A Stochastic Interacting Particle-Field Algorithm for a Haptotaxis Advection-Diffusion System Modeling Cancer Cell Invasion
Boyi Hu, Zhongjian Wang, Jack Xin, Zhiwen Zhang
TL;DR
This work develops a stochastic interacting particle-field (SIPF) algorithm to simulate cancer cell invasion within a haptotaxis advection-diffusion (HAD) system, using a particle representation for cell density and a spectrally discretized ECM field solved by FFT-based methods. The method updates the MDE field implicitly via a Green’s-function kernel, the ECM field explicitly in Fourier space, and the cell density through Euler–Maruyama dynamics driven by the ECM gradient, yielding a mesh-free, low-cost, and self-adaptive solver that handles nearly singular free-boundary phenomena in 3D. The authors establish global well-posedness results for the HAD system and derive integral identities that facilitate validation of numerical approximations. Numerical experiments show SIPF outperforms finite-difference and spectral methods in 3D, especially for small diffusion, and remain stable under challenging conditions such as multiple clusters and reduced diffusion, highlighting its potential for realistic tumor invasion modeling and future extensions toward oxygen-coupled and multi-species haptotaxis models.
Abstract
The investigation of tumor invasion and metastasis dynamics is crucial for advancements in cancer biology and treatment. Many mathematical models have been developed to study the invasion of host tissue by tumor cells. In this paper, we develop a novel stochastic interacting particle-field (SIPF) algorithm that accurately simulates the cancer cell invasion process within the haptotaxis advection-diffusion (HAD) system. Our approach approximates solutions using empirical measures of particle interactions, combined with a smoother field variable - the extracellular matrix concentration (ECM) - computed by the spectral method. We derive a one-step time recursion for both the positions of stochastic particles and the field variable using the implicit Euler discretization, which is based on the explicit Green's function of an elliptic operator characterized by the Laplacian minus a positive constant. Our numerical experiments demonstrate the superior performance of the proposed algorithm, especially in computing cancer cell growth with thin free boundaries in three-dimensional (3D) space. Numerical results show that the SIPF algorithm is mesh-free, self-adaptive, and low-cost. Moreover, it is more accurate and efficient than traditional numerical techniques such as the finite difference method (FDM) and spectral methods.
