Metastatic castration-resistant prostate cancer. Part 1: the challenges of the disease and its treatment1

Prostate cancer is the most commonly occurring solid tumour in men and the second highest cause of cancer deaths. For early stage disease surgery and/or radiation is often curative, and for locally advanced or metastatic disease initial treatment involves removing the drive to tumour growth provided by androgens, via androgen deprivation therapy. In the majority, this treatment eventually fails and castration-resistant prostate cancer (CRPC) develops – a condition with usually a poor prognosis and significant impact on quality of life. For many years mitoxantrone was the only chemotherapy for CRPC, but it had only a palliative effect with no effect on survival. This was followed by docetaxel – the first agent to show an increase in overall survival in metastatic CRPC. Recently, newer agents with different modes of action have been developed. These include the novel taxane, cabazitaxel (which has shown superiority to docetaxel), abiraterone (an anti-androgen), alpharadin (a radionucleotide), sipuleucel-T (a cellular immunotherapy product) and enzalutamide (an androgen receptor blocker), all of which are superior to placebo. This article reviews CRPC and the results of studies with these agents.