A mouse breast cancer cryoablation model: leveraging cryoablation for high-risk BC - from the bench to the clinic 3755

Abstract Description Triple-Negative Breast Cancer (TNBC) remains a challenge to treat with metastasis being the leading cause of death. The mainstay of treatment is chemo-immunotherapy followed by resection. BC cryoablation, studied as a less invasive approach, has the advantage of augmenting anti-tumor immune responses. Cryoablation deep-freezes the tumor - killing it, while preserving cancer antigens that can educate T cells to recognize and destroy cancer cells at distant sites, known as the “abscopal effect, which may decrease tumor recurrence/metastasis for TNBC patients. Studying the immune response to cancer therapies requires immune competent animal models with compatible tumor cell lines for translational research to the clinic. To determine safety and immunological efficacy of cryoablation for TNBC, we developed a BALB/c-4T1 mouse model to study the local and systemic immune effects of cryoablation. Mice were transplanted bilaterally with 4T1-luc TNBC cells in the mammary fat pad whereby luciferase bioluminescence allowed in vivo imaging of the tumor; 2 weeks later, left tumors were cryoablated. We found full destruction of cryoablated tumors after 24 h, increased immune cell infiltration in local and distant tumors after 1 week, and reabsorption of the cryoablated tumors at 6 weeks. These results demonstrate the utility of the model to evaluate the immune abscopal effect and future application investigating cryoablation with immune checkpoint inhibitors for designing clinical trials. Funding Sources Supported by a the CH Foundation and ASCO Equipment endowment to Excellence in Women’s Health, TTUHSC. Topic Categories Translational and Interventional Immunology (TI)