The role of aromatase inactivators in the treatment of breast cancer.
Third-generation aromatase inhibitors and inactivators have earned their place in the treatment of metastatic breast cancer. The third-generation aromatase inactivator exemestane was found to be superior to megestrol acetate as second-line endocrine therapy in postmenopausal women, with respect to time to progression as well as overall survival, and the results from an ongoing study comparing exemestane with tamoxifen in first-line treatment are promising. The finding that exemestane may also work in patients previously exposed to nonsteroidal aromatase inhibitors reveals lack of complete cross-resistance between the compounds. Currently, exemestane given as monotherapy, or in sequence with tamoxifen (2-3 + 3-2 years of tamoxifen-exemestane or 5 years of tamoxifen followed by 2 years of exemestane) is being compared with tamoxifen 5 years monotherapy in the adjuvant setting. In addition, we are currently addressing the toxicity of exemestane in a placebo-controlled trial in low-risk breast-cancer patients. The results from these studies will outline the potential role of exemestane in adjuvant treatment and, potentially, for breast-cancer prevention in postmenopausal women.
Department of Oncology, Haukeland Hospital, University of Bergen, N - 5021 Bergen, Norway. plon@haukeland.no
Per Eystein
PE
Lønning
D000730:Androstadienes / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D047072:Aromatase Inhibitors; D001943:Breast Neoplasms / Q000188:drug therapy*; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D005260:Female; D006801:Humans
D000730:Androstadienes; D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D004791:Enzyme Inhibitors; C056516:exemestane