Immunotherapy in Pancreatic Adenocarcinoma: Beyond "copy/Paste

Immunotherapy has dramatically changed the cancer treatment landscape during the past decade, but very limited efficacy has been reported against pancreatic cancer. Several factors unique to pancreatic cancer may explain the resistance: the well-recognized suppressive elements in the tumor microenvironment, the functional and structural barrier imposed by the stroma components, Tcell exhaustion, the choice of perhaps the wrong immune targets, and microbial factors including gut dysbiosis and the unexpected presence of tumor microbes. Furthermore, we discuss various strategies to overcome these barriers. _2021 The Authors; Published by the American Association for Cancer Research.