A Novel Non-Invasive Epithelial Ovarian Cancer Mouse Model Of Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

Abstract

Background: Hyperthermic intraperitoneal chemotherapy (HIPEC) in combination with interval cytoreductive surgery increases the overall survival of epithelial ovarian cancer (EOC) patients with advanced disease. Despite its proven benefits, the mechanism by which HIPEC extends overall survival remains unknown and current strategies to optimize HIPEC are therefore limited. A major challenge is the lack of a robust and streamlined model to investigate the mechanisms underlying HIPEC efficacy. Objective: To introduce a novel murine model that can be used to enhance our understanding of HIPEC therapy. Method: ID8-luc, an EOC mouse cell line, is inoculated into immunocompetent C57BL/6J mice intraperitoneally. Once tumor is detected by In Vivo Imaging System (IVIS), cisplatin (5 mg/kg) is injected intraperitoneally and superficial hyperthermia of 40C is applied to the animals abdomen and pelvis using an FDA-approved hyperthermia unit (BSD500) for 20 minutes. To validate the model, four treatment conditions were tested: cisplatin and hyperthermia, cisplatin and normothermia, vehicle and hyperthermia, and vehicle and normothermia. Tumor growth was assessed over the course of treatment using IVIS optical spectrum. Results: Tumor growth in mice treated with hyperthermic cisplatin was significantly suppressed compared to mice treated with normothermic cisplatin (p < 0.05). No significant differences in tumor growth were observed in the hyperthermic vehicle and normothermic vehicle groups. Conclusions: We developed an innovative noninvasive mouse model of HIPEC. Similar to patients with advanced ovarian cancer who are treated with HIPEC at the time of interval cytoreductive surgery, our model demonstrates that hyperthermia enhances the inhibitory effect of cisplatin on intraperitoneal tumor growth. Development of this murine model provides an opportunity to elucidate the mechanisms underlying HIPEC and offer an opportunity to test adjunct treatments in a pre-clinical setting to enhance the utility of HIPEC.