Interactions of radiation and cancer chemotherapeutic drugs in a C3H mouse mammary carcinoma.
The interactions of radiation and adriamycin (ADM), bleomycin (BLM), cyclophosphamide (CTX), 5-fluorouracil (5-FU), methotrexate (MTX), mitomycin C (MM-C), or cis-diamminedichloroplatinum II (cis-DDP) were studied in a spontaneously arisen C3H mouse mammary carcinoma. The tumour response to drugs alone was evaluated by measuring the tumour to reach a volume 5 times that of the treatment day. CTX resulted in a marked tumour growth delay whereas the other drugs had a modest or uncertain effect. In the combined treatment experiments, drugs were administered as single doses either 15 min before or 4 hours after graded single doses of irradiation. The end point for each treatment was the radiation dose which on an average was required to achieve local tumour control in 50 per cent of the mice (TCD50). The dose effect factor (DEF) was 1.16 for ADM and 1.17 for CTX, the enhanced radiation response being independent of administration before or after irradiation. MM-C also decreased the TCD50 for radiation alone, but its effect was more marked 15 min before (DEF 1.32) than 4 hours after irradiation (DEF 1.18). BLM, 5-FU, MTX, and cis-DDP had no effect on the radiation response neither when administered 15 min before nor 4 hours after irradiation.
von der Maase
H
H
Overgaard
J
J
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000628:therapy*; D051379:Mice; D008809:Mice, Inbred C3H; D011879:Radiotherapy Dosage