Extinction and persistence of a stochastic tumor-normal-immune model with periodically pulsed chemotherapy treatment.

Abstract

In this paper, we introduced a stochastic tumor-normal-immune dynamical system with periodically pulsed chemotherapy to investigate the impact of environmental noise on tumor evolution. By utilizing theorems from impulsive stochastic differential equations, we analyzed tumor-free and globally positive solutions within the proposed framework. Our findings demonstrated that the expected solutions remained bounded. Additionally, we derived sufficient conditions for various tumor outcomes, including extinction, non-persistence in the mean, weak persistence in the mean, and stochastic persistence. Finally, we validated our results through comprehensive computer simulations.