Discloses the use of an anti-progestin composition in the preparation of a medicament for the treatment of a tumor susceptible to growth inhibition by one or more anti-progestin(s), wherein the tumor is identified as susceptible to growth inhibition by one or more anti-progestin(s) wherein a) a tissue sample suspected of being tumorigenic from a patient is exposed to an anti-progesterone receptor antibody b) flow cytometry is performed on the tissue sample to identify progesterone receptor positive cells c) high magnification microscopy is used to identify activated progesterone receptor foci in the progesterone receptor positive cells and d) the focal binding distribution of the progesterone receptor in nuclei of cells from the tissue is determined, wherein if the focal binding distribution is greater than 5% of the progesterone receptor positive cells in the tissue sample with an A or AD binding pattern, then the tumor is determined to be susceptible to growth inhibition by one or more anti-progestin(s).
