New uses for phenylketone carboxylate compounds and substituted aromatic compounds of Formula I, Formula I.1, Formula I.2, Formula IA, Formula IB, Formula IC and Formula II and their pharmaceutical acceptable salts for the treatment of cancer. The use of a combination of two of these compounds is described and the use of the combination of one of these compounds with an anticancer agent such as decarbazine, doxorubicin, daunorubicin, cyclophosphamide, busulfex, busulfan, vinblastine, vincristine, bleomycin, etoposide, topotecan, irinotecan, taxotere, taxol, 5-fluorouracil, methotrexate, gemcitabine, cisplatin, carboplatin and chlorambucil.