Adverse effect of cyclophosphamide at moderate dose in combination with standard drugs on intraperitoneally implanted Lewis lung carcinoma in mice.
Adverse (tumor-enhancing) effects of cyclophosphamide at moderate dose (50 mg/kg) given therapeutically were confirmed on the intraperitoneally implanted Lewis lung carcinoma (LLC) in allogeneic DBA/2 and BALB/c mice. It was recently demonstrated that antitumor effects of five standard drugs (actinomycin D, adriamycin, BCNU, 5-fluorouracil and methotrexate) were abolished or diminished when cyclophosphamide (50 mg/kg) was therapeutically combined with such drugs against intraperitoneally implanted LLC both in syngeneic C56BL/6 and allogeneic DBA/2 and BALB/c mice, while the effects of three drugs (cis-diamminedichloroplatinum, 5-thioguanine and vincristine) were not affected by the cyclophosphamide therapy. It is suggested that cyclophosphamide therapy at adjusted lower doses in man might not only be effective but also have a risk to enhance tumor growth and diminish the beneficial effects of other drugs in combination chemotherapy.
D000818:Animals; D000970:Antineoplastic Agents / Q000037:antagonists & inhibitors*; D003520:Cyclophosphamide / Q000008:administration & dosage* / Q000627:therapeutic use; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation
D000970:Antineoplastic Agents; D003520:Cyclophosphamide