In an experiment consisting of the continuous constant application of various carcinogenic regimens to a pure strain of experimental animals for a long period, the cancer incidence rates so caused may be studied and compared by the fit of an appropriate class of statistical distributions. In this paper we show that a Weibull distribution in which the age-specific cancer incidence rate rises as a power of time since first risk is more appropriate than a lognormal distribution. If the Weibull family of distributions is used, more information can be extracted from the data, and differences of toxicity between various regimens will not bias the comparison of their carcinogenic forces.

Type

Journal article

Journal

Br J Cancer

Publication Date

08/1972

Volume

26

Pages

258 - 261

Keywords

Animals, Biological Assay, Carcinogens, Methods, Models, Biological, Statistics as Topic