Management of Hormone-Refractory Prostate Cancer

Abstract

Prostate cancer represents one of the prime examples of hormone-dependent cancers. Although most of the patients respond to the different types of androgen deprivation therapy but this effect usually does not last for long time, as the tumor becomes hom1one-resistant and starts to grow again in spite of androgen ablation. The development of hormone-refractory state occurs in most of the patients after an almost predictable time after the onset of hormonal therapy. This period of time ranges between 2-3 years in most of the clinical studies. Recently, there has been a great development in the treatment of homwne­ refractory prostate cancer. Traditionally, metastatic disease that failed hom10nal therapy was managed only by palliation and symptomatic treatment of complications. NO\v, there are many different treatment modalities with response rate ranging up to 50% in rnost of the clinical trials. Patients on hormonal treatment by antiandrogens may respond to withdrawal of the antiandrogen with regression of the disease in 1 5-30% of cases. Some patients may respond to adrenal androgen inhibitors e.g. aminoglutethi mide (30% response rate) and ketoconazole (60% response rate). Other patients respond to corticosteroids (20-70% response rate). ln the last few years, several chemotherapeutic combinations have been developed e.g. estramustine with etoposide (40-60% response rate), estramustine with paclitaxel (30-50% response rate), mitoxantrone with prednisone (30% response rate) and estramustine with etoposide and paclitaxel (50% response rate). Suramin is a new chemotherapeutic that act by blocking the action of an oncogene, with response rate of 30% in clinical trials.