Paper Title
A Mathematical Model for Chaotic Cancer Evolution

Abstract
It is well accepted that cancer evolution is chaotic. However in literature serious mathematical proofs or other theoretic verifications are still lacking. In this paper, we present a mathematical model for the cancer evolution and prove that cancer evolution is chaotic in the sense of Devaney. We also discuss the Lyapunov exponent for this chaotic system and present an estimation of the maximal Lyapunov exponent. This quantity estimation may have potential implication in cancer treatment.