Chemotherapy and human bladder carcinoma transplanted into NMRI nu/nu mice.

Transitional and squamous-cell carcinomas of the bladder that were transplanted and successfully retransplanted in further passages to NMRI nu/nu mice were used to test the efficacy of chemotherapy. Mitomycin and bleomycin consistently retarded tumor growth; results with platinex and methotrexate were variable. Combination therapy was not much better than single-drug therapy. Substances that proved effective in the mouse model produced some response in the corresponding patients in a series of patients on specific chemotherapy. In a previous study we have shown that tumor growth of transplanted human bladder carcinoma accelerates, unlike transplanted renal cell carcinoma when successfully subpassaged, resulting in a uniformly fast growing rate similar in all transplanted tumors including those which initially started with slow growing rates. Most importantly, however, tests in a given tumor conducted on a slow-growing early passage and on a fast-growing late passage produced different results. We concluded that this finding might explain the clinical observation that tumor remission due to chemotherapy in patients with metastatic bladder carcinoma does not last very long and seldom prolongs survival. It is assumed--it is not proved--that substances that proved effective in fast growing passages are probably likely to yield greater prolongation of life than those effective in slow-growing passages.