Trilostane in the treatment of advanced breast cancer.

The combination of trilostane 960 mg daily and either dexamethasone 0.5 mg b.d. or hydrocortisone 10 mg b.d. has been used to treat advanced metastatic breast cancer in post-menopausal women. Twenty-three patients had assessable disease and received treatment for a minimum of 8 weeks. Six (26%) showed an objective response and three (13%), stabilisation of previously progressive disease, sustained for at least 3 months. Side-effects were mainly gastrointestinal. Biochemical studies suggest that the mechanism of action may be inhibition of conversion of androstenedione to oestrone.