Endocrine function in premenopausal and postmenopausal advanced breast cancer patients treated with CMF or tamoxifen.

The effect of CMF (cyclophosphamide, methotrexate and 5-fluorouracil) or tamoxifen treatment on endocrine function was investigated in premenopausal and postmenopausal breast cancer patients. CMF therapy resulted in ovarian failure but pituitary and adrenal functions were unaffected in premenopausal patients. Although amenorrhea was achieved within two to five months in older patients, younger patients required large cumulative doses of cytotoxic drugs to exhibit ovarian dysfunction. CMF therapy had no effect on hormonal levels in postmenopausal patients indicating that in this group therapeutic response is not mediated via the endocrine system. On the other hand, tamoxifen therapy in postmenopausal patients resulted in hyperestrogenemia.