Title
Towards a mechanism-based approach for the prediction of nongenotoxic carcinogenic potential of agrochemicals
Author
Heusinkveld, H.
Braakhuis, H.
Gommans, R.
Botham, P.
Corvaro, M.
van der Laan, J.W.
Lewis, D.
Madia, F.
Manou, I.
Schorsch, F.
Wolterink, G.
Woutersen, R.
Corvi, R.
Mehta, J.
Luijten, M.
Publication year
2020
Abstract
Chemical substances are subjected to assessment of genotoxic and carcinogenic effects before being marketed to protect man and the environment from health risks. For agrochemicals, the long-term rodent carcinogenicity study is currently required from a regulatory perspective. Although it is the current mainstay for the detection of nongenotoxic carcinogens, carcinogenicity studies are shown to have prominent weaknesses and are subject to ethical and scientific debate. A transition toward a mechanism-based weight-of-evidence approach is considered a requirement to enhance the prediction of carcinogenic potential for environmental (agro)chemicals. The resulting approach should make optimal use of innovative (computational) tools and be less animal demanding. To identify the various mode of actions (MOAs) underlying the nongenotoxic carcinogenic potential of agrochemicals, we conducted an extensive analysis of 411 unique agrochemicals that have been evaluated for carcinogenicity by the United States Environmental Protection Agency (US EPA) and the European Chemicals Agency (ECHA). About one-third of these substances could be categorized as nongenotoxic carcinogens with an average of approximately two tumor types per substance, observed in a variety of organs. For two-third of the tumor cases, an underlying MOA (network) could be identified. This analysis demonstrates that a limited set of MOA (networks) is underlying nongenotoxic carcinogenicity of agrochemicals, illustrating that the transition toward a MOA-driven approach appears manageable. Ultimately the approach should cover relevant MOAs and its associated key events; this will also facilitate the evaluation of the human relevance. This manuscript describes the results of the analysis while identifying knowledge gaps and necessities to achieve a mechanism-based weight-of-evidence approach.
Subject
Pesticides; carcinogenicity
Mode of action
Rodent
Cancer bioassay
Risk assessment
Weight-ofevidence
Hazard assessment
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http://resolver.tudelft.nl/uuid:e2cf40a3-0b46-4b9e-9a4c-9433fef9843c
DOI
https://doi.org/10.1080/10408444.2020.1841732
TNO identifier
884289
ISSN
1040-8444
Source
Critical Reviews in Toxicology, 50 (50), 725–739
Document type
article