Lethal toxicity of cyclophosphamide depends on the tumor stage. Studies on the syngeneic adenocarcinoma EO 771 in C57bl/6j mice.
The effect of tumor size and tumor age on the efficiency, and particularly on the lethal toxicity, of a single application of cyclophosphamide (300 micrograms/g body weight i.p.) to C57bl/6j mice bearing the adenocarcinoma EO 771 has been investigated by treating tumors of the same size but different age on the one hand and tumors of the same age but different size on the other. Treatment of animals bearing larger tumors is consistently associated with increased toxicity: 71/74 animals with tumors > 1.25 g at the time of treatment die of toxicity as opposed to only 1/33 animals with tumors < 1.25 g (relative risk of death of toxicity is 31.7 for animals with tumors > 1.25 g as compared to those bearing tumors < 1.25 g). On the contrary, the age of the tumor does not appreciably influence the toxicity of treatment. The reason for the increased toxicity of the antineoplastic chemotherapy with increasing tumor size is not clear. However, the rather abrupt manifestation of lethal toxicity as a function of tumor size coincides well with the beginning of tumor cachexia in the same animals. Possible mechanisms for this interrelationship of cachexia and potentiation of treatment toxicity are discussed.
Bassukas
I D
ID
Institut für Medizinische Strahlenkunde, Universität Würzburg, Germany.
Maurer-Schultze
B
B
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D000818:Animals; D002100:Cachexia / Q000150:complications; D003520:Cyclophosphamide / Q000494:pharmacology*; D008297:Male; D015674:Mammary Neoplasms, Animal / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009367:Neoplasm Staging; D009929:Organ Size / Q000187:drug effects
D003520:Cyclophosphamide