The present invention provides methods for treating a cancer in a subject and for inhibiting tumor growth, metastasis or a dihydrorotate oxygenase enzyme activity of a tumor or cancer cell. At least one trisubstituted benzotriazole derivative with the formula (I) is administered to the subject or is contacted with the cancer cell. Compounds of formula (I) have substituents R1, R2 and R3 which have the meanings given in the specification, and pharmaceutically acceptable salts thereof.