Chemohormonal therapy and endocrine function in breast cancer patients.

The administration of CMFVP (cyclophosphamide, methotrexate, 5-fluorouracil, vincristine, and prednisone) results in profound alterations in hormonal profiles of premenopausal women due to a reduction in ovarian and adrenal secretion of estrogens and androgens. Cytotoxic chemotherapy results in ovarian suppression as documented by decreases in estradiol with concomitant elevations in pituitary gonadotrophins, whereas the addition of prednisone to the cytotoxic regimen results in significant decreases in androgen levels due to adrenal suppression. In postmenopausal women, CMFVP also results in significant decreases in estrogens and estrogen precursors due to suppression of adrenal steroid metabolism. Continuous low-dose prednisone administration during cytotoxic chemotherapy appears to be more effective than an intermittent high-dose schedule in achieving and sustaining adrenal suppression. However, complete elimination of adrenal steroidogenesis does not occur in all cases since measurable amounts of adrenal steroids remain in the serum throughout chemohormonal therapy. The administration of tamoxifen plus CMFVP is associated with hyperestrogenemia in younger premenopausal patients which persists until the onset of ovarian suppression.