Disclosed herein is a method for treating and preventing prostate cancer, and particularly androgen-independent prostate cancer, the method including administering to a mammal a benzothiopene having the formula ##STR00001## or pharmaceutically acceptable salts or prodrugs thereof, wherein R and R.sub.1 are each independently selected from the group consisting of hydrogen, --COR.sub.2, --COR.sub.3, and R.sub.4; R.sub.2 is selected from the group consisting of hydrogen, C1-C14 alkyl, C1-C3 chloroalkyl, C1-C3 fluoroalkyl, C5-C7 cycloalkyl, C1-C4 alkoxy, and phenyl; R.sub.3 is phenyl with at least one substitution selected from the group consisting of C1-C4 alkyl, C1-C4 alkoxy, hydroxy, nitro, chloro, fluoro, trichloromethyl, and trifluoromethyl; R.sub.4 is selected from the group consisting of C1-C4 alkyl, C5-C7 cycloalkyl, and benzyl; and R.sub.5 is selected from the group consisting of oxygen and --C.dbd.O. The method may further include the administration of an estrogen lowering drug to enhance efficacy of the compound of the present invention.