Indication for use in combination with surgical castration for the treatment of metastatic prostate cancer involving distant lymph nodes, bone, or visceral organs (stage d2).mechanism of action nilutamide competes with androgen for the binding of androgen receptors, consequently blocking the action of androgens of adrenal and testicular origin that stimulate the growth of normal and malignant prostatic tissue. this blockade of androgen receptors may result in growth arrest or transient tumor regression through inhibition of androgen-dependent dna and protein synthesis.