immune-related factors are associated with glioma risk. The association observed for TGF-β1 when sampling closer to the time of diagnosis may reflect the nascent brain tumor’s feedback on immune function.

Genetic and molecular epidemiology of adult diffuse glioma

The WHO 2007 glioma classification system (based primarily on tumour histology) resulted in considerable interobserver variability and substantial variation in patient survival within grades. Furthermore, few risk factors for glioma were known. Discoveries over the past decade have deepened our understanding of the molecular alterations underlying glioma and have led to the identification of numerous genetic risk factors. The advances in molecular characterization of glioma have reframed our understanding of its biology and led to the development of a new classification system for glioma. The WHO 2016 classification system comprises five glioma subtypes, categorized by both tumour morphology and molecular genetic information, which led to reduced misclassification and improved consistency of outcomes within glioma subtypes. To date, 25 risk loci for glioma have been identified and several rare inherited mutations that might cause glioma in some families have been discovered. This Review focuses on the two dominant trends in glioma science: the characterization of diagnostic and prognostic tumour markers and the identification of genetic and other risk factors. An overview of the many challenges still facing glioma researchers is also included.

Allergic Signs in Glioma Pathology: Current Knowledge and Future Perspectives

Historically restrained to immune defense against parasite infections, allergic inflammation has been recently rediscovered to protect from a wide array of environmental triggers, such as xenobiotics and carcinogens, which can induce DNA damage and ultimately lead to cancer development. Moreover, cells and mediators typical of allergic responses can importantly modulate the tissue inflammatory milieu, which represents a crucial gatekeeper towards the acquisition of malignancy by cancer cells through immune escape. Numerous studies have described an inverse association between allergies and glioma development. Mast cells, key players of allergic reactions, have been recently found at increased numbers in glioblastoma multiforme (GBM), the most common and lethal primary brain tumor, and they have been implicated in GBM pathogenesis. In this review, we summarize epidemiological studies and discuss the main evidence highlighting a potential interplay between allergic responses, and glioma formation and progression. Last, we draw future lines of research for better clarification whether and through which mechanisms allergic inflammation might impact on gliomagenesis. The comprehension of the immune mechanisms favoring or counteracting tumor growth might open the path to novel immunotherapy approaches.

Serially measured pre-diagnostic levels of serum cytokines and risk of brain cancer in active component military personnel

Background

There is growing evidence that history of allergic or autoimmune disease is associated with reduced risk of glioma, but few prospective studies have explored the biological basis. To assess associations with immune conditions and levels of 14 cytokines in serial prediagnostic serum samples, we conducted a study of glioma/brain cancer nested in a cohort of active component military personnel.

Methods

A total of 457 case-control sets were ascertained from the Department of Defense (DoD) Automated Central Tumour Registry, Defense Medical Surveillance System (DMSS) database, and DoD Serum Repository. These were individually matched on sex, race/ethnicity, birth year, number of serum samples (1, 2 or 3), and date(s) of sample collection. We obtained diagnoses of pre-existing immune-related conditions from the DMSS database and measured cytokines using Meso Scale Discovery assays. Statistical analyses included conditional logistic regression.

Results

Overall association between glioma and prior immune-related conditions was null. Higher levels of IL-15 and IL-16 were independently associated with lower glioma risks (P_trend = 0.002 and P_trend = 0.001); both associations were more pronounced in individuals with prior immune conditions (P_{heterogeneity} = 0.0009 and P_{heterogeneity} = 0.031).

Conclusions

Associations with pre-diagnostic levels of IL-15 and IL-16 and their modification by diagnosis of immune-related conditions support the importance of immune alterations in glioma aetiology years before diagnosis.

Repurposing old drugs in oncology: Opportunities with clinical and regulatory challenges ahead

WHAT IS KNOWN AND OBJECTIVE

In order to expedite the availability of drugs to treat cancers in a cost-effective manner, repurposing of old drugs for oncological indications is gathering momentum. Revolutionary advances in pharmacology and genomics have demonstrated many old drugs to have activity at novel antioncogenic pharmacological targets. We decided to investigate whether prospective studies support the promises of nonclinical and retrospective clinical studies on repurposing three old drugs, namely metformin, valproate and astemizole.

METHODS

We conducted an extensive literature search through PubMed to gather representative nonclinical and retrospective clinical studies that investigated the potential repurposing of these three drugs for oncological indications. We then searched for prospective studies aimed at confirming the promises of retrospective data.

RESULTS AND DISCUSSION

While evidence from nonclinical and retrospective clinical studies with these drugs appears highly promising, large scale prospective studies are either lacking or have failed to substantiate this promise. We provide a brief discussion of some of the challenges in repurposing. Principal challenges and obstacles relate to heterogeneity of cancers studied without considering their molecular signatures, trials with small sample size and short duration, failure consider issues of ethnicity of study population and effective antioncogenic doses of the drug studied.

WHAT IS NEW AND CONCLUSION

Well-designed prospective studies demonstrating efficacy are required for repurposing old drugs for oncology indications, just as they are for new chemical entities for any indication. Early and ongoing interactions with regulatory authorities are invaluable. We outline a tentative framework for a structured approach to repurposing old drugs for novel indications in oncology.

Impact of atopy on risk of glioma: a Mendelian randomisation study

BACKGROUND

An inverse relationship between allergies with glioma risk has been reported in several but not all epidemiological observational studies. We performed an analysis of genetic variants associated with atopy to assess the relationship with glioma risk using Mendelian randomisation (MR), an approach unaffected by biases from temporal variability and reverse causation that might have affected earlier investigations.

METHODS

Two-sample MR was undertaken using genome-wide association study data. We used single nucleotide polymorphisms (SNPs) associated with atopic dermatitis, asthma and hay fever, IgE levels, and self-reported allergy as instrumental variables. We calculated MR estimates for the odds ratio (OR) for each risk factor with glioma using SNP-glioma estimates from 12,488 cases and 18,169 controls, using inverse-variance weighting (IVW), maximum likelihood estimation (MLE), weighted median estimate (WME) and mode-based estimate (MBE) methods. Violation of MR assumptions due to directional pleiotropy were sought using MR-Egger regression and HEIDI-outlier analysis.

RESULTS

Under IVW, MLE, WME and MBE methods, associations between glioma risk with asthma and hay fever, self-reported allergy and IgE levels were non-significant. An inverse relationship between atopic dermatitis and glioma risk was found by IVW (OR 0.96, 95% confidence interval (CI) 0.93-1.00, P = 0.041) and MLE (OR 0.96, 95% CI 0.94-0.99, P = 0.003), but not by WME (OR 0.96, 95% CI 0.91-1.01, P = 0.114) or MBE (OR 0.97, 95% CI 0.92-1.02, P = 0.194).

CONCLUSIONS

Our investigation does not provide strong evidence for relationship between atopy and the risk of developing glioma, but findings do not preclude a small effect in relation to atopic dermatitis. Our analysis also serves to illustrate the value of using several MR methods to derive robust conclusions.

Allergic conditions and risk of glioma and meningioma in the CERENAT case-control study

Inverse association between allergic conditions and glioma risk has been consistently reported in epidemiological studies with little attention paid to potential environmental confounders; the association with meningioma risk is less consistent. We examined the association between allergy history and risk of glioma and meningioma in adults using data from the CERENAT (CEREbral tumors: a NATional study) multicenter case-control study carried out in 4 areas in France in 2004-2010. Participants' histories of doctor-diagnosed allergic asthma, eczema, rhinitis/hay fever and other allergic conditions were collected at onset through a detailed questionnaire delivered in a face-to-face interview. Conditional logistic regression for matched sets was adjusted for participants' educational level and mobile phone use. A total of 273 glioma cases, 218 meningioma cases and 982 matched controls selected from the local electoral rolls were analyzed. A significant inverse association was found between glioma and a history of any allergy (OR 0.52, 95% CI 0.36-0.75), with a dose-effect relationship with the number of allergic conditions reported (p-trend = 0.001) and a particularly strong association with hay fever/allergic rhinitis (OR 0.46, 95% CI 0.30-0.72). Interestingly, associations with glioma risk were more pronounced in women. For meningioma, no association was observed with overall or specific allergic conditions. Our findings confirmed the inverse association between allergic conditions and glioma risk but questioned the role of allergy in meningioma risk. Future research is needed to clarify the biological mechanism of overall allergy and allergic rhinitis on glioma and to confirm the different effect by gender.

Epidemiology of Brain Tumors

Brain tumors are the commonest solid tumor in children, leading to significant cancer-related mortality. Several hereditary syndromes associated with brain tumors are nonfamilial. Ionizing radiation is a well-recognized risk factor for brain tumors. Several industrial exposures have been evaluated for a causal association with brain tumor formation but the results are inconclusive. A casual association between the common mutagens of tobacco, alcohol, or dietary factors has not yet been established. There is no clear evidence that the incidence of brain tumors has changed over time. This article presents the descriptive epidemiology of the commonest brain tumors of children and adults.

Study designs may influence results: the problems with questionnaire-based case-control studies on the epidemiology of glioma

Glioma is a rare brain tumour with a very poor prognosis and the search for modifiable factors is intense. We reviewed the literature concerning risk factors for glioma obtained in case-control designed epidemiological studies in order to discuss the influence of this methodology on the observed results. When reviewing the association between three exposures, medical radiation, exogenous hormone use and allergy, we critically appraised the evidence from both case-control and cohort studies. For medical radiation and hormone replacement therapy (HRT), questionnaire-based case-control studies appeared to show an inverse association, whereas nested case-control and cohort studies showed no association. For allergies, the inverse association was observed irrespective of study design. We recommend that the questionnaire-based case-control design be placed lower in the hierarchy of studies for establishing cause-and-effect for diseases such as glioma. We suggest that a state-of-the-art case-control study should, as a minimum, be accompanied by extensive validation of the exposure assessment methods and the representativeness of the study sample with regard to the exposures of interest. Otherwise, such studies cannot be regarded as 'hypothesis testing' but only 'hypothesis generating'. We consider that this holds true for all questionnaire-based case-control studies on cancer and other chronic diseases, although perhaps not to the same extent for each exposure-outcome combination.

Atopy and Specific Cancer Sites: a Review of Epidemiological Studies

Mounting evidence appears to link asthma and atopy to cancer susceptibility. This review presents and discusses published epidemiological studies on the association between site-specific cancers and atopy. PubMed was searched electronically for publications between 1995 and 2015, and cited references were researched manually. Quantitative studies relating to atopy, allergy, or asthma and cancer were identified and tabulated. Despite many exposure-related limitations, patterns in the studies were observed. Asthma, specifically, has been observed to be a risk factor for lung cancer. A protective effect of atopic diseases against pancreatic cancer has been shown consistently in case-control studies but not in cohort studies. Allergy of any type appears to be protective against glioma and adult acute lymphoblastic leukemia. Most studies on atopic diseases and non-Hodgkin lymphoma or colorectal cancer reported an inverse association. The other sites identified had varying and non-significant outcomes. Further research should be dedicated to carefully defined exposure assessments of "atopy" as well as the biological plausibility in the association between atopic diseases and cancer.

Approaching a Scientific Consensus on the Association between Allergies and Glioma Risk: A Report from the Glioma International Case-Control Study

BACKGROUND

Several previous studies have found inverse associations between glioma susceptibility and a history of allergies or other atopic conditions. Some evidence indicates that respiratory allergies are likely to be particularly relevant with regard to glioma risk. Using data from the Glioma International Case-Control Study (GICC), we examined the effects of respiratory allergies and other atopic conditions on glioma risk.

METHODS

The GICC contains detailed information on history of atopic conditions for 4,533 cases and 4,171 controls, recruited from 14 study sites across five countries. Using two-stage random-effects restricted maximum likelihood modeling to calculate meta-analysis ORs, we examined the associations between glioma and allergy status, respiratory allergy status, asthma, and eczema.

RESULTS

Having a history of respiratory allergies was associated with an approximately 30% lower glioma risk, compared with not having respiratory allergies (mOR, 0.72; 95% confidence interval, 0.58-0.90). This association was similar when restricting to high-grade glioma cases. Asthma and eczema were also significantly protective against glioma.

CONCLUSION

A substantial amount of data on the inverse association between atopic conditions and glioma has accumulated, and findings from the GICC study further strengthen the existing evidence that the relationship between atopy and glioma is unlikely to be coincidental.

IMPACT

As the literature approaches a consensus on the impact of allergies in glioma risk, future research can begin to shift focus to what the underlying biologic mechanism behind this association may be, which could, in turn, yield new opportunities for immunotherapy or cancer prevention.

Inverse Association between Prediagnostic IgE Levels and the Risk of Brain Tumors: A Systematic Review and Meta-Analysis

An inverse association between allergic conditions and glioma risk has been suggested in many epidemiological studies. However, the evidence is inadequate to draw robust conclusions for the association between prediagnostic IgE levels and brain tumors risk. The aim of this study was to provide more precise estimates for this association by meta-analysis of all published studies. Overall, 8 individual studies with 2,461 cases and 3,934 controls were included in our study. A decreased risk of brain tumors (RR = 0.73, 95% CI 0.61–0.86, P < 0.001) was observed in relation to elevated level of total IgE. The negative association was significant between elevated total IgE level and the risk of glioma (RR = 0.74, 95% CI 0.62–0.88, P = 0.001). However, no significant relationship was demonstrated between testing positive for respiratory allergen-specific IgE and brain tumors risk. In addition, the role of prediagnostic IgE levels in brain tumors risk did not alter in men and women. The present study suggests that increased level of total prediagnostic IgE but not respiratory allergen-specific IgE plays a protective role in brain tumors risk, glioma in particular. More studies are warranted for further elucidation of the meningioma risk related to prediagnostic IgE levels.

Genetic Variations of Kinase Inserts Domain Receptor (KDR) Gene Are Associated with the Risk of Astrocytomas

Astrocytomas is one of the most common central nervous system (CNS) tumors with high mortality rate. Kinase insert domain receptor (KDR) is involved in the regulation of tumor angiogenesis, migration, and vascular permeability. The aim of the study was to explore the relationship between KDR polymorphisms and risk of astrocytomas. Blood samples were collected from 157 astrocytomas patients and 160 healthy controls. Three tag-SNPs (rs2071559C/T, rs2305948T/C, and rs1870377A/T) were identified from the International HapMap Project Databases and genotyped using the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). We evaluated the astrocytomas risk caused by individual SNPs and haplotype using odds ratios (ORs) and their 95 % confidence intervals (CIs). In the overall individual SNP analysis, the C allele of rs2071559 was correlated with an increased risk of astrocytomas. However, individuals with mutant allele A and genotype TA + AA of rs1870377 showed a protective effect against astrocytomas. Subgroup analysis based on WHO tumor grade revealed that the C allele of rs2071559 had more influence with the risk of astrocytomas in the grade III-IV (OR = 1.91) subgroup than the grade I-II (OR = 1.47) group. Genotype TT of rs2305948 was found to be significantly associated with susceptibility of astrocytomas only in the grade III-IV subgroup. The protective effect of rs1870377 did not reveal significant difference between the grade III-IV and grade I-II subgroups. Meanwhile, stratified analysis demonstrated that mutation of rs2071559 and rs2305948 could elevate the risk of astrocytomas more significantly in the subgroup of smokers than the nonsmokers. Interestingly, the protective effect of rs1870377 was more obvious in the nonsmokers than the smokers. Additionally, haplotype-specific analysis showed that haplotype CCT and CTT were related with an increased risk of astrocytomas. We found that individual with variants of rs2071559*C and rs2305948*T might significantly elevate the risk of astrocytomas, while mutants of rs1870377*A was associated with the decreased risk of astrocytomas. Further studies about ethnically diverse populations with larger sample size should be performed to confirm the correlation between KDR gene polymorphisms and risk of astrocytomas.

History of allergy and atopic dermatitis in relation to squamous cell and Basal cell carcinoma of the skin

BACKGROUND

Little is known about whether history of allergies and atopy is related to the occurrence of keratinocyte cancers. Thus, we evaluated the association between history of allergies and atopy and the incidence of squamous cell carcinoma (SCC) and early onset basal cell carcinoma (BCC).

METHODS

As part of a population-based case-control study, interviews were conducted with 1,050 residents of New Hampshire (375 early onset BCC cases and 251 controls, 254 SCC cases and 432 controls). ORs of SCC and early onset BCC and history of allergy and atopic dermatitis were computed using logistic regression, while controlling for potential confounding factors.

RESULTS

An overall inverse association was observed between a history of allergy and early onset BCC [OR, 0.61; 95% confidence interval (CI), 0.38-0.97] but not SCC (OR, 1.18; 95% CI, 0.78-1.79). Among women, we found reduced ORs of both early onset BCC and of SCC in relation to allergy history (early onset BCC OR, 0.53; 95% CI, 0.31-0.92 and SCC OR, 0.59; 95% CI, 0.29-1.19). Among men, we observed no clear association with early onset BCC (OR, 0.87; 95% CI, 0.39-1.99) and an increased risk of SCC (OR, 1.58; 95% CI, 0.93-2.69).

CONCLUSION

Our findings suggest that allergies and atopy may influence risk of early onset BCC and SCC, and that effects may be gender specific.

IMPACT

A deeper understanding of the immune mechanisms underlying allergies and atopy may provide new routes of preventing keratinocyte cancers.

Single Nucleotide Polymorphisms in IL-10, IL-12p40, and IL-13 Genes and Susceptibility to Glioma

Glioma is one of the most aggressive and most common tumors of the central nervous system (CNS) in humans. The exact causes of glioma are not well known, but evidence suggests the involvement of genetic factors in addition to environmental risk factors. The present study aimed to determine whether polymorphisms in IL-10-1082A/G, IL-12p40 1188C/A, and IL-13+2044G/A (rs20541) are associated with the incidence of glioma in Iraqi patients. Ninety-six patients with different grades of glioma and 40 apparently healthy individuals were recruited. A blood sample and genomic DNA were collected from all subjects. The amplification refractory mutation system and sequence-specific primer polymerase chain reaction (PCR) were used for genotyping of IL-10-1082A/G and IL-12p40 1188C/A, respectively; whereas, the IL-13+2044G/A was detected by DNA sequencing after amplification of the genes by PCR. All SNPs were within Hardy-Weinberg equilibrium and each appeared in three genotypes in patients and controls. In IL-10-1082A/G, these genotypes frequencies were AA (75%), AG (22.93%) and GG (2.07%) in patients as compared to similar frequencies (62.5%), (27.5%) and (10%) respectively, in controls. The variant IL-12p40 1188C/A genotype was AA (72.92%), AC (23.96%), and CC (3.13%%) in patients as compared to 65%, 30%, and 5%, respectively, in controls. The frequencies of IL-13+2044G/A genotypes (GG, GA, and AA) were 89.58%, 9.37%, and 1.04% among patients versus 47.5%, 32.5% and 20%, respectively, among controls. These results suggest a protective role of mutant alleles G and A in IL-10-1082A/G and IL-13+2044G/A against gliomas. Further studies with more rigorous parameter designs will be needed to confirm the current findings.

Eosinophil Infiltrates in Pilocytic Astrocytomas of Children and Young Adults

Objective

Eosinophils may affect each stage of tumour development. Many studies have suggested that tumour-associated tissue eosinophilia (TATE) is associated with favourable prognosis in some malignant tumours. However, only a few studies exist on TATE in central nervous system (CNS) tumours. Our recent study exhibited eosinophils in atypical teratoid/rhabdoid tumours (AT/RTs), pediatric malignant CNS tumours with divergent differentiation. This study examines eosinophils in pilocytic astrocytomas (PAs).

Methods

The study included 44 consecutive cases of patients with PAs and no concurrent CNS inflammatory disease.

Results

We found eosinophils in 19 (43%) of 44 PAs (patient age range, 0.5-72 years). Eosinophils were intratumoural and clearly distinguishable. The density of eosinophils was rare to focally scattered. PAs containing eosinophils were located throughout the CNS. Furthermore, eosinophilic infiltration was identified in 18 (62%) of 29 pediatric (age range, 0.5-18 years) PAs but only 1 (7%) of 15 (p<0.001, significantly less) adult (age range, 20-72 years) PAs. Eosinophilic infiltration showed no significant differences between PAs with and without MRI cystic formation, surgical procedures, or PAs with and without leptomeningeal infiltration. In comparison, eosinophils were absent in 10 pediatric (age range, 0.5-15 years) ependymomas (or anaplastic ependymomas).

Conclusions

These results suggest that eosinophils are common in pediatric PAs but rare in adult PAs. This difference is probably related to the developing immune system and different tumour-specific antigens in children. TATE may play a functional role in the development of pediatric PAs, as well as some other pediatric CNS tumours such as AT/RTs.

A prospective study of height and body mass index in childhood, birth weight, and risk of adult glioma over 40 years of follow-up

Greater attained height and greater body mass index (BMI; weight (kg)/height (m)(2)) in young adulthood have been associated with glioma risk, but few studies have investigated the association with body size at birth or during childhood, when the brain undergoes rapid cell growth and differentiation. The Copenhagen School Health Records Register includes data on 320,425 Danish schoolchildren born between 1930 and 1989, with height and weight measurements from ages 7-13 years and parentally recorded birth weights. We prospectively evaluated associations between childhood height and BMI, birth weight, and adult glioma risk. During follow-up (1968-2010), 355 men and 253 women aged ≥18 years were diagnosed with glioma. In boys, height at each age between 7 and 13 years was positively associated with glioma risk; hazard ratios per standard-deviation score at ages 7 (approximately 5.1 cm) and 13 (approximately 7.6 cm) years were 1.17 (95% confidence interval (CI): 1.05, 1.30) and 1.21 (95% CI: 1.09, 1.35), respectively. No associations were observed for childhood height in girls or for BMI. Birth weight was positively associated with risk (per 0.5 kg: hazard ratio = 1.13, 95% CI: 1.04, 1.24). These results suggest that exposures associated with higher birth weight and, in boys, greater height during childhood may contribute to the etiology of adult glioma.

Increased rate of positive penicillin skin tests among patients with glioma: insights into the association between allergies and glioma risk

OBJECT

Allergy and immunoglobulin E levels are inversely associated with glioma risk. Previous studies have focused on respiratory and food allergies, and little information is available regarding drug allergies. This study evaluated the rate of positive penicillin skin tests (PenSTs) and blood eosinophil counts in a large population of patients with glioma compared with nontumor controls to provide evidence for the relationship between drug allergies and glioma risk.

METHODS

A retrospective case-control study was conducted in patients diagnosed with glioma (n = 913) between January 2004 and June 2013. The study patients were matched with nontumor controls (n = 1091) for age, sex, and date of admission to the hospital. Preoperative results of the PenST and eosinophil counts were obtained, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using conditional logistic regression models, while a Kaplan-Meier analysis was used to assess overall survival.

RESULTS

The percentage of positive PenSTs was higher among patients with glioma than in control subjects. The age-, sex-, and admission date-adjusted OR for positive versus negative PenSTs was 2.392 (95% CI 1.891-3.026). Eosinophil counts were also higher in glioma cases than in controls: the OR for eosinophil > 0.06 × 10(9)/L versus ≤ 0.06 × 10(9)/L was 1.923 (95% CI 1.608-2.301). There was no association between positive PenST/eosinophil counts and glioma grade or patient survival (n = 105).

CONCLUSIONS

In contrast to previously reported relationships between allergy and glioma, in the present study a significantly higher rate of positive PenSTs and higher eosinophil counts were found in patients with glioma than in nontumor controls. These results suggest a complex relationship between allergies and glioma development.

Adult pilocytic astrocytomas: clinical features and molecular analysis

BACKGROUND

Adult pilocytic astrocytomas (PAs) are rare and have an aggressive clinical course compared with pediatric patients. Constitutive Ras/RAF/MAPK signaling appears to be an important oncogenic event in sporadic PA. We evaluated clinical data and molecular profiles of adult PAs at our institution.

METHODS

We identified 127 adult PAs in our institutional database. Cases with available tissue were tested for BRAF-KIAA1549 fusion/duplication (B-K fusion) by fluorescence in situ hybridization and submitted for mutation profiling using the Sequenom mutation profiling panel. Subgroup analyses were performed based on clinical and molecular data.

RESULTS

The majority of adult PAs are supratentorial. Twenty-two percent of cases had an initial pathologic diagnosis discordant with the diagnosis made at our institution. Recurrence was seen in 42% of cases, and 13% of patients died during follow-up. Adjuvant radiotherapy following surgical resection was associated with a statistically significant decrease in progression-free survival (P = .004). B-K fusion was identified in 20% (9 of 45) of patients but was not associated with outcome. No BRAF V600E mutations (0 of 40 tested) were found.

CONCLUSION

This was the largest single institution series of adult PA. A significant proportion of adult PAs follow an aggressive clinical course. Our results support a period of observation following biopsy or surgical resection. B-K fusion in adult PA does not influence outcome, and BRAF V600E mutation appears to be a very rare event. Further study of tumor biology and optimal treatment is needed, given a more aggressive clinical behavior.

Serum immunoglobulin e and risk of pancreatic cancer in the prostate, lung, colorectal, and ovarian cancer screening trial

Epidemiologic studies have consistently found that self-reported allergies are associated with reduced risk of pancreatic cancer. Our aim was to prospectively assess the relationship between serum immunoglobulin E (IgE), a marker of allergy, and risk. This nested case-control study within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) included subjects enrolled in 1994 to 2001 and followed through 2010. There were 283 cases of pancreatic cancer and 544 controls matched on age, gender, race, and calendar date of blood draw. Using the ImmunoCAP system, we measured total IgE (normal, borderline, elevated), IgE to respiratory allergens, and IgE to food allergens (negative or positive) in serum collected at baseline. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. We assessed interactions with age, gender, smoking, body mass index, and time between randomization and case diagnosis. Overall, there was no association between the IgE measures and risk. We found a statistically significant interaction by baseline age: in those aged ≥65 years, elevated risks were observed for borderline total IgE (OR, 1.43; 95% CI, 0.88-2.32) and elevated total IgE (OR, 1.98; 95% CI, 1.16-3.37) and positive IgE to food allergens (OR, 2.83; 95% CI, 1.29-6.20); among participants <65 years, ORs were <1. Other interactions were not statistically significant. The reduced risk of pancreatic cancer associated with self-reported allergies is not reflected in serum IgE.

Tim-3 on peripheral CD4⁺ and CD8⁺ T cells is involved in the development of glioma

Tim-3 acts as a negative regulatory molecule and plays a critical role in immune tolerance. The purpose of this study was to investigate the expression of Tim-3 on peripheral CD4⁺ and CD8⁺ T cells in glioma. A total of 30 newly diagnosed glioma patients and 30 healthy controls were recruited and leukocytes from peripheral blood mononuclear cells were analyzed for Tim-3 surface expression by flow cytometry. Plasma tumor necrosis factor-alpha (TNF-α) was also measured. Data showed that expression of Tim-3 was significantly increased in both CD4⁺ and CD8⁺ T cells in glioma patients than in controls (p<0.001 and p<0.001, respectively). Patients with a higher tumor grade revealed further elevated Tim-3 expression in CD8⁺ T cells compared with those with a lower tumor grade. Also, the Karnofsky score of patients was negatively correlated with the percentage of Tim-3⁺CD8⁺ T cells in glioma patients (p=0.007). In addition, an inverse correlation was observed between the plasma level of TNF-α and Tim-3⁺CD4⁺ T cells (p=0.005) or Tim-3⁺CD8⁺ T cells (p<0.001) in glioma patients. Our results suggested that Tim-3 may be involved in the development of glioma.

Interaction of allergy history and antibodies to specific varicella-zoster virus proteins on glioma risk

Glioma is the most common cancer of the central nervous system but with few confirmed risk factors. It has been inversely associated with chicken pox, shingles and seroreactivity to varicella virus (VZV), as well as to allergies and allergy-associated IgE. The role of antibody reactivity against individual VZV antigens has not been assessed. Ten VZV-related proteins, selected for high immunogenicity or known function, were synthesized and used as targets for antibody measurements in the sera of 143 glioma cases and 131 healthy controls selected from the San Francisco Bay Area Adult Glioma Study. Glioma cases exhibited significantly reduced seroreactivity compared to controls for six antigens, including proteins IE63 [odds ratio (OR) = 0.26, 95% confidence interval (CI): 0.12-0.58, comparing lowest quartile to highest) and the VZV-unique protein ORF2p (OR = 0.44, 95% CI: 0.21-0.96, lowest quartile to highest). When stratifying the study population into those with low and high self-reported allergy history, VZV protein seroreactivity was only associated inversely with glioma among individuals self-reporting more than two allergies. The data provide insight into both allergy and VZV effects on glioma: strong anti-VZV reactions in highly allergic individuals are associated with reduced occurrence of glioma. This result suggests a role for specificity in the anti-VZV immunity in brain tumor suppression for both individual VZV antigens and in the fine-tuning of the immune response by allergy. Anti-VZV reactions may also be a biomarker of effective CNS immunosurveillance owing to the tropism of the virus.

RTEL1 and TERT polymorphisms are associated with astrocytoma risk in the Chinese Han population

Common variants of multiple genes play a role in glioma onset. However, research related to astrocytoma, the most common primary brain neoplasm, is rare. In this study, we chose 21 tagging SNPs (tSNPs), previously reported to be associated with glioma risk in a Chinese case-control study from Xi'an, China, and identified their contributions to astrocytoma susceptibility. We found an association with astrocytoma susceptibility for two tSNPs (rs6010620 and rs2853676) in two different genes: regulator of telomere elongation helicase 1 (RTEL1) and telomerase reverse transcriptase (TERT), respectively. We confirmed our results using recessive, dominant, and additive models. In the recessive model, we found two tSNPs (rs2297440 and rs6010620) associated with increased astrocytoma risk. In the dominant model, we found that rs2853676 was associated with increased astrocytoma risk. In the additive model, all three tSNPs (rs2297440, rs2853676, and rs6010620) were associated with increased astrocytoma risk. Our results demonstrate, for the first time, the potential roles of RTEL1 and TERT in astrocytoma development.

Lysyl oxidase genetic variants and the prognosis of glioma

Lysyl oxidase (LOX) is a copper-dependent amine oxidase that plays important roles in the development and homeostasis of primary brain tumors such as glioma. The aim of this study was to investigate whether polymorphisms in the LOX gene were associated with susceptibility to glioma. We tested two functional polymorphisms of LOX, -22G/C and 473G/A, and compared them between 466 glioma cases and 502 healthy controls in the Chinese population. Results showed that the prevalence of 473AA genotype was significantly increased in cases than in controls (p = 0.001). Individuals who carried 473A allele had a 1.44-fold of increased risk for glioma than those with 473G allele (p = 0.002). In addition, when analyzing the survival time of glioma patients with LOX 473G/A polymorphism, cases with AA genotype had significantly shorter survival time compared to the patients carrying G allele (25.0 months vs 43.0 months, p = 0.0009). These results suggested that polymorphism in LOX gene was associated with increased susceptibility to glioma and could be used as prognostic factor for this malignancy.

Allergy and brain tumors in the INTERPHONE study: pooled results from Australia, Canada, France, Israel, and New Zealand

PURPOSE

A history of allergy has been inversely associated with several types of cancer although the evidence is not entirely consistent. We examined the association between allergy history and risk of glioma, meningioma, acoustic neuroma, and parotid gland tumors using data on a large number of cases and controls from five INTERPHONE study countries (Australia, Canada, France, Israel, New Zealand), to better understand potential sources of bias in brain tumor case-control studies and to examine associations between allergy and tumor sites where few studies exist.

METHODS

A total of 793 glioma, 832 meningioma, 394 acoustic neuroma, and 84 parotid gland tumor cases were analyzed with 2,520 controls recruited during 2000-2004. Conditional logistic regression models were used to obtain odds ratios (ORs) and 95 % confidence intervals (CIs) for associations between self-reported allergy and tumor risk.

RESULTS

A significant inverse association was observed between a history of any allergy and glioma (OR = 0.73, 95 % CI 0.60-0.88), meningioma (OR = 0.77, 95 % CI 0.63-0.93), and acoustic neuroma (OR = 0.64, 95 % CI 0.49-0.83). Inverse associations were also observed with specific allergic conditions. However, inverse associations with asthma and hay fever strengthened with increasing age of allergy onset and weakened with longer time since onset. No overall association was observed for parotid gland tumors (OR = 1.21, 95 % CI 0.73-2.02).

CONCLUSIONS

While allergy history might influence glioma, meningioma, and acoustic neuroma risk, the observed associations could be due to information or selection bias or reverse causality.

Anti-human-cytomegalovirus immunoglobulin G levels in glioma risk and prognosis

The role of human cytomegalovirus (HCMV) in glioma development and progression remains controversial. The purpose of our study was to assess the potential associations between anti-HCMV antibodies (immunoglobulin G [IgG] and immunoglobulin M [IgM]) and glioma risk and prognosis using data from the Harris County Case–Control Study. Multivariable logistic regression models were utilized to estimate odds ratios and 95% confidence intervals (CI) for the associations between glioma status and antibody levels among glioma cases (n = 362) and cancer-free controls (n = 462). Hazard ratios and 95% CIs were calculated using Cox proportional hazards regression, adjusting for age, race, and sex, to determine if antibody levels were associated with survival over time among cases. Among IgG-positive participants, increasing anti-HCMV IgG levels were associated with decreasing glioma risk (P for trend = 0.0008), and those with the lowest level of anti-HCMV IgG (<10 U/mL) had the highest glioma risk, controlling for age, sex, and race/ethnicity (OR: 2.51, 95% CI: 1.42–4.43). Antibody levels were not associated with survival among glioma cases. Our study contributes new evidence toward the potential importance of the direct and indirect effects of HCMV infection in gliomagenesis.

IgE and chemotherapy

The nexus of chemotherapeutic intervention and the immunomodulation of IgE-related phenomena are not well understood. The relationship bears importance in better understanding the causal and/or resultant effects of one on the other and their collective role in the management and sequelae of the cancer patient. This review discusses the relationship of chemotherapy on immunoglobulins with a focus on IgE and other related biological processes including hypersensitivity reactions and proposes models toward effective management of the cancer patient in this regard.

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.

Asthma and risk of brain cancer in children

PURPOSE

Little is known about the causes of central nervous system tumors in children. An inverse association between asthma and brain cancer was found in adults, but there is a dearth of studies in children. The goal of this study was to evaluate the association between asthma and brain cancer in children.

METHODS

Two hundred and seventy-two cases of children with brain tumor diagnosed between 0 and 14 years of age in the Province of Québec, Canada, between 1980 and 1999 and 272 incidence density-matched controls were included in the study. The parents of cases and controls were interviewed by phone using structured questionnaires. Besides asthma in children, family history of asthma, the presence of other atopies, and medication intake were also investigated. Conditional logistic regression was used to analyze the data.

RESULTS

Brain tumor risk was decreased in children with asthma (OR, 0.55; CI 95%, 0.33-0.93), with eczema (OR, 0.52; CI 95%, 0.17-1.57), and with both asthma and eczema (OR, 0.76; CI 95%, 0.18-3.2). Maternal or sibling asthma did not modify the effect of asthma on central nervous system (CNS) tumors, while father's asthma seemed to increase the risk, but numbers were small. Antiasthma medications such as inhaled corticosteroid and beta agonists seemed to increase the risk of CNS tumors (OR for steroids, 2.55; CI 95%, 0.79-8.20 and OR for inhaled beta agonist, 1.62; CI 95%, 0.57-4.63).

CONCLUSIONS

This study strengthens the hypothesis of inverse association between asthma and brain cancer in children, but family history and medications for asthma need further investigation.

Eosinophils in glioblastoma biology

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. The development of this malignant glial lesion involves a multi-faceted process that results in a loss of genetic or epigenetic gene control, un-regulated cell growth, and immune tolerance. Of interest, atopic diseases are characterized by a lack of immune tolerance and are inversely associated with glioma risk. One cell type that is an established effector cell in the pathobiology of atopic disease is the eosinophil. In response to various stimuli, the eosinophil is able to produce cytotoxic granules, neuromediators, and pro-inflammatory cytokines as well as pro-fibrotic and angiogenic factors involved in pathogen clearance and tissue remodeling and repair. These various biological properties reveal that the eosinophil is a key immunoregulatory cell capable of influencing the activity of both innate and adaptive immune responses. Of central importance to this report is the observation that eosinophil migration to the brain occurs in response to traumatic brain injury and following certain immunotherapeutic treatments for GBM. Although eosinophils have been identified in various central nervous system pathologies, and are known to operate in wound/repair and tumorstatic models, the potential roles of eosinophils in GBM development and the tumor immunological response are only beginning to be recognized and are therefore the subject of the present review.

Arlm1 is a male-specific modifier of astrocytoma resistance on mouse Chr 12

While many cancers show a sex bias, the genetic basis and molecular mechanisms underlying sex bias are not always clear. Astrocytoma and glioblastoma show male predominance in humans. We have shown previously that glial tumors forming in the Nf1-/+; Trp53-/+cis (NPcis) mouse model also show a sex bias in some genetic contexts. Using cross-species comparisons we have identified candidate male-specific modifiers of astrocytoma/glioblastoma. Linkage analysis of B6X(B6X129)-NPcis mice identifies a modifier of astrocytoma resistance specific to males, named Arlm1, on distal mouse Chr 12. Arlm1 is syntenic to human Chr 7p15, 7p21, 7q36, and 14q32 regions that are altered in human glioblastoma. A subset of these genes shows male-specific correlations to glioblastoma patient survival time and represents strong candidates for the Arlm1 modifier gene. Identification of male-specific modifier genes will lead to a better understanding of the molecular basis of male predominance in astrocytoma and glioblastoma.

Hunting for the causes of meningioma--obesity is a suspect

In this issue of the journal, Michaud and colleagues report a 48% increased risk of meningioma in obese individuals compared with individuals with a normal body mass index (BMI). This large prospective cohort study adds weight to the suggested link between BMI and meningioma, thus contributing to the growing number of cancer sites likely associated with body fatness. Although the exact mechanisms underlying the BMI-meningioma link are unclear, possible mediators include hormonal factors, immunologic response, and levels of insulin or insulin-like growth factors, each of which has been implicated by various levels of evidence in meningioma risk. Understanding the relationships between body fatness, height, and hormonal and immunologic factors could provide important clues to the etiology of meningioma and may have implications for the early detection and prevention of these tumors.

Lower incidence of biliary carcinoma in patients with primary sclerosing cholangitis and high serum levels of immunoglobulin E

BACKGROUND & AIMS

High serum levels of immunoglobulin (Ig)E often are detected in patients with primary sclerosing cholangitis (PSC), but the clinical significance is not known.

METHODS

We analyzed data from 44 patients with PSC and known serum levels of IgE. They were divided into groups called high IgE (>170 IU/mL; n = 17) or normal IgE (n = 27). We compared occurrence of biliary carcinoma including cholangiocellular and gallbladder carcinoma, liver transplantation, and death between groups.

RESULTS

The high IgE group had a later age of onset of PSC than the normal IgE group (54 ± 20 y vs 39 ± 16 y; P = .010); they also had a higher serum level of IgG (2078 ± 638 vs 1517 ± 475 mg/dL; P = .002) and IgG4 (104 ± 102 vs 38 ± 16 mg/dL; P = .002). Association with inflammatory bowel disease did not differ significantly between groups (5 of 17 vs 11 of 27; P = .661). No patient had biliary carcinoma in the high IgE group, but biliary carcinoma was observed during the follow-up period in 8 patients in the normal IgE group (0 of 17 vs 8 of 27; P = .016). The occurrence of biliary carcinoma, liver transplantation, or death did not differ between groups (4 of 17 vs 13 of 27; P = .124).

CONCLUSIONS

High serum levels of IgE often are observed in older patients with PSC and are associated with a reduced incidence of biliary carcinoma.

Primary brain tumours and specific serum immunoglobulin E: a case-control study nested in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Case-control studies suggest that patients with allergic diseases have a lower risk of developing glioma but not meningioma or schwannoma. However, those data can be differentially biased. Prospective studies with objective measurements of immunologic biomarkers, like immunoglobulin E (IgE), in blood obtained before cancer diagnosis could help to clarify whether an aetiological association exists.

METHODS

The present case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) measured specific serum IgE as a biomarker for the most common inhalant allergens in 275 glioma, 175 meningioma and 49 schwannoma cases and 963 matched controls using the ImmunoCAP specific IgE test. Subjects with an IgE level ≥0.35 kUA/l (kilo antibody units per litre) were classified as sensitized by allergens. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by adjusted conditional logistic regression models for each tumour subtype. The effect of dose-response relationship was assessed in five increasing IgE level categories to estimate P-values for trend.

RESULTS

The risk of glioma was inversely related to allergic sensitization (OR = 0.73; 95% CI 0.51-1.06), especially pronounced in women (OR = 0.53; 95% CI 0.30-0.95). In dose-response analyses, for high-grade glioma, the lowest OR was observed in sera with the highest IgE levels (P for trend = 0.04). No association was seen for meningioma and schwannoma.

CONCLUSION

The results, based on serum samples prospectively collected in a cohort study, provide some support for the hypothesis that individuals with allergic sensitization are at reduced risk of glioma and confirm results from previous case-control studies.

Prediagnostic plasma IgE levels and risk of adult glioma in four prospective cohort studies

BACKGROUND

Increased levels of serum immunoglobulin E (IgE) because of allergies have been inversely associated with risk of glioma in observational studies. Despite consistency across studies examining history of allergies and glioma, questions remain as to whether those are causal associations. An inverse association between serum IgE and risk of glioma was reported in a large case-control study, but reverse causality and treatment effects remain potential explanations for those findings.

METHODS

We combined data from four prospective cohort studies and used a nested case-control design to examine the association between allergy and glioma. We included glioma case subjects who were confirmed from medical or pathology records or from death certificates, and with prediagnostic blood available. We matched three control subjects per case subject, and the final numbers for analyses were 169 case subjects and 520 control subjects. Total IgE, food allergen-specific IgE, and respiratory allergen-specific IgE levels were measured using a highly sensitive fluorescent assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression analysis. Stratified analyses were conducted by age and birth cohorts.

RESULTS

Borderline elevated total IgE levels (25-100 kU/L) showed a statistically significant inverse association with glioma (OR = 0.63, 95% CI = 0.42 to 0.93), but no association was noted between elevated IgE (>100 kU/L) and glioma (OR = 0.98, 95% CI = 0.61 to 1.56) compared with clinically normal IgE levels (<25 kU/L). The association between glioma and total IgE was consistent for both men and women. Non-statistically significant inverse associations were noted for elevated IgE levels among individuals born before year 1930 (OR = 0.67, 95% CI = 0.34 to 1.34) and when restricting analyses to highly fatal (deceased within 2 years of diagnosis) glioma case subjects (OR = 0.64, 95% CI = 0.34 to 1.19) compared with individuals with clinically normal IgE levels. No associations were observed for either food allergen-specific or respiratory allergen-specific IgE levels.

CONCLUSIONS

Overall, our prospective findings are consistent with recent retrospective studies and support an association between total IgE levels and glioma. However, this association requires further elucidation.

Risk of squamous cell carcinoma of the skin in relation to IgE: a nested case-control study

BACKGROUND

Individuals diagnosed with nonmelanoma skin cancer have a high risk of developing a second skin cancer diagnosis. We assessed whether a marker of immune function related to atopic allergy, IgE, was associated with diagnosis of subsequent squamous cell carcinoma (SCC) of the skin in patients with a previous skin cancer enrolled in a skin cancer prevention trial.

METHODS

One hundred twelve individuals who developed an SCC (cases) were compared with 227 controls who did not develop SCC over the same followup period, matched on age, sex, and study center. Total, respiratory, and food-specific IgE were measured in the baseline or year one (prior to diagnosis) sera samples for each subject.

RESULTS

IgE levels were higher in cases with SCC than controls (comparing the highest quartile with the lowest, OR(total IgE) = 1.44; 95% CI: 0.73-2.85; OR(respiratory IgE) = 2.43; 95% CI: 1.16-5.06; OR(food IgE) = 2.53; 95% CI: 1.19-5.35). The association between respiratory IgE and subsequent skin cancer was strongest among individuals with a tendency to sunburn (OR(respiratory IgE) = 3.82; 95% CI: 1.05-13.88) compared with those with a tendency to tan (OR(respiratory IgE) = 0.95; 95% CI: 0.20-4.76). Among 25 subjects with repeat IgE measurements taken over several years, IgE levels were remarkably stable (interclass coefficient = 0.90 for total IgE).

CONCLUSION

These results indicate that allergy or allergy-associated IgE may be indicative of an immune phenotype that enhances risk of SCC, possibly via immune-associate inflammatory mediators.

IMPACT

Our results indicate that controlling allergy and IgE levels may be a new avenue of skin cancer prevention in susceptible populations, and implicate immune mechanisms in skin carcinogenesis.