Which agent is specifically indicated for advanced prostate cancer?

Nilutamide is specifically indicated for advanced prostate cancer, particularly in the treatment of metastatic castration-resistant prostate cancer. It is an androgen receptor antagonist that works by blocking the effects of testosterone on prostate cancer cells, which can help to slow the growth of tumors. This mechanism is vital in the management of advanced prostate cancer, where the cancer has progressed despite hormonal therapy.

Goserelin is also used in the treatment of prostate cancer but is primarily a GnRH analog that reduces the production of testosterone by the testes. While effective, it is not the direct androgen receptor blocker that is indicated for advanced stages in the same way that nilutamide is.

Ribociclib is a CDK4/6 inhibitor primarily used in breast cancer, not prostate cancer. It functions by disrupting the cell cycle, which is not the primary therapeutic approach for prostate cancer.

Trastuzumab is utilized for cancers that overexpress the HER2 protein, such as certain breast cancers, and is not indicated for prostate cancer. Thus, nilutamide stands out as the agent specifically indicated for treating advanced prostate cancer due to its targeted action on androgen receptors.