Novel Polypectomy System In A Preclinical Model Of Colon Cancer

Colonoscopy has been used for over a decade to monitor tumor progression in live animals. However, murine models typically have not involved routine resection of entire lesions, to parallel the clinical scenario in which polyps are observed and removed during a colonoscopy examination. A polyp resection (polypectomy) protocol was developed in the polyposis in rat colon (Pirc) model. Because a major cause of morbidity in such rodent models involves blockage of the colon, polypectomy can be used as a preventive strategy, helping to prolong the lifespan of the animal. Polypectomy in murine models opens the door to longitudinal prevention studies, and determining the molecular changes in resected tumors. A means of specifying the location of each lesion within the colon also was developed in order to track individual polyps in a temporal manner. The “PLC” classification system has three components: P, polyp number from the tail-end; L, location of the polyp from the tail-end; and C, clock face orientation of the polyp within the gut lumen. In summary, we developed a novel murine polypectomy protocol that closely parallels the human clinical scenario during a screening colonoscopy. The procedure employed the Pirc model, but it is directly applicable to longitudinal studies in other murine models of colon cancer. This work was supported by P01 grant CA090890 from the National Cancer Institute, by P30 grant ES023512 from the National Institute of Environmental Health Sciences, by the John S. Dunn Foundation, and by a Chancellor9s Research Initiative from Texas AM 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 839.