An updated meta-analysis of formaldehyde exposure and upper respiratory tract cancers
Collins, J.J.; Acquavella, J.F.; Esmen, N.A.
Journal of Occupational and Environmental Medicine 39(7): 639-651
1997
ISSN/ISBN: 1076-2752 PMID: 9253725 Document Number: 478961
In this study, we summarize 47 epidemiologic studies related to formaldehyde exposure and use meta-analytic techniques to assess findings for cancers of the lung, nose/nasal sinuses, and nasapharynx. Our analyses indicate that workers with formaldehyde exposure have essentially null findings for lung cancer and a slight deficit of sinonasal cancer. Nasopharyngeal cancer rates were elevated moderately in a minority of studies. Most studies, however, did not find any nasopharyngeal cancers, and many failed to report their findings. After correcting for underreporting, we found a meta relative risk of 1.0 for cohort studies. Case-control studies had a meta relative risk of 1.3. Our review of the exposure literature indicated that the nasopharyngeal cancer case-control studies represented much lower and less certain exposures than the cohort studies. We conclude that the available studies do not support a causal relation between formaldehyde exposure and nasopharyngeal cancer. This conclusion conflicts with conclusions from two previous meta-analyses, primarily because of our consideration of unreported data.