title: [Comparison of a continuous infusion with a daily bolus injection of bleomycin in a heterotransplanted human testicular cancer].
abstract: Continuous Infusion vs. Bolus Injection of Bleomycin in a Human Testicular Cancer Xenograft System Bleomycin ( Bleomycinum Mack ) ranks among the most effective agents against non-seminomatous testicular cancer. The cytocidal effects of this drug are cell cycle dependent and increase with duration of exposure. Schedule dependency has been demonstrated in conventional murine tumor systems and recently superiority of continuous infusion over bolus injection has been claimed using the "Lewis lung carcinoma". The continuous infusion of bleomycin has found entry into many successful combination chemotherapy regimens without definitive proof of its superiority by a randomized clinical phase II trial. Presently, however, any clinical study comparing single agent activity in untreated patients with testicular cancer would meet ethical restrictions since combination chemotherapy affords cures in 30-80% of all cases. The human tumor xenograft model employing congenitally athymic (nu/nu) mice preserves salient features of the original tumor specimen with remarkable fidelity. Thus structural similarity at the microscopic level ("embryonal carcinoma with choriocarcinoma") and production of beta-HCG both in the donor patient and the subsequent xenograft line "Ma" could be demonstrated. The overall correlation between serum beta-HCG levels and tumor volumes was significantly positive (r = 0.85; p = 0.001), but varied among individual tumor-bearing mice. Covering a total dose range from 10.5-42 mg/kg given over 7 days no difference was found between daily bolus injections and continuous infusion of bleomycin. These data allow for the first time a direct comparison of both schedules of administration in a testicular cancer of human origin. On the basis of these findings the clinical preference for continuous administration of bleomycin is questioned, especially since it may cause considerable discomfort to the cancer patient.
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D007263:Infusions, Parenteral; D007275:Injections, Intravenous; D008297:Male; D051379:Mice; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D013736:Testicular Neoplasms / Q000188:drug therapy*; D013997:Time Factors; D014183:Transplantation, Heterologous
chemical_list: D001761:Bleomycin
vernacular_title: Vergleich einer Bleomycin-Dauerinfusion mit der täglichen Stossinjektion an einem heterotransplantierten menschlichen Hodenkarzinom.