Daily oral administration of DHEA (Dehydroepiandrosterone) at the dosage of 100 mg/die in combination with a daily oral administration of anastrozole at dosage of 1 mg/die or letrozole at the dosage of 2.5 mg/die or exemestane at the dosage of 25 mg/die without interruption until discontinuation for progression of disease, unacceptable toxicity or discontinuation/withdrawal of participants from study treatment.