Finn discusses the underdeveloped potential of preventive, rather than therapeutic, cancer vaccines and reviews past successes and current efforts in the development of preventive vaccines for cancers with a viral origin, as well as lessons learned from research and clinical trials, particularly with respect to antigens and the immunosuppressive tumor microenvironment. Finn proposes that pre-malignant lesions, regardless of etiology, should be the next targets of preventive cancer vaccines and reviews relevant past and ongoing clinical trials.

An important role of the immune system is in the surveillance for abnormal or transformed cells, which is known as cancer immunosurveillance. Through this process, the first changes to normal tissue homeostasis caused by infectious or other inflammatory insults can be detected by the immune system through the recognition of antigenic molecules (including tumour antigens) expressed by abnormal cells. However, as they develop, tumour cells can acquire antigenic and other changes that allow them to escape elimination by the immune system. To bias this process towards elimination, immunosurveillance can be improved by the administration of vaccines based on tumour antigens. Therapeutic cancer vaccines have been extensively tested in patients with advanced cancer but have had little clinical success, which has been attributed to the immunosuppressive tumour microenvironment. Thus, the administration of preventive vaccines at pre-malignant stages of the disease holds promise, as they function before tumour-associated immune suppression is established. Accordingly, immunological and clinical studies are yielding impressive results.

Author Info: (1) Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.

Author Info: (1) Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.

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