The present invention provides methods for treating a cancer in a subject andfor inhibiting tumor growth, metastasisor a dihydrorotate oxygenase enzyme activity of a tumor or cancer cell. Atleast one trisubstituted benzotriazole derivative with theformula (I) is administered to the subject or is contacted with the cancercell. Compounds of formula (I) have substituents R1, R2 andR3 which have the meanings given in the specification, and pharmaceuticallyacceptable salts thereof.