Antagonism of aminoglutethimide and danazol in the suppression of serum free oestradiol in breast cancer patients.
The response rate of advanced postmenopausal breast cancer patients to treatment with aminoglutethimide (AG) + danazol was significantly worse than that with AG alone. The suppression of serum oestradiol levels by AG + danazol was similar to that by AG alone, but the combination treatment also suppressed sex hormone binding globulin (SHBG) levels and increased the % free oestradiol, whilst these parameters were unaffected by AG alone. The degree of suppression by AG + danazol of free oestradiol concentrations was less than the suppression of total oestradiol level and in some patients the concentration of the free fraction was increased above pretreatment levels. These effects on the presumed biologically active unbound fraction of oestradiol may explain the poor clinical response rate to AG + danazol.
D000616:Aminoglutethimide / Q000037:antagonists & inhibitors / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D003613:Danazol / Q000037:antagonists & inhibitors / Q000627:therapeutic use*; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011245:Pregnadienes / Q000627:therapeutic use*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism
D011245:Pregnadienes; D012738:Sex Hormone-Binding Globulin; D000616:Aminoglutethimide; D004958:Estradiol; D003613:Danazol