Endocrine changes associated with relapse in advanced breast cancer patients on aminoglutethimide therapy.

About one third of unselected postmenopausal women with advanced breast cancer respond to treatment with aminoglutethimide and hydrocortisone, but they all eventually relapse, and further progression of disease occurs. In this study, 36 patients who initially responded to this treatment were evaluated to determine whether clinical relapse was associated with escape from endocrine suppression. Plasma estrone levels rose significantly (mean increase, 6.8 pg/ml) during the final 15% of time on treatment before relapse. Mean plasma estradiol, dehydroepiandrosterone sulfate, and androstenedione levels also rose with the approach of the relapse, but the increases were not statistically significant. The increase in estrone may contribute to the progression of disease.