The present invention relates to the field of medicine, and refers to the steroid compound 4-hydroxyandrost-4-ene-3,17-dione (4-OHA) or ester thereof, as a prodrug for use in the treatment of a patient suffering from estrogen-receptor β (ERβ) positive breast tumour. The present invention further relates to a pharmaceutical composition comprising said steroid compound for topical application, and the use of said steroid compound in a pre-surgical topical treatment of ERβ-positive breast cancer tissue.
