Influence of tumor site on the therapy of murine kidney cancer

Objective: The purpose of this study was to evaluate the influence of tumor site on the therapy of an experimental murine kidney cancer model, Ranca. Methods: Equal number of tumor cells were injected subcutaneously, intraperitoneally, sub-renal capsule, and intravenously to induce tumors. The animals were then assessed for growth of the primary tumor, metastases and survival. Immunohistochemistry and flow cytometry was performed to identify the phenotype of infiltrating lymphocytes. Tumor bearing animals were treated with high dose interleukin-2 or whole body radiation, and response of the primary tumors as well as the metastases was assessed. Results: Renca tumors grew well regardless of the methods of induction. Spontaneous metastasis could be best induced in the sub-renal capsule model. More consistent numbers of pulmonary metastases were obtained by intravenous injection of the tumor cells. Immunotherapy was able to reduce the size of the primary tumor as well as the number of metastasis. Whole body radiation caused some reduction in the primary tumor but did not have a major effect in reducing metastasis. Conclusions: The Renca model is a suitable animal model to study the response to different therapeutic interventions. The site of the tumor growth is not a significant variable in the response to treatment.