Progesterone Receptor (PR)

The progesterone receptor (PgR) is an estrogen-regulated protein. It has been proposed that expression of PgR indicates a responsive estrogen receptor (ER) pathway.A number of studies have shown that PgR determination provides supplementary information to ER, both in predicting response to endocrine therapy and estimating survival. PgR has proved superior to ER as a prognostic indicator in some studies.