title: [Determination of the effective number of animals to be used in oncologic experiments, and in testing for carcinogenicity, in particular].
abstract: An effective number of animals used in oncological experiments in general and carcinogenicity testing in particular is usually calculated as that of animals which have survived by the time a first tumor of any type (epithelial, mesenchymal, fatal, incidental etc.) is detected in any group, including control, throughout the whole experiment. This is justified for the determination of total number of tumors or the incidence of early tumors which are detected first. It is assumed that tumors of different histologies and in different organs, on the one hand, and early tumors, on the other, are detected at the same time. However, such approach may be misleading as far as tumors detected at later stages are concerned when the number of animals is much lower than that when the first rapidly-growing tumor was found. It seems advisable to compute effective numbers for all tumor patterns individually or for a given pattern in each organ. Hence, in either experimental situation, an effective number will refer to animals surviving till a first target tumor is detected.
authors.affiliation: N.N. Blokhin Center for Oncology Research, Russian Academy of Medical Sciences, Moscow.
authors.forename: V S
authors.initials: VS
authors.lastname: Turusov
mesh_terms: D002273:Carcinogens / Q000633:toxicity; D006801:Humans; D009369:Neoplasms / Q000139:chemically induced; D012106:Research / Q000592:standards*; D018401:Sample Size
chemical_list: D002273:Carcinogens