Determination of carcinogenic synergism from the latent period

We present a method for determining the presence or absence of synergism between two carcinogens A and B from the latent period of tumors. The method is applied to data consisting of the means and standard deviations of the times at which tumors become palpable and at which death from tumor occurs in animals of three groups: those given carcinogen A alone, those given B alone, and those given both A and B. Synergism was absent in the data examined.