Endocrinology and hormone therapy in breast cancer: endocrine therapy in premenopausal women.

Endocrine therapy remains important in premenopausal women with hormone receptor positive breast cancer. Ovarian ablation, used alone, is effective in delaying recurrence and increasing survival in such women. When added to chemotherapy, it is less clear that it is effective perhaps because of the endocrine ablative effect of chemotherapy. Trials comparing ovarian ablation with or without tamoxifen to CMF-type chemotherapy suggest that the endocrine therapy is equivalent to or better than this chemotherapy in women whose tumors have estrogen and/or progesterone receptor. Tamoxifen is also effective in preventing recurrence and prolonging survival in the adjuvant setting in premenopausal women. While most of the available data deals with tamoxifen given alone, it appears to have a similar beneficial effect when added to chemotherapy in the premenopausal adjuvant setting. Adjuvant aromatase inhibitors should not be used in premenopausal women.