Developments in cancer vaccination.

The clinical application of cancer vaccines has progressed steadily from the rapid preclinical, technological advances of recent years. Cancer vaccine development has followed to some extent the pattern of vaccination for infectious disease, although features, such as the need to treat established disease in the face of immune evasion, vary. The necessity of conducting safety testing of new therapies in advanced cancer patients rather than in early-diagnosed patients often means that therapeutic benefit is seldom observed. Data that support even limited clinical efficacy are therefore encouraging. Initial approaches using whole irradiated tumor cells continue with some success, although there has been some refinement involving the use of tumor antigens and their subunits in a protein/peptide form (often via manipulated dendritic cells) or as DNA and RNA delivered naked or by viruses. Appropriate modes of boosting the immune system and immune conditioning appear important. Cancer vaccination research is likely to continue along many paths before any approaches become mainstream.