Liver Metastatic Model of Human Colon Cancer Constructed by Orthotopic Onplantation A Suitable Model for Experimental Immunochemotherapy

We have developed a liver metastatic model of human colon cancer constructed by orthotopic onplantation in nude mice. In this model, four human colon cancer strains developed liver metastases, whereas the other four did not, although extensive local growth and vessel invasion were observed in both groups. We also used this model for experimental immunochemotherapy with 5-fluorouracil (5-FU) and OK-432. 5-FU showed significant antitumor activity against the primary tumor, whereas OK-432 significantly prevented liver metastases, suggesting different chemosensitivity according to the locality of the growing tumors. Immunochemotherapy with both drugs was effective against both the primary tumor and liver metastases. This model would be useful for further study of the metastatic process and immunochemotherapy of colon cancer.