Tumor Antigen - Classification of Tumor Antigens

Classification of Tumor Antigens

Initially they were broadly classified into two categories based on their pattern of expression: Tumor-Specific Antigens (TSA), which are present only on tumor cells and not on any other cell and Tumor-Associated Antigens (TAA), which are present on some tumor cells and also some normal cells.

This classification, however,is imperfect because many antigens thought to be tumor-specific turned out to be expressed on some normal cells as well. The modern classification of tumor antigens is based on their molecular structure and source.

Accordingly they can be classified as;

• Products of Mutated Oncogenes and Tumor Suppressor Genes
• Products of Other Mutated Genes
  • Overexpressed or Aberrantly Expressed Cellular Proteins
  • Tumor Antigens Produced by Oncogenic Viruses
  • Oncofetal Antigens
  • Altered Cell Surface Glycolipids and Glycoproteins
  • Cell Type-Specific Differentiation Antigens