Androgen-independent advanced prostate cancer is a terminal malignancy that generally results in death within five years. Its cause has been unknown, and a treatment did not exist. Prevailing views have mistakenly implicated impaired androgen receptor activity in the development of androgen-independent malignancy; which has deterred the existence of an effective treatment. Instead, recent reports have provided evidence that prolactin promotes the development and progression of androgen-independent malignancy; which follows androgen ablation treatment for androgen-dependent prostate cancer. That relationship dictates that a treatment for advanced prostate cancer should suppress the concentration plasma prolactin. This has been achieved with cabergoline (dopamine agonist; Dostinex) treatment of a patient that resulted in 88% decreased plasma prolactin, and terminated the malignancy. That likely represents the first effective treatment for advanced prostate cancer. It remains to establish if this treatment will be successful for other patients with advanced prostate cancer.