NB rat bladder cancer model: evaluation of the subrenal capsular assay system.

Since 1978 this laboratory unit has evaluated the Nb rat prostate adenocarcinoma model. More recently, over a 15-month period we have studied the Nb rat number one bladder tumor, a spontaneously appearing tumor in an aged female noble rat. Initial chemotherapeutic experiments have been carried out, revealing activity of this tumor to cyclophosphamide. Herein we report the feasibility of utilizing the subrenal capsular assay in the model. The advantage of this system is that one is able to determine the effect of chemotherapy in a very short time, i.e., 7 days. This method may save considerable expense and may serve as a useful projector for potential future chemotherapeutic trials of bladder cancer. In this assay system, cyclophosphamide, adriamycin, and cis-platinum and methotrexate did result in a significant decrease in tumor volume change. This change paralleled the results that we had seen in the past from the use of chemotherapy with cyclophosphamide alone in treatment of subcutaneous tumor nodules of bladder carcinoma. Further exploration of this method is warranted from a time efficiency as well as from a cost standpoint.