Variations in prevalence of endocrine tumors among different colonies of rats? A retrospective study in the Hannover registry data base.
Illustrated by data derived from the endocrine system it could be demonstrated that at least the following requirements have to be fulfilled when using historical control data for the interpretation of animal studies: The main and basic requirement is the utilization of standardized diagnostic criteria and a systematized nomenclature for all data which should be compared. This includes the historical control data as well as histopathological diagnoses obtained from other animal studies. All findings stored in the REGISTRY are based on standardized criteria and this nomenclature was also applied for the more recent studies which were evaluated by pathologists of the member companies. Data from literature which are frequently used for comparison and interpretation cannot always fulfill this requirement due to the variation of diagnostic criteria used by different investigators. The second important requirement is an exact knowledge of study-related details. Some dependencies of the tumor rate on the sex, the strain, the breeder and the age were shown in a few examples. But other parameters, like diet, caging, bedding etc. may also influence the frequency of spontaneously occurring tumors and therefore have to be taken into account. In the REGISTRY such data from routine carcinogenicity and toxicity studies are available because all these studies are performed under GLP conditions and all parameters are carefully recorded. During the relatively short period of its activity, the REGISTRY has become not only source of historical laboratory data, but also it subserves as indispensable tool of quality control warranted by peer-review effects of panel meetings. An additional benefit will emanate from the data base in the near future: Exact knowledge of the magnitude of the influence of distinct parameters will enable the member companies to use the information for the design or optimization of new studies, as well as to extend the analysis and support the interpretation of observed results.
Morawietz
G
G
Fraunhofer Institute of Toxicology and Aerosol Research, Hannover, Germany.
Rittinghausen
S
S
D000818:Animals; D000830:Animals, Laboratory; D016208:Databases, Factual / Q000592:standards; D004701:Endocrine Gland Neoplasms / Q000453:epidemiology / Q000662:veterinary*; D005260:Female; D008297:Male; D015995:Prevalence; D051381:Rats; D011919:Rats, Inbred Strains; D012042:Registries; D012189:Retrospective Studies; D012376:Rodent Diseases / Q000453:epidemiology*; D009626:Terminology as Topic