A clinical trial of aminoglutethimide in advanced postmenopausal breast carcinoma: low response in patients previously treated with medroxyprogesterone.

In an attempt to define the influence of prior hormonal treatments upon aminoglutethimide activity in advanced cancer of the breast, 42 heavily pretreated postmenopausal patients received aminoglutethimide, 4 X 250 mg daily, with hydrocortisone or cortisone. Twenty-six received high doses of medroxyprogesterone before entering this study. There was no significant difference in patients' characteristics with or without medroxyprogesterone pretreatment. A comparison of patients with and without prior medroxyprogesterone shows a significant difference in the response rate to aminoglutethimide-hydrocortisone (4 vs 32%, P = 0.02). In patients pretreated with tamoxifen but not with medroxyprogesterone the response rate to aminoglutethimide was 36%. These results suggest that aminoglutethimide has a low activity in breast cancer patients previously exposed to medroxyprogesterone, an agent with glucocorticoid-like activity inducing adrenal suppression.