Dynamical Interactions between Multiple Cancers

Abstract

Multiple tumors in a patient have the possibility to interact with each other, through the competition for new blood supply which is required for growth and progression (angiogenesis). The multiple tumors can be independent, multiple primary cancers. Alternatively, they can be metastases which originate from one primary tumor. This paper uses mathematical models to investigate such dynamical interactions between multiple cancers. We start with a model which describes the growth of a single angiogenic tumor, and then generalize this model to include multiple tumors which compete for circulating endothelial progenitor cells in order to build new blood vessels. We explore under which conditions multiple tumors can coexist, and when one tumor can exclude other tumors from growing. Based on this framework, we discuss the circumstances under which independent multiple primary tumors can arise. We further discuss the inefficiency of metastatic cells to grow successfully, and suggest an explanation for the occurrence of multiple metastases with an unknown primary cancer.