Here we describe a finite element model of the mechanical stresses and strains involved in the growth and development of epithelial cancers, specifically pancreatic ductal adenocarcinoma (PDAC). We model a growing tumor swelling over time, modeled as fluid influx in response to changing solute concentrations. Stresses and strains are computed in surrounding material regions in response to this swelling. Further studies are conducted into the relative impacts of factors such as basement membrane thickness, stiffness, and duct radius. We observe that normal stresses are confined mostly to the basement membrane layer and hypothesize that there exists some threshold for axial stress beyond which the basement membrane ruptures and cancer is able to invade into the surrounding tissue.