Predicting carcinogenicity by using batteries of dependent short-term tests.

Among the various methods for predicting carcinogenicity from a battery of short-term tests (STTs), the carcinogenicity prediction and battery selection (CPBS) procedure is the most prominent. A major assumption of CPBS is that the STTs used in the prediction are conditionally independent. Results of recent National Toxicology Program studies of four commonly used in vitro STTs contradict this assumption, thereby necessitating modification of CPBS to accommodate dependencies. This is accomplished via log-linear modeling, which then also yields an important dividend: standard errors for the predicted probabilities of carcinogenicity.