Dictionary of Cancer Terms
View in Spanish: RP(-)
PR-
Describes cells that do not have a protein to which the hormone progesterone will bind. Cancer cells that are PR- do not need progesterone to grow, and usually do not stop growing when treated with hormones that block progesterone from binding. Also called progesterone receptor negative.
Source: National Cancer Institute Dictionary of Cancer Terms, available at www.cancer.gov/dictionary.