Allergy and Risk of Childhood Acute Lymphoblastic Leukemia: A Population-based and Record-based Study.
ABSTRACT A deficit of normal immune stimulation in early childhood is a suspected risk factor for both childhood acute lymphoblastic leukemia (ALL) and allergies. The present study utilized a population-based case-control design using medical claims data from the National Health Insurance Research Database of Taiwan to evaluate the association between allergy and childhood leukemia. Eight hundred forty-six childhood ALL patients who were newly diagnosed during 2000 to 2008 and were older than 1 but less than 10 years of age were individually matched with 3,374 controls based on sex, birth date, and time of diagnosis (reference date for the controls). Conditional logistic regression was performed to assess the association between childhood ALL and allergies. An increased risk of ALL was observed with having an allergy less than 1 year before the case's ALL diagnosis (odds ratio (OR) = 1.7, 95% confidence interval (CI): 1.5, 2.0), more than 1 year before the case's diagnosis (OR = 1.3, 95% CI: 1.1, 1.5), and before the age of 1 year (OR = 1.4, 95% CI: 1.1, 1.7). These results suggest that the pathogenesis of childhood ALL and allergy share a common biologic mechanism.
SourceAvailable from: Alessandro Allegra[Show abstract] [Hide abstract]
ABSTRACT: Increasing evidence indicates that a dysregulated immune system, as the one found in allergic disorders, can affect survival of tumor cells. A possible association between allergies and risk of hematologic malignancies has been examined in several epidemiological studies, however, results were not always consistent. The aim of this review is to report the preclinical and clinical data, which support a correlation between allergy and hematologic neoplasms. Immune system modulation could represent a powerful tool in the prevention and treatment of hematologic malignancies.Leukemia Research 10/2014; 38(10). DOI:10.1016/j.leukres.2014.08.004 · 2.69 Impact Factor
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ABSTRACT: Background: Allergic diseases signify immune dysregulation attributable to underlying genetics and environmental exposures. Associations between various allergies and hematopoietic cancers have been observed, albeit inconsistently, however few prospective studies have examined the risk, and even fewer among older adults. Methods: We examined risk of incident hematopoietic cancers in those reporting allergic diseases in a population-based cohort of 22,601 older women (Iowa Women's Health Study). Self-reported allergic status, including asthma, hay fever, eczema and/or other allergies, was determined via questionnaire in 1997 (mean age=72 years, range 63-81 years). Incident cancers were ascertained by linkage with the Iowa Cancer Registry from 1997-2011. Cox proportional hazards regression was performed to estimate multivariate-adjusted hazard ratios (HR) and 95% confidence intervals (CIs) for myeloid (N=177) and lymphoid (N=437) malignancies, respectively. Results: Allergic diseases were not associated with risk of myeloid (HR=1.00, 95% CI: 0.72-1.37) or lymphoid (HR=0.99, 95% CI: 0.81-1.22) malignancies overall, or for most allergic and malignant subtypes examined. Self-reported asthma was positively associated with development of myelodysplastic syndrome (MDS, HR=2.00, 95% CI: 0.93-4.32). In addition, there was a 30-40% decrease in risk of both lymphoid and myeloid cancers in those reporting rural residences but no association in those reporting urban residences; the interaction between residence and allergy was statistically significant for lymphoid malignancies (Pinteraction=0.05). Conclusions and Impact: These results suggest asthma may contribute to the pathogenesis of MDS, a finding consistent with the chronic antigen stimulation hypothesis. Susceptibility differences by location of residence are concordant with the hygiene hypothesis and merit additional exploration.Cancer Epidemiology Biomarkers & Prevention 06/2014; 23(9). DOI:10.1158/1055-9965.EPI-14-0423 · 4.32 Impact Factor
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ABSTRACT: Down syndrome (DS) is a common congenital anomaly, and children with DS have a substantially higher risk of leukemia. Although understanding of genetic and epigenetic changes of childhood leukemia has improved, the causes of childhood leukemia and the potential role of environmental exposures in leukemogenesis remain largely unknown. Although many epidemiologic studies have examined a variety of environmental exposures, ionizing radiation remains the only generally accepted environmental risk factor for childhood leukemia. Among suspected risk factors, infections, exposure to pesticides, and extremely low frequency magnetic fields are notable. While there are well-defined differences between leukemia in children with and without DS, studies of risk factors for leukemia among DS children are generally consistent with trends seen among non-DS (NDS) children. We provide background on DS epidemiology and review the similarities and differences in biological and epidemiologic features of leukemia in children with and without DS. We propose that both acute lymphoblastic and acute myeloblastic leukemia among DS children can serve as an informative model for development of childhood leukemia. Further, the high rates of leukemia among DS children make it possible to study this disease using a cohort approach, a powerful method that is unfeasible in the general population due to the rarity of childhood leukemia.Cancer Epidemiology 10/2014; DOI:10.1016/j.canep.2014.07.006 · 2.56 Impact Factor