Evaluation of chemotherapeutic responsiveness in Nb rat prostate cancer model. 5-fluorouracil, methotrexate, cyclophosphamide, and adriamycin.

We elevated four chemotherapeutic agents in 105 male Nb rats with transplanted Nb rat prostatic tumors. Tumor volume and the presence or absence of metastasis were determined at the completion of the experiment and served as indicators of agent effectiveness. 5-Fluorouracil and cyclophosphamide were the most effective agents (P < 0.01). Seven of ten animals treated with cyclophosphamide had complete tumor regression; only one had pulmonary visceral or mediastinal metastasis. In other chemotherapeutic and control groups, no animal had complete tumor regression and approximately 50% of the experimental animals developed metastases despite chemotherapy. Final tumor volume was significantly reduced when compared to controls in the high-dose methotrexate doxorubicin hydrochloride (Adriamycin), cyclophosphamide, and both 5-fluorouracil groups (P < 0.01).