Criteria for the evaluation of studies in transgenic models

The generation, evaluation, and presentation of data from the ILSI Alternatives to Carcinogenicity Testing (ACT) program was standardized to ensure that the results of studies performed in multiple laboratories could be reliably compared. To this end, standardized experimental protocols, tissue collection procedures, histopathology nomenclature, diagnoses, and terminology were employed by study participants. In the experimental phase, this approach provided important cross-model consistency. To ensure comparability in the data evaluation phase of the project, interpretive criteria were defined to allow the characterization of study outcome as positive, negative, or equivocal in regards to carcinogenic response. These criteria helped to provide consistency across models because separate Assay Working Groups were established to evaluate the results of each model. To organize and compile the data from the ILSI ACT program, a database has been developed and data entered in standardized format to facilitate cross- and intramodel comparisons. In summary, the early development of standardized test protocols, evaluation procedures, and interpretive criteria has resulted in a data set in which users can have a high level of assurance that results in the database reflect consistently applied experimental and interpretive guidelines.