ANIMAL CARCINOGENICITY EXPERIMENTS WITH AND WITHOUT SERIAL SACRIFICE

Commonly used tests to detect carcinogenic potential of a test compound make extreme assumptions about the lethality of tumors, due to their occult nature. In this paper we compare a nonparametric test, which uses interim sacrifice to avoid such assumptions, with these tests using simulation based on the ED01 data. Results indicate that in the presence of a significant difference in the mortality rate with treatment, commonly used methods could fail to maintain the nominal significance level. However, when there is no difference in the mortality rate, such procedures are robust to the underlying assumptions about the lethality of tumors and more powerful than the nonparametric test using interim sacrifice.