Effect of 7β, 17α-dimethyltestosterone (Calusterone) on cortisol metabolism in women with advanced breast cancer

It was demonstrated that oral administration of 7β, 17α-dimethyltestosterone (Calusterone) reversibly alters cortisol production and metabolism in women with advanced breast cancer. There was a 30% decrease in cortisol production rate, a 50% decrease in transformation to tetrahydrocortisone (THE) glucuronide, a 50% prolongation of plasma cortisol half-life, and decreased conversion to C-19 metabolites. The plasma cortisol concentrations (means and 24-hour profiles) remained unchanged by Calusterone despite the reduction in adrenocortical function. We have concluded that the beneficial effect of Calusterone in breast cancer is probably not due to its effects on cortisol production.