Cancer immunosurveillance, immunoediting and inflammation: independent or interdependent processes?

When immune cells and developing tumor cells localize to a common microenvironment, an assemblage of interactions takes place; this results in either tumor destruction by way of immunosurveillance or tumor outgrowth. These events put a functional imprint onto the emerging tumor repertoire because tumor cells arising in the presence of a fully functional immune system are less immunogenic than those that develop in the absence of immunity (i.e. in RAG2(-/-) and perforin(-/-) mice). However, other studies suggest that the immune system can also actively promote formation of certain tumors. These apparent disparate effects of immunity on tumorigenesis provide a,unique model for study of the decision-making process that dictates immune function within a tumor.