The changing natural history of metastatic prostate cancer.

Since 1941, the understanding of prostate cancer pathogenesis and therapy has undergone a significant transformation. Rigorous translational research has identified multiple mechanisms underlying castration resistance, the fatal clinical state of the disease. Therapeutic approaches targeting these mechanisms in metastatic castration-resistant prostate cancer have now been clinically validated in the clinic including high-potency androgen signaling inhibition, novel cytotoxic chemotherapy, and bone-targeted therapies. Despite these advances, cure remains an elusive goal. The natural history of metastatic prostate cancer has evolved particularly in the last 2 decades in step with improved management of age-associated comorbidities, improved imaging, and the expansion of novel therapies, thus providing new opportunities and challenges. It is also important to note that the advent of prostate-specific antigen testing caused a stage shift in the disease spectrum, thus leading to earlier interventions and potentially positively impacting survival. The optimal sequencing and combinations of available therapies, predictive biomarkers, and better understanding of mechanisms of resistance remain high priority. Further refinement of the clinical niche for novel therapies in hormone-sensitive and castration-resistant disease through rationally designed clinical trials incorporating molecular, clinical, and imaging biomarkers and quality-of-life correlatives is of paramount importance.