Endocrine and clinical consequences of combination tamoxifen-aminoglutethimide in postmenopausal breast cancer.

By analogy with combination chemotherapy, endocrine agents with different mechanisms of action have been combined in the treatment of patients with advanced breast cancer. The clinical use of tamoxifen+aminoglutethimide+hydrocortisone showed no clinical benefit over the individual use of tamoxifen or aminoglutethimide+hydrocortisone. The endocrine changes occurring in postmenopausal patients as a consequence of their treatment with tamoxifen+aminoglutethimide+hydrocortisone have been examined. Suppression of gonadotrophin and oestrogen levels and increased levels of sex hormone binding globulin were observed. These changes might be expected to be of benefit in the treatment of advanced breast cancer, and do not explain the lack of clinical benefit in combining the treatments. Non-responders to this combination therapy had higher levels of oestrone and dehydroepiandrosterone sulphate whilst on treatment than responders, confirming previous observations in patients treated with aminoglutethimide+hydrocortisone.