Research Papers: Lung CancerRetinol supplementation and mesothelioma incidence in workers earlier exposed to blue asbestos (Crocidolite) at Wittenoom, Western AustraliaAlfonso, Helman S.a c; Reid, Alisona d; de Klerk, Nicholas H.a b; Olsen, Nolaa; Mina, Robina; Ambrosini, Gina L.a; Beilby, Johne; Berry, Geoffreyg; Musk, Bill A.W.a fAuthor Information aSchool of Population Health bDepartment of Biostatistics and Genetic Epidemiology, Telethon Institute for Child Health Research cWestern Australian Centre for Health and Ageing dCentre for Medical Research ePathWest Laboratory of Western Australia, Department of Molecular Genetics, QEII Medical Centre, Nedlands West Australia and School of Surgery and Pathology, University of Western Australia fDepartment of Respiratory Medicine, Sir Charles Gairdner Hospital, Nedlands, Perth, Western Australia gSchool of Public Health, University of Sydney, Sydney, New South Wales, Australia Correspondence to Dr Helman S. Alfonso, Universidad Western Australia, 48 Murray Street, Perth, Western Australia 6001, Australia Tel: +61 8 9224 3199; fax: +61 8 9224 2063; e-mail: email@example.com Received 9 February 2010 Accepted 26 April 2010 European Journal of Cancer Prevention: September 2010 - Volume 19 - Issue 5 - p 355-359 doi: 10.1097/CEJ.0b013e32833c1bcb Buy Metrics Abstract Owing to the high rates of malignant mesothelioma in workers exposed to crocidolite earlier at Wittenoom and evidence of protection against cancer by vitamin A, a population-based cancer prevention programme providing retinol supplements (25 000 IU/day) was commenced in 1990. The former workers at Wittenoom known to be alive and living in Western Australia in June 1990 constitute the study population. The participants were classified into two groups: those who received supplemental retinol (intervention group) and those who received none (comparison group). The relative rate of mesothelioma for those receiving retinol was estimated using Cox regression, adjusting for cumulative asbestos exposure and age at first exposure to asbestos. Nine hundred and twenty-eight former Wittenoom workers received retinol at some stage of the programme, whereas 1471 workers never received retinol (comparison group). Those who received retinol were younger, had a greater exposure to asbestos and smoked less than the comparison group. There were 65 cases of mesothelioma in the retinol group and 88 in the comparison group. After adjustment, the hazard ratio was 0.99 (95% confidence interval=0.70–1.41). This result did not alter when the participants who received only retinol once or those who received β-carotene earlier were excluded from the analysis. In conclusion, this study provides little support for possible preventive effects of retinol against mesothelioma in workers exposed to blue asbestos. © 2010 Lippincott Williams & Wilkins, Inc.