Once diagnosed, cancer requires a fast, inexpensive and reliable assessment of the current state and potential progression of the disease. A new method for estimating tumor cell diffusivity 𝐷 and proliferation rate 𝛾 from single-point-in-time routine biopsies aims to deliver just that, and the ratio of its estimates 𝐷/𝛾 is a promising candidate for a new biomarker for risk-stratification in radiotherapy. Here, we extend the findings of the researchers at MD Anderson Cancer Center [1]<https://ecmtb2026.org/contributions/ms71-12#ref-Pasetto-2024>, who developed the method, by providing a simulation-based validation. The method is applied to in silico biopsies which are generated by solving the three-dimensional reaction-diffusion (RD) equation for different growth terms (exponential and logistic) with a Dirac-Delta initial condition, and transforming the continuous results into spatial point patterns via a form of reverse coarse-graining. References: [1] Pasetto, S., Montejo, M., Zahid, M. U., Rosa, M., Gatenby, R., Schlicke, P., Diaz, R., & Enderling, H. (2024). Calibrating tumor growth and invasion parameters with spectral spatial analysis of cancer biopsy tissues. Npj Systems Biology and Applications, 10(1), 1–9. https://doi.org/10.1038/s41540-024-00439-0 ----- -