H. Lee Moffitt Cancer Center and Research Institute / Jan T. Poleszczuk
Abstract
It remains unclear how localized radiotherapy for cancer metastases can occasionally elicit a systemic antitumor effect, known as the abscopal effect, but historically, it has been speculated to reflect the generation of a host immunotherapeutic response. The ability to purposefully and reliably induce abscopal effects in metastatic tumors could meet many unmet clinical needs. Here, we describe a mathematical model that incorporates physiologic information about T-cell trafficking to estimate the distribution of focal therapy-activated T cells between metastatic lesions. We integrated a dynamic model of tumor-immune interactions with systemic T-cell trafficking patterns to simulate the development of metastases. In virtual case studies, we found that the dissemination of activated T cells among multiple metastatic sites is complex and not intuitively predictable. Furthermore, we show that not all metastatic sites participate in systemic immune surveillance equally, and therefore the success in triggering the abscopal effect depends, at least in part, on which metastatic site is selected for localized therapy. Moreover, simulations revealed that seeding new metastatic sites may accelerate the growth of the primary tumor, because T-cell responses are partially diverted to the developing metastases, but the removal of the primary tumor can also favor the rapid growth of preexisting metastatic lesions. Collectively, our work provides the framework to prospectively identify anatomically defined focal therapy targets that are most likely to trigger an immune-mediated abscopal response and therefore may inform personalized treatment strategies in patients with metastatic disease
Author information
Poleszczuk JT1, Luddy KA2, Prokopiou S3, Robertson-Tessi M3, Moros EG4, Fishman M5, Djeu JY6, Finkelstein SE7, Enderling H3.
1Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. jan.poleszczuk@moffitt.org.
2Department of Cancer Imaging and Metabolism, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
3Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
4Department of Cancer Imaging and Metabolism, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
5Department of GU Oncology MMG, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
6Department of Immunology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
721st Century Oncology Translational Research Consortium, Scottsdale, Arizona.