ABSTRACT
INTRODUCTION The greatest concern for pharmaceutical or chemical compounds is the drug-dependent development of tumors. This induction of cancers was from the beginning of the International Conferences onHarmonization (ICH) in the focus of the discussions of the participating experts. The objectives in the ICH Safety Expert Working Party were to improve the sensitivity of preclinical testing and provide better tools for a valid and early assessment of a tumorigenic potential without increasing the number of animals necessary for the evaluation. Accordingly, the ICH Expert Working Groups created guidelines for carcinogenicity testing (Table 1).
