Medrogestone and an LHRH analogue as potential combination therapy for hormone-dependent cancers.

Treatment (5 mg/kg s.c. for 1 to 4 weeks) of adult male rats with medrogestone (Colprone), a compound with progestational and antiandrogenic properties, induced significant atrophy of the ventral prostate without affecting testicular weight, testicular LH/hCG receptor levels or plasma testosterone. The potent LHRH agonist (D-Ala6, des-Gly-NH210) LHRH ethylamide at 500 ng s.c. for 2-4 weeks suppressed the testicular weight, testicular LH/hCG receptor levels, plasma testosterone levels, and caused atrophy of the androgen-dependent seminal vesicles and ventral prostate. The combination 4 week-treatment of medrogestone and LHRH agonist led to the most significant decrease of prostatic weight. The potential usefulness of this combination therapy in hormone-dependent cancers is discussed.