Mesothelioma in patients with nonoccupational asbestos exposure. An evidence-based approach to causation assessment.
The specific parameters of nonoccupational asbestos exposures (NOAE) that can distinguish an idiopathic from an asbestos-caused malignant mesothelioma (MM) are controversial. A systematic literature review yielded 1028 cases with this putative association. Only 287 of those reports had a defined single exposure to a household, building occupant, or neighborhood/community asbestos source. The available "evidence" was used to develop semiarbitrary evidence-based causation guideline rules for the assessment of putative associations between MM and NOAE. The rules are classified into class A (tissue burden analysis shows asbestos body counts or fiber counts in lung tissues comparable to MM caused by occupational exposure to asbestos) and classes B to D based on whether certain combinations of NOAE features and MM (evidence) have been described in over 15% (class B), 5% to 15% (class C), and less than 5% (class D) of the patients reviewed. The proposed 4 classes of evidence-based causation guidelines provide a semiarbitrary framework to evaluate the causation of individual MM patients by NOAE based on decreasing levels of currently available evidence. The neoplasms in classes A to C patients are probably caused by NOAE, with decreasing weight of evidence in the 3 groups. There is minimal evidence to support the causation of MM by NOAE in class D patients. There is no evidence or only anecdotal evidence to support a causal association between MM and NOAE in individuals who cannot be classified into any of the 4 classes. Future studies are needed to provide more comprehensive data regarding the association between MM and NOAE.
Marchevsky
Alberto M
AM
Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. marchevsky@cshs.org
Harber
Philip
P
Crawford
Lori
L
Wick
Mark R
MR
D001194:Asbestos / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity*; D004781:Environmental Exposure / Q000009:adverse effects*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D016239:MEDLINE; D008297:Male; D008654:Mesothelioma / Q000209:etiology* / Q000473:pathology; D010997:Pleural Neoplasms / Q000209:etiology* / Q000473:pathology; D014116:Toxicology
D002273:Carcinogens; D001194:Asbestos