PI: Professor L.G. de Pillis, Mathematics, HMC Title: Analyzing Immunotherapy and Chemotherapy of Tumors through Mathematical Modeling Date: Summer 2003 Abstract: We develop and analyze three distinct mathematical models of tumor-immune system interactions that describe how certain types of cancer treatment affect both tumor and immune cell populations in the human body. The first of these models is a population based model that is time-dependent, and is represented by a system of ordinary differential equations. This ODE model allows us to observe creation and destruction trends in overall cell populations. The second model includes both a spatial component and a probabilistic component. With this second model we simulate nutrient diffusion and the effect of nutrient distribution on cell growth. From this model, a range of possible tumor structures can arise. The third model incoprorates geometries that allow us to investigate the macroscopic stages of tumor evolution. We deal with all models on a cellular level as well as on a macroscopic level in order to encompass various degrees of interaction and form a broader perspective. The models are validated using experimental data from published literature. Simulations that include experimental combination chemoimmunotherapies are run and analyzed. Mathematical analysis of the models is carried out. This work was done in collaboration with Professor W. Gu, Mathematics, HMC William Chang, HMC 2004 Lindsay Crowl, HMC 2004 Eric Malm, HMC 2005 Lorraine Thomas, HMC 2005 Katherine Todd-Brown, HMC 2004 Michael Vrable, HMC 2004