[Comparative study of the cytotoxic effects of anthracycline antibiotics on heterotransplants of human breast cancer cultivated in diffusion chambers in vivo].

Cytotoxic activity of doxorubicin, daunomycin, carminomycin and ruboxyl against 50 human breast cancer heterotransplants in diffusion chambers was studied. The effect was estimated autoradiographically on the 6th or the 7th day of the cultivation after the drug administration in the maximum tolerance doses. The tumors were considered sensitive when the labeling index of their transplants after the treatment appeared to be reduced by 50 or less per cent against the control. The number of the tumors sensitive to all the drugs amounted to 72-80 per cent. 19 tumors were sensitive to 4 antibiotics. 14 and 8 tumors were sensitive to 3 and 2 antibiotics, respectively, and only 1 tumor was sensitive to 1 drug. The sensitivity significantly correlated with the initial labeling index of the primary tumors and their heterotransplants. The results suggested that daunomycin and ruboxyl possessed a high cytotoxic activity close to that of doxorubicin and carminomycin and might be recommended for clinical trials in the treatment of patients with breast cancer.