Template-type: ReDif-Paper 1.0 Author-Name: Bayer, Péter Author-workplace-name: Microeconomics & Public Economics, RS: GSBE ETBC Author-Name: Brown, Joel Author-Name: Stankova, Katerina Author-workplace-name: DKE Scientific staff, RS: FSE DKE NSO Title: A Two-Phenotype Model of Immune Evasion by Cancer Cells Abstract: We propose a model with two types of cancer cells differentiated by their defense mechanisms against the immune system. ``Selfish'' cancer cells develop defense mechanisms that benefit the individual cell, whereas ``cooperative'' cells deploy countermeasures that increase the chance of survival of every cell. Our phenotypes capture the two main features of the tumor's efforts to avoid immune destruction, crypticity against immune cells for the selfish cells, and tumor-induced immunosuppression for the cooperative cells. We identify steady states of the system and show that only homogeneous tumors can be stable in both size and composition. We show that under generic parameter values, a tumor of selfish cells is more benign than a tumor of cooperative cells, and that a treatment against cancer crypticity may promote immunosuppression and increase cancer growth. Series: GSBE Research Memoranda Creation-Date: 20171121 Number: 029 File-URL: https://cris.maastrichtuniversity.nl/ws/files/17289428/RM17029.pdf File-Format: application/pdf File-Size: 541780 Handle: Repec:unm:umagsb:2017029 DOI: 10.26481/umagsb.2017029