Cancer and the tumor microenvironment

Abstract

Formerly referred to as a group of altered cells in proliferation, today cancer is better understood as a microenvironment, in which the interactions between the cellular and molecular elements are determinative in tumor progression. As a result, the comprehension of a neoplasic event gains increasing complexity. The dynamics of the tumor cells are now analyzed as part of a true tumoral tissue, subject to conditions of vascularization, oxygenation, interstitial pressure and tissue necrosis, which influence tumor kinetics. New components of this tumoral niche and their respective actions are being identified. Among these constituents are the elements of the immune system which, as a series of experiments have shown, are involved in the aspect of immunosurveillance, as negative selective pressure, as well as in mechanisms of tumor progression. This review will analyze neoplasia as a tumor microenvironment, focusing on immunological participation and on tumor kinetics, and exposing the main ideas and discoveries that created and are improving the concept of cancer