In the drug textbook (Abrams),
nilutamide is included as an antiandrogen used for treatment of prostate cancer.
On the next page, nilutamide is not included with the other antiandrogens, instead it is included with goserelin, leuprolide, and triptorelin under the heading LHRH Analogs, and its clinical uses are indicated as "advanced breast cancer in postmenopausal women".
Other sources that I have checked say that nilutamide is an antiandrogen for prostate cancer.
Is nilutamide ever used to treat breast cancer in postmenopausal women?