The present invention relates to the single use of the progesterone-recep tor antagonist 11.beta.-(-4-acetylpheny)-17 .beta.-hydroxy-17.alpha.-(1,1,2, 2,2-pentafluoroethyl)- estra-4,9-dien-3-one or a pharmaceutically acceptable derivative or analogue thereof for the prophylaxis and treatment of BRCA1- or BRCA2-mediated breast cancer, as well as to a combination comprising the progesterone- receptor antagonist 11 .beta.-(4-acetylphenyl)-17.beta.-hydrox y-17.alpha.-(1,1,2,2,2- pentafluoroethyl)-estra-4,9-dien-3-one or a pharmace utically acceptable derivative or analogue thereof, together with at least o ne pure antiestrogen, for the prophylaxis and treatment of BRCA1- or BRCA2-m ediated breast cancer, ovarian cancer endometrial cancer, gastric cancer, co lorectal cancer.endometriosis, myeloma, myoma and meningioma. The present in vention also relates to a combination of the progesterone-receptor antagonis t 11 .beta.-(4-acetylphenyl)-17.beta.-hydroxy-17.alpha.-(1,1,2,2,2-pentafluo roethyl)-estra-4,9- dien-3-one or a pharmaceutically acceptable derivative o r analogue thereof, together with at least one EGF or EGFR targeting drug, f or the prophylaxis and treatment of BRCA1- or BRCA2-mediated breast cancer, ovarian cancer endometrial cancer, gastric cancer, colorectal cancer, endome triosis, myeloma, myoma and meningioma.
PROGESTERONE-RECEPTOR ANTAGONIST FOR USE IN BRCA ALONE OR ASCOMBINATIONWITH ANTIESTROGEN