Re-analysis of 2,4-D use and the occurrence of canine malignant lymphoma
Kaneene, J.B.; Miller, R.
Veterinary and Human Toxicology 41(3): 164-170
1999
ISSN/ISBN: 0145-6296 PMID: 10349709 Document Number: 508715
An independent scientific review panel had concerns involving study design, analysis and interpretation of results in a case-control study investigating the relationship between canine malignant lymphoma (CML) and the use of 2,4-D herbicide (Journal of the National Cancer Institute (1991) 83, 1226). To address these concerns, a re-analysis was done to examine 2,4-D use and its association with CML. This case-control study re-analysed the data using the exposure definition used in the original study, re-analysed the data using a redefinition of exposure, and conducted a dose-response analysis with the redefined exposure criteria. The redefined exposure criteria included the average frequency of canine access to treated lawns within 3 days of application and how often the dog was exposed to gardening chemicals as alternative measures of dosage. The results agreed with the original authors' analyses that no effects were found when stratifying by survey method and geographic region, and that there were no significant differences between separated and pooled control groups. However, the re-analyses did not confirm a dose-response relationship between 2,4-D use and CML and the occurrence of CML was not found significantly associated with the use of 2,4-D.