Inflammation versus adaptive immunity in cancer pathogenesis

Cancer pathogenesis is initiated and modulated in an interplay between the malignant transformed cells, the surrounding stroma, and the innate and adaptive immune system. These interactions are complex, and components of the immune system act as both defense mechanisms against and contributors to tumor initiation, tumor growth, invasivity, and development of metastases. Inflammatory conditions help to establish a microenvironment promoting cancer development, whereas a malignant tumor feeds the inflammatory response and accelerates tumor growth. However, mouse models and epidemiological and clinical data demonstrate that an intact immune system is associated with a favorable prognosis, although the inflammatory response and the adaptive immune system share many cellular and humoral features. Here, we review the emerging concepts in cancer pathogenesis where the inflammatory and adaptive components of the immune system play an important role in the interaction with the tumor and stromal tissue.