Figure 4.

Immunosurveillance, tumor-promoting and therapy-induced inflammation.

A) Balance between immunosurveillance and tumor promoting inflammation in the tumor microenvironment. Tumor promoting cytokines act on immune and malignant cells to tilt the balance toward tumor promotion. Tumor promoting immunity dampens immunosurveillance, which otherwise inhibits tumor growth. B) Therapy-induced inflammation. Various forms of therapy induce death (necrosis) of malignant cells resulting in the release of necrotic products and damage-associated molecular patterns (DAMPs) that activate cytokine-producing inflammatory cells. These cytokines activate pro-survival genes in residual cancer cells, rendering them resistant to subsequent rounds of therapy. However, in some cases, therapy-induced inflammation augments the presentation of tumor antigens and stimulates an anti-tumor immune response that improves the therapeutic outcome.