A drug used to treat prostate cancer that has spread to other parts of the body. It is used in patients who have had surgery to remove the testicles (orchiectomy). Nilutamide binds to proteins called androgen receptors, which are found in some prostate cancer cells. These proteins bind to androgens (male hormones) and may cause cancer cells to grow. Nilutamide blocks these proteins and may keep cancer cells from growing. It is a type of antiandrogen. Also called Nilandron.