title: Asbestos exposure and histological subtype of malignant mesothelioma.
abstract: BACKGROUND
  Malignant mesothelioma (MM) has distinct histological subtypes (epithelioid, sarcomatoid and biphasic) with variable behaviour and prognoses. It is well recognised that survival time varies with the histological subtype of MM. It is not known, however, if asbestos exposure characteristics (type of asbestos, degree of exposure) are associated with different histological subtypes.
  
  
  OBJECTIVE
  To determine if the pathological MM subtype is associated with the type of asbestos or the attributes of asbestos exposure.
  
  
  METHODS
  Cases of MM for the period 1962 until 2012, their main histological subtype and their most significant source of asbestos exposure were collected from the Western Australian Mesothelioma Registry. Exposure characteristics included, degree of asbestos exposure (including total days exposed, years since first exposure and, for crocidolite only, calculated cumulative exposure), source of exposure (occupational or environmental), form of asbestos handled (raw or processed) and type of asbestos (crocidolite only or mixed fibres).
  
  
  RESULTS
  Patients with the biphasic subtype were more likely to have occupational exposure (OR 1.83, 1.12 to 2.85) and exposure to raw fibres (OR 1.58, 1.19 to 2.10). However, differences between subtypes in the proportions with these different exposure characteristics were small and unlikely to be biologically relevant. Other indicators of asbestos exposure were not associated with the histological subtype of mesothelioma.
  
  
  CONCLUSIONS
  There was no strong evidence of a consistent role of asbestos exposure indicators in determining the histological subtype of MM.
authors.affiliation: School of Population Health, University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Franklin
authors.affiliation: School of Public Health, Curtin University, Bentley, Western Australia, Australia.
authors.forename: H
authors.initials: H
authors.lastname: Alfonso
authors.affiliation: School of Public Health, Curtin University, Bentley, Western Australia, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Reid
authors.affiliation: School of Population Health, University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Olsen
authors.affiliation: PathWest, Queen Elizabeth II Medical Centre and University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: K B
authors.initials: KB
authors.lastname: Shilkin
authors.affiliation: School of Population Health, University of Western Australia, Nedlands, Western Australia, Australia Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.
authors.forename: F
authors.initials: F
authors.lastname: Brims
authors.affiliation: School of Population Health, University of Western Australia, Nedlands, Western Australia, Australia Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: N
authors.initials: N
authors.lastname: de Klerk
authors.affiliation: School of Population Health, University of Western Australia, Nedlands, Western Australia, Australia Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.
authors.forename: A W
authors.initials: AW
authors.lastname: Musk
mesh_terms: D000368:Aged; D001194:Asbestos; D017638:Asbestos, Crocidolite / Q000009:adverse effects; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000473:pathology*; D008297:Male; D008654:Mesothelioma / Q000139:chemically induced* / Q000473:pathology*; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D008906:Mining; D009784:Occupational Diseases / Q000139:chemically induced / Q000473:pathology; D016273:Occupational Exposure / Q000009:adverse effects*; D011379:Prognosis; D012042:Registries; D011795:Surveys and Questionnaires; D014904:Western Australia
chemical_list: D017638:Asbestos, Crocidolite; D001194:Asbestos
keywords: exposure