Recent advances in hormonal treatment of breast cancer

Hormonal therapy in patients with breast cancer is based on estrogen blocka de of tumor cell growth. In postmenopausal patients tamoxifen still represe nts the hormonal agent of first choice and has shown to induce remission in patients with metastatic disease, to reduce recurrence, and to improve ove rall survival in the adjuvant setting. However, side effects such as slight ly increased incidence of endometrial cancer have stimulated the search for other substances. Substantial progress in the development of anti-estrogen s have yielded in substances with different antagonistic/agonistic profils (Toremifen, Raloxifen, Droloxifen, Idoxifen, ICI 182,780), which are curren tly tested in phase II and III studies. In the group of the aromatase inhib itors, which are mostly used in second-line protocols, new compounds are on the market (Formestan, Anastrazol, Letrozol, Vorozol, Fadrozol) which circ umvent the main problem of inhibition of the glucocorticoid synthesis of th e first-generation drugs (glutethimide) by better specificity. These alread y are widely used in patients with tamoxifen-resistant tumors. Whether thes e substances can also improve the outcome in first-line therapy is currentl y under clinical evaluation. An additional therapeutic intervention is the pharmacological castration (Goserelin), which orginates from the optimistic result of the surgical castration earlier days. This concept is used in pr emenopausal patients and currently studied alternatively and in addition to tamoxifen. In general there is hope to improve efficacy and to reduce side effects of endocrine treatment with these new compounds in the near future .