Weight-of-Biological Evidence Approach for Assessing Carcinogenicity

Cancer is a complex, multistage, multimechanism phenomenon. Despite this, long-term rodent carcinogenicity studies have been the principal means used to assess the potential carcinogenic effect of compounds. Unfortunately, decades of carcinogenicity testing have failed to provide an unequivocal set of guidelines that determines the true carcinogenic potential of a compound in laboratory animals or humans. Furthermore, there is often considerable debate over what is a biologically significant finding in an individual study. A statistical evaluation helps in assessing the probability that a finding is treatment related, but numerous other factors have an impact on that determination. The data must be evaluated separately and collectively to determine whether the change in question is real.