Immunotherapy and immunoselection - tumour escape as the final hurdle

Tumours are immunogenic and are commonly infiltrated by anti-cancer effector cells. Why, then, are they not completely rejected by the host? Unfortunately, tumours are Darwinian paragons, winning the battle against the forces of natural immune selection. Some of the latter can even act as double-edged swords, actually being subverted to become protumorigenic. Prevention or reserval of tumour escape from the immune response therefore offers the possibility of reconstructing effective anti-tumour immunity and remains the major challenge for 21st century tumour immunology. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.