American Journal of Epidemiology Advance Access originally published online on June 26, 2006
American Journal of Epidemiology 2006 164(4):367-375; doi:10.1093/aje/kwj208
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Original Contribution |
Occupational Exposure and Laryngeal and Hypopharyngeal Cancer Risk in Central and Eastern Europe
1 Cancer Research Centre, Moscow, Russia
2 International Agency for Research on Cancer, Lyon, France
3 Institute of Occupational Medicine, Lodz, Poland
4 Institute of Hygiene, Public Health, Health Services and Management, Bucharest, Romania
5 Specialized State Health Institute, Banská Bystrica, Slovakia
6 London School of Hygiene and Tropical Medicine, London, United Kingdom
Correspondence to Dr. Paul Brennan, Genetic Epidemiology Group, Genetics and Epidemiology Cluster, International Agency for Research on Cancer, 150 cours Albert Thomas, 69008 Lyon, France (e-mail: brennan{at}iarc.fr).
A multicenter case-control study was conducted during 1999–2002 in four European countries (Poland, Romania, Russia, and Slovakia) to evaluate the role of occupational exposures in risk of laryngeal/hypopharyngeal cancer. Male cancer cases (34 hypopharyngeal, 316 laryngeal) with full data on occupational history and nonoccupational factors were compared with 728 hospital controls for occupational exposure to 73 suspected carcinogens. Occupational history was evaluated by industrial hygienists blinded to case/control status. Elevated risks for ever exposure to coal dust were found for both hypopharyngeal (odds ratio (OR) = 4.19, 95% confidence interval (CI): 1.18, 14.89) and laryngeal (OR = 1.81, 95% CI: 0.94, 3.47) cancer, with clear dose-response patterns. Inclusion of a 20-year lag in the analysis strengthened these associations. Hypopharyngeal cancer risk was also significantly associated with exposure to mild steel dust (OR = 3.04, 95% CI: 1.39, 6.64) and iron compounds and fumes (OR = 2.74, 95% CI: 1.29, 5.84), without clear dose-response relations. Laryngeal cancer was significantly associated with exposure to hard-alloys dust (OR = 2.23, 95% CI: 1.08, 4.57) and chlorinated solvents (OR = 2.18, 95% CI: 1.03, 4.61), without dose-response relations. A possible link between high formaldehyde exposure and laryngeal cancer was suggested. No association was found for exposure to asbestos or inorganic acid mists. These data indicate that occupational exposure to coal dust may play a role in laryngeal and hypopharyngeal cancer. Other possible relations need further evaluation.
hypopharyngeal neoplasms; laryngeal neoplasms; occupational exposure
Abbreviations: CI, confidence interval; OR, odds ratio