Endocrine therapy of advanced breast cancer.

Recent research has resulted in several new options for endocrine treatment of advanced breast cancer. Since one of the most intriguing characteristics of endocrine therapy is that new remissions can be achieved when using subsequent endocrine modalities it is of importance to evaluate their optimal sequence. Tamoxifen has become the most commonly used endocrine therapy of advanced breast cancer due to its few side effects and an overall response rate of 35%, which has been obtained in randomized trials of tamoxifen compared with either ablative, additive or inhibitive treatment approaches. Crossover data from these trials indicate that the highest overall response rate is obtained when tamoxifen is used as first line endocrine therapy. Furthermore, it seems that oophorectomy in premenopausal and aminoglutethimide or progestins in postmenopausal patients are equally effective as second line endocrine therapy. Despite an obvious clinical rationale for combined endocrine therapy most trials exploring this concept have failed to show any benefit. Although data from trials combining tamoxifen with prednisolone or androgens seem exciting, the use of combined endocrine therapy still have to be considered experimental.