title: Birth order, allergies and lymphoma risk: results of the European collaborative research project Epilymph.
abstract: Lymphomas are a heterogeneous group of malignancies of the immune system. Recent studies suggest that immunological conditions which are modulated by lifestyle-dependent environmental determinants might affect lymphoma risk. We used data from Epilymph, a European multi-centric case-control study with 2,480 cases and 2,540 controls, to analyse the relationship between lifestyle-dependent immunological determinants and risk of lymphomas. We found an inverse relationship between risk of lymphoma and allergies, mainly respiratory (OR=0.86, CI=0.89-1.01) and food allergies (OR=0.67, CI=0.52-0.85), a slightly elevated lymphoma risk for first-born children (OR=1.17, CI=0.99-1.39) and only children (OR=1.10, CI=0.86-1.39). The inverse relationship between atopic disorders and risk of lymphomas is consistent with earlier observations. Our findings on birth order and lymphoma increase the inconsistency of findings across studies and suggest a critical reappraisal of potential underlying mechanisms.
authors.affiliation: Division of Cancer Epidemiology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany. n.becker@dkfz.de
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Becker
authors.forename: Silvia
authors.initials: S
authors.lastname: de Sanjose
authors.forename: Alexandra
authors.initials: A
authors.lastname: Nieters
authors.forename: Marc
authors.initials: M
authors.lastname: Maynadié
authors.forename: Lenka
authors.initials: L
authors.lastname: Foretova
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Cocco
authors.forename: Anthony
authors.initials: A
authors.lastname: Staines
authors.forename: Tomas
authors.initials: T
authors.lastname: Alvaro
authors.forename: Martine
authors.initials: M
authors.lastname: Vornanen
authors.forename: Paul
authors.initials: P
authors.lastname: Brennan
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
mesh_terms: D000328:Adult; D000368:Aged; D001722:Birth Order; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology; D008223:Lymphoma / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors