Prostate cancer immunotherapy at the dawn of the new millennium

Standard treatments for adenocarcinoma of the prostate, such as surgery, ho rmones, radiation and chemotherapy, often achieve a clinical response, but this is usually short-lived. Prostate cancer frequently recurs and second-l ine therapies have a poor response rate. Many clinicians seem comfortable i n limiting their philosophy of treating advanced recurrent disease merely t o new regimens of failed therapies, such as combination chemotherapy. Howev er, other medical researchers have chosen to pursue novel approaches, inclu ding immunotherapy, several of which are summarised in this review. Althoug h ranging widely in antigen specificity, all attempt to exploit the body's natural antitumour immunity. Furthermore, all aim to stimulate immunity abo ve a threshold level necessary for tumour regression or to induce stability in the face of progression. The goal of in vivo or ex vivo gene therapy is the modification of gene expression within an antigen-presented cell by th e introduction of a vector, DNA, or RNA. Within that field, much progress h as been made and is ongoing currently concerning gene delivery systems, tar get identification and characterisation. Comparatively, monoclonal antibodi es are an established type of cancer immunotherapy. However, the more recen t development of humanised or fully human antibodies, as well as novel moie ties they can be coupled to, renews their prospects for clinical impact. La stly, various cell-based therapies are the focus of several recent clinical studies demonstrating tumour regression or stabilisation. Immune cells, fo r example, T-lymphocytes and dendritic cells, have already demonstrated tre atment benefit, as well as the ability to maintain an excellent quality of life for participants. Overall, there is a multitude of approaches being co nsidered for the treatment of prostate cancer. The following review concent rates on those approaches that are currently in human or animal studies and have a specific emphasis on prostate cancer.