Organoids as preclinical models to improve intraperitoneal chemotherapy effectiveness for colorectal cancer patients with peritoneal metastases: Preclinical models to improve HIPEC

Background Peritoneal metastases (PM), corresponding to tumor implants into the peritoneal cavity, are associated with impaired prognosis and low responsiveness to systemic chemotherapy. A new therapeutic approach has dramatically changed the prognosis of patients with PM from colorectal cancer (CRC), consisting in the association of a complete cytoreductive surgery followed by intraperitoneal chemotherapy associated to hyperthermia (HIPEC). Many drugs have been administered intraperitoneally, but no clear consensus has been approved. Therefore, relevant preclinical models are essentials for the efficient translation of treatments option into affected patients. Method Organoids, the last generation of preclinical models, were used to rationalize and improve intraperitoneal chemotherapy. We tested several cytotoxics, combination, effect of hyperthermia, exposure duration and frequency. Results Organoids were a representative model of response to chemotherapies used for the treatment of PM from CRC; 460 mg/m² of oxaliplatin being the most efficient cytotoxic treatment. Repeated incubations with oxaliplatin; mimicking cycles of intraperitoneal treatment, resulted in an increased efficacy. Conclusion & discussion Organoids are relevant models to study the chemosensitivity of peritoneal metastases from CRCs. These models could be used for large scale drug screening strategies or personalized medicine, for colorectal carcinoma but also for PM from other origins.