Abstract OT1-04-02: Mifepristone treatment for breast cancer patients expressing levels of progesterone receptor isoform A (PRA) higher than those of isoform B (PRB)

Seventy percent of breast cancers express estrogen (ER) and progesterone receptors (PR) and respond to antiestrogen therapies. Emerging evidence from experimental studies and human epidemiology, points to a relevant role for progestins in breast carcinogenesis and cancer growth. Others and we have proposed that there is a role for antiprogestins in the therapeutic armamentarium, but the challenge remains to identify which patients would benefit...