Semiparametric analysis of tumor incidence rates in survival/sacrifice experiments.

This paper addresses the problem of comparing treatment groups with respect to the rate of tumor development for animals in a survival experiment with some serial sacrifices. The analysis specifies a parametric model for the tumor incidence function, but places no parametric restrictions on the death rates. The procedure is feasible with as few as two sacrifice times and requires no individual data on cause of death. Other diseases need not act independently of the tumor of interest, nor are any restrictions imposed on tumor lethality or the relationship between the onset and death times for tumor-bearing animals. The proposed methods are illustrated with some survival/sacrifice data.