Animal Models in Cancer Research: Assessment of Severity and the Application of Humane Endpoints

Refinement is one of the three foundations of the 3Rs concept, a concept that underpins good animal-based research. For ethical and legal reasons, the severity of a procedure or an experiment on the welfare and health of an experimental animal needs to be estimated before starting the experiment. This estimation needs to be done for two main reasons. First, any inherent negative effects that a procedure or an experiment has on an experimental animal can be minimized by establishing humane endpoints. Second, the severity of all procedures in a scientific experiment contributes to the cumulative suffering that an experimental animal will experience during its lifespan. The aim of this chapter is to explain refinement and humane endpoints and their use in reducing the severity and thereby assure the welfare of an experimental animal while it participates in a scientific investigation.