Progesterone receptor antagonist therapy has therapeutic potential even in cancer restricted to males as evidenced from murine testicular and prostate cancer studies.

Abstract

These data support the hypothesis that various cancers may utilize a mechanism that is present in normal pregnancy that involves secretion of a progesterone-induced protein that blocks natural killer cell activity. The hypothesis that the cancer cells have the capacity to direct local progesterone production is supported by demonstrating the benefit of a progesterone receptor antagonist in tumors restricted to males.