Figure 3. Three stages of immunoediting and cancer response to immunotherapy.

The progression of cancer depends on three stages of immunoediting: (1) elimination, (2) equilibrium, and (3) escape. As cancer cells remain undetectable during the initial two stages, the over-expression of T-lymphocytes in the final stage induces immunosuppression. The illustration demonstrates the potential application of immunotherapy in its ability to overcome the tumor response and cause regression of cancerous cells.

Abbreviations – NK: natural killer; Th1: type 1 helper T cell; IL-12: interleukin-12; IFN-γ: interferon-γ; MDSC: myeloid-derived suppressor cell.