REFINEMENT AND ANIMAL WELFARE IN CANCER MODELS

Jann Hau

Department of Experimental Medicine, University and University Hospital of Copenhagen, Denmark

Laboratory animal models have been essential for understanding tumour biology, for development and testing of drug therapies, and for risk assessments of potential carcinogens. Animal models remain pivotal for studies of biological mechanisms involved in the development of cancer and for studies of tumours growing in vivo. Scientists have moral and legal obligations for the welfare of the animals in their care during experimentation, and proper consideration should always be given to the 'three R's' (replacement, reduction, and refinement). When animals are necessary to address a particular question in oncology, pain and distress must be minimised, and avoidable pain is unacceptable. Studies of experimentally induced neoplasia present particular problems, and scientists should make every effort for implementation of the earliest humane endpoints possible to minimise the adverse effects on the animals. Death as an endpoint should obviously no longer be accepted, and researchers should be encouraged to introduce the earliest possible endpoints and to disseminate the information by publishing improvements with respect to refinement and animal welfare score sheets in experimental protocols.

Continuous refinement of experimental protocols resulting in the introduction of the earliest achievable endpoints requires competence, commitment and collaboration of scientists and all staff associated with animal care and animal experimentation. All staff should understand their individual responsibilities, and an unambiguous chain of communication and accountability should be established. This allows immediate action to address animal welfare issues that may arise as a consequence of experimental protocols.