Treatment of advanced breast cancer in postmenopausal women with 4-hydroxyandrostenedione.

4-Hydroxyandrostenedione (4-OHA), a new specific aromatase inhibitor, was used to treat 57 postmenopausal women with advanced breast cancer at a dose of 250 mg by i.m. injection every 2 weeks; 55 women were assessable for response. In all, 18 patients (33%) had objective evidence of a response to treatment, with a median duration of 12 months; the disease stabilised in 8 (14%) patients. Serum oestradiol levels, which were measured weekly in nine of the patients, were found to be suppressed to a mean of between 36% and 51% of pretreatment levels during the first 6 weeks of treatment. Three patients were withdrawn from treatment because of toxicity (pain at injection site, sterile abscess and rash). One patient had an isolated episode of anaphylaxis after 6 months of treatment. In comparison with our previous reports of 4-OHA treatment, a dose of 250 mg given i.m. fortnightly appears to be the optimal dose regimen. The efficacy of the drug seems to be similar to that of tamoxifen and aminoglutethimide.