Wirkungsweise und Stellenwert der neuen Aromatasehemmer in der Therapie des Mammakarzinoms

Blocking estrogen synthesis in postmenopausal patients can inhibit proliferation of hormone-sensitive breast cancer. New aromatase inhibitors prevent the aromatization in the enzymatic conversion of androgens to estrogens. Both tamoxifen, which competes with estradiol at the receptor, and the aromatase inhibitors have the effect of abrogating proliferative effects of estrogens. The third-generation aromatase inhibitors anastrozole and letrozole are nearly free of side effects, can be administered orally, and have been found to be superior to megestrol acetate. Also, letrozole has been shown to be more effective than aminoglutethimide, the first-generation aromatase inhibitor. Clinical trials comparing the new and more specific aromatase inhibitors with tamoxifen in patients with hormone-sensitive breast cancer are underway.