Tumor Cell Surface Antigens

Cancer immunotherapy has made rapid developed over the past decade, including increasing knowledge about how cancer cells can escape of the immune system and the development of new therapies that have been successful in cancer patients. Tumor cells produce antigens that can remain on the cell surface. These antigens, known a tumor antigens, are one of the central factors that play a role in the developments in immunotherapy. These antigens are sometimes presented only by tumor cells and not by normal cells. In this case, these are called tumor-specific antigens (TSAs). Tumor associated antigens (TAA) can also be expressed by normal cells, although they are associated with a malignant cell phenotype. TAAs and TSAs have been an important research subject due to their role in the elimination of tumor cells, and have been reclassified under more specific groups in the following periods. According to the modern classification, tumor antigens are grouped as viral antigens, cell-type specific differentiation antigens, antigens encoded by cancer-testis genes, overexpressed antigens, mutant protein antigens, oncofetal antigens, glycolipids and glioproteins. Nowadays, it is tried to increase their effectiveness by using surgery to prevent or manage cancer, chemotherapy, targeted or radiation treatments, and in combination with immunotherapy methods. Thanks to immunotherapies using tumor antigens (cancer vaccines, bispecific antibodies and chimeric antigen receptor-T therapy), a serious progress has been made in the treatment of cancer today. In this review, subgroups of tumor antigens and their roles in cancer immunotherapy are discussed.