Mifepristone treatment improves length and quality of survival of mice with spontaneous lung cancer.

Background: There are data showing that human leukemia cell lines have mRNA for an immunomodulatory protein found in normal pregnancy that is stimulated by progesterone. One of the functions of this progesterone-induced blocking factor (PIBF) is to suppress natural killer cell activity. Mifepristone has not only been shown to down-regulate PIBF expression by human leukemic cell lines but has also been shown to prolong and improve the length of life of mice with spontaneous leukemia.

Mifepristone treatment improves length and quality of survival of mice with spontaneous leukemia.

Background: Mifepristone was found to suppress expression of the progesterone-induced blocking factor (PIBF). Progesterone-induced blocking factor suppresses natural killer cell activity. The objective of the present study was to determine if treatment of mice with spontaneous murine lymphocyte leukemia with the progesterone receptor antagonist mifepristone could improve length and quality of life.

Mifepristone may halt progression of extensively metastatic human adenocarcinoma of the colon - case report.

Background: Mifepristone, a progesterone receptor antagonist has been found to improve the length and quality of life in various spontaneous murine cancer models including tumors without progesterone receptors theoretically by inhibiting an immunomodulatory protein that suppresses natural killer cell function in the tumor microenvironment.

Materials And Methods: Mifepristone 200 mg per day by mouth was given to two patients with stage 4 colon cancer with extensive metastases.

Results: Both patients not only survived far longer than expected but had marked improvement in their quality of life similar to mice.