Abstract |
Long-term animal tests, particularly in laboratory rodents, are referred to as bioassays. The animal bioassay is still the most commonly employed method for detecting potential human chemical carcinogens. The use of the pathology data, particularly the tumor data, derived from these animal studies for carcinogen risk assessment, both qualitative and quantitative, is not without its problems. These problems could be substantially reduced if the mechanisms of tumor formation and progression were elucidated. Although more recent animal studies are incorporating methods for determining such mechanisms, the state of the authors present knowledge is such that assumptions as to these mechanisms is the accepted, not the preferred, method. Many of these problems, therefore, are not solvable until the appropriate mechanisms are clarified. At the present time, the best method appears to be the practical approach taken by many groups. |