Role of the immunosuppressive microenvironment in immunotherapy

Immunotherapy is reshaping cancer treatment paradigms; however, response rates to immune therapies are low and depend on the host's pre-existing antitumor immunity. The tumor microenvironment is comprised of malignant cells, stroma, and extracellular molecules and can hinder immune control of tumors. Herein, we review how anti-tumor immune responses are formed and how tumors avoid immune destruction. We also outline potential therapeutic targets in the immunosuppressive tumor microenvironment to promote immune control of tumors. (C) 2018 The Authors. Published by Elsevier Inc.