Purpose: In vitro tumor models could support the process of development of new cytotoxic drugs and selection of suitable drugs for the individual patient. We investigated whether the testing of tumor cells from patients with kidney or urinary bladder carcinoma by fluorometric microculture cytotoxicity assay (FMCA) could provide clinically relevant data for these tumor types.
Materials and methods: A total of 45 tumor samples from patients with kidney or urinary bladder carcinoma were compared with 247 samples of other tumor types with respect to sensitivity to 8 standard and 6 investigational cytotoxic drugs in the FMCA, a 72 hour assay based on the concept of total cell kill. In bladder carcinomas, sensitivity to standard drugs was correlated to various tumor characteristics.
Results: The technical success rate for kidney and bladder carcinomas was high; approximately 90% of the samples could be analyzed successfully. Kidney carcinomas were highly resistant to standard drugs and bladder carcinomas essentially as sensitive as carcinomas of the breast and ovary but with a steeper dose-response relationship. In bladder carcinoma there was no clear relationship between tumor stage, grade, ploidy, mitoses or p53 expression and drug sensitivity. Except for suramin, kidney carcinomas were poorly sensitive to the investigational drugs CdA, gemcitabine, paclitaxel, vinorelbine and topotecan. In bladder carcinomas paclitaxel, gemcitabine and suramin showed promising activity.
Conclusions: The FMCA seems suitable for cytotoxic drug sensitivity testing of urinary tract carcinomas. This technique may have a role in new drug development in these tumor types.