Treatment with formestane alone and in combination with aminoglutethimide in heavily pretreated breast cancer patients: clinical and endocrine effects.
We studied the clinical and endocrine effects of the aromatase inhibitor formestane (4-hydroxyandrostenedione, 4-OHA) in heavily pretreated breast cancer patients (median number of previous endocrine treatments 2, range 1-4). Of 30 patients eligible for response evaluation, 3 patients (10%) showed a partial response while 11 patients (36.7%) experienced stable disease over a time period of at least 6 months. Plasma levels of oestrone, oestradiol and oestrone sulphate were found suppressed to a mean of 33.9, 35.6 and 24.2% of control values. 4 of 6 patients experienced a further substantial reduction in plasma oestrone sulphate to < 5% of pretreatment values when aminoglutethimide (AG) was added after relapse on 4-OHA monotherapy. Our findings suggest that these aromatase inhibitors may suppress plasma oestrogen levels by a percentage approaching the percentage inhibition of in vivo aromatisation measured by tracer techniques.
Geisler
J
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Department of Therapeutic Oncology and Radiophysics, University of Bergen, Norway.
Johannessen
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Anker
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Lønning
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D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000616:Aminoglutethimide / Q000008:administration & dosage; D000735:Androstenedione / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D047072:Aromatase Inhibitors; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D004967:Estrogens / Q000097:blood; D005260:Female; D006801:Humans; D008875:Middle Aged
D047072:Aromatase Inhibitors; D004967:Estrogens; D000616:Aminoglutethimide; D000735:Androstenedione; C014594:formestane