['Given the frequent inability to administer a conventional 3-weekly schedule of cisplatin to human subjects with urothelial carcinoma, we evaluated a frequent bolus metronomic schedule in a preclinical system of transitional cell carcinoma (TCC) of the urothelium. We hypothesized that the anti-angiogenic and anti-cell-migratory activity of lower concentrations of cisplatin may confer similar anti-tumor activity and demonstrate less nephrotoxicity than conventional cytotoxic concentrations.', 'We evaluated the activity of cisplatin in vitro against human urothelial carcinoma (5637) and endothelial cells (human umbilical vein endothelial cells, HUVECs). The MTT assay was employed to assess viability, and flow cytometry with Annexin-FITC labeling was employed to assess apoptosis. Cell migration in monolayer culture was assessed by scratch assay. Murine xenografts (n = 12 per group) bearing measurable subcutaneous tumors of 5637 cells were administered either no therapy, cisplatin 2 mg/kg/3 days a week (metronomic) or 6 mg/kg/ once a week (standard) intraperitoneal (i.p.) for 4 weeks. Blood was collected from 5 mice per group at baseline and at the end of therapy to measure changes in serum creatinine.', 'Significant antiproliferative activity, but poor pro-apoptotic activity, was observed against 5637 urothelial carcinoma cells in vitro by MTT assay with cisplatin at concentrations lower than those attainable in vivo. Anti-proliferative activity against HUVECs required higher concentrations than attainable in vivo. Anti-migratory activity was observed against 5637 and HUVECs at earlier time points and with concentrations lower than anti-proliferative concentrations. In murine 5637 xenografts, standard cisplatin was significantly better at inhibiting tumor growth than the no treatment control (P = 0.005), while metronomic therapy was not better than control (P = 0.22). Standard cisplatin was also significantly nephrotoxic (P = 0.016), while metronomic cisplatin (P = 0.374) or no therapy (P = 0.178) did not demonstrate significant nephrotoxicity compared with baseline.'] Is a conventional preclinical schedule of cisplatin more effective than a metronomic frequent bolus schedule for urothelial carcinoma?