Genetic toxicity and potential carcinogenicity of taxol.

The activity of the antineoplastic agent taxol depends upon its ability to inhibit tubulin disassembly in dividing cells. We show here that taxol gives a strong positive response in the mouse bone marrow micronucleus assay. This is the first report of its genetic toxicity. The majority of antineoplastic agents are carcinogenic to humans, and the majority of human carcinogens are active in the mouse bone marrow micronucleus assay. The present data therefore indicate a carcinogenic potential of taxol for humans, which should be considered in the risk-benefit analysis of its increasing clinical use.