In vitro chemosensitivity assay of human urologic malignancies

An attempt was made to detect the chemosensitivity of fresh specimens of urologic malignancies using a liquid medium culture assay and an agar cloning assay. The sensitivity of cells to anticancer drugs was divided into five grades according to the ratio of cytotoxicity: 0 (0%); 1 (1-25%); 2 (26-50%); 3 (51-75%), and 4 (76-100%). Among the urothelial cancers (36 cases), the sensitivity grade was on the average 2.05 with cisplatin, 2.11 with doxorubicin, 1.49 with endoxan, 1.46 with methotrexate and 1.79 with thiotepa. Higher grade tumor specimens have higher sensitivity to anticancer drugs than lower grade tumor specimens, but there was no correlation between clinical stages and drug sensitivity. Three of 36 cases (8.3%) of transitional cell carcinoma showed complete drug resistance. Simultaneous agar culture clonogenic assays were performed in 7 cases, the results of which were similar to those of the liquid culture method. Three major drawbacks of clonogenic assay are that it is time-consuming, difficult to count, and easy to contaminate. Among 16 cases of kidney tumors, the highest response rate was to thiotepa (2.0) and lowest to endoxan (1.4). No correlation between clinical stage and drug sensitivity could be found. The other five miscellaneous cases all demonstrated moderate sensitivity to those anticancer drugs.