Doctors are well aware that sometimes cancer treatments not only fail, but even work backwards, i.e. they make the treated tumor grow. In this work we present a mathematical perspective on this paradox in the case of chemotherapy, by studying a minimally parameterized mathematical model for the system composed of the tumor and the surrounding vasculature. To this end, we will use a system of two well-established nonlinear ordinary differential equations, which incorporates the cytotoxic (via the Norton-Simon hypothesis) and antiangiogenic effects of chemotherapy. Finally, we provide two theoretical ways to avoid these anomalies.
@article{arxiv.2503.10670,
title = {A mathematical perspective on the paradox that chemotherapy sometimes works backwards},
author = {Luis A. Fernández and Isabel Lasheras and Cecilia Pola},
journal= {arXiv preprint arXiv:2503.10670},
year = {2025}
}