The Immunobiology of Cancer: From Tumor Escape to Cancer Immunoediting Towards Immunotherapy in Gynecologic Oncology

The immune system is known to play a pivotal role in cancer pathogenesis. In a dynamic balance between immune system and cancer cells, the first one recognizes the second as non-self and effectively clears them from the system. This phenomenon, called immune surveillance, is based on the interaction between antigen presenting cells and T lymphocytes that get activated eliciting a specific and enduring response. In certain circumstances, tumor cells are able to evade this mechanism allowing the tumor to develop. This mechanism is called tumor escape. The role of immunotherapy is to restore a balance between immune system and tumor cells by boosting the former. In the past, drugs that work on the immune system in various malignancies have shown striking result, in both response rates and survival, which has led to their FDA approval. The use of these new drugs is currently being investigated with promising results in various other settings, including gynecological malignancies. The definition of immunotherapy encompasses various treatment strategies that include tumor antigen–targeted monoclonal antibodies, immunological checkpoint inhibitors, cytokines, and therapeutic cancer vaccines. These treatments differ as they use distinct mechanisms of actions. However, they all share the fact that their anti-tumor effect is exerted through a boost or a restoration of the immune system. Owing to its potential to affect mutating cancer cells through the dynamic interplay between cancer and the immune system, immunotherapy offers the potential for durable clinical effects and synergy with subsequent therapies.