Douglas Wolf, Syngenta Crop Protection LLC

Gina Hilton, PETA International Science Consortium Ltd., Germany

The rodent cancer bioassay is a key element in the current standard approach for assessing human carcinogenic potential for agrochemicals as well as other industry sectors. The length of time, costs, resources, and numbers of animals needed to perform the bioassay have led to the development of alternative approaches to progress the modernization of carcinogenicity assessment away from lifetime rodent cancer bioassays. Decades of research have described the limitations of the rodent cancer bioassay for identifying human carcinogenicity hazard and risk. These limitations have led to several international initiatives to establish approaches that modernize carcinogenicity assessment. For example, alternative approaches that include weight of evidence–based assessment of in vitro, in silico, and short-term in vivo tests have the potential to substantially reduce animal use while still protecting public health and better determining human carcinogenic hazard and risk. Frameworks to evaluate alternative approaches for carcinogenicity assessment of agrochemicals were developed by the Rethinking Chronic Toxicity and Carcinogenicity Assessment for Agrochemicals Project. These frameworks are being addressed through the European Partnership for Alternative Approaches to Animal Testing. This context produced a recognition of the need to map international efforts in order to develop and adopt new approach methodologies for carcinogenicity assessment. These initiatives generally recognize that more mechanistic approaches provide more granularity, increase testing efficiency, and may be more biologically relevant for evaluating both hazard and risk of chemical carcinogenicity to humans. The application of a mechanistic understanding to support new approaches to carcinogenicity assessment will be valuable for regulatory decision-making. The proposed session will outline the landscape of ongoing activities related to modernizing carcinogenicity assessment, present case studies for how this would work, provide regulatory perspective and feedback on what is possible and the challenges that must be addressed, and offer a perspective regarding the feasibility of achieving a globally harmonized approach to carcinogenicity assessment without long-term bioassays. This session includes international perspectives from government, industry, and nongovernmental organizations to explore a modern paradigm for science-based carcinogenicity assessment. It is intended to stimulate discussion with Workshop attendees in order to gain feedback and help progress the roadmap to modernized agrochemical carcinogenicity assessment.