The anticancer activity of
melphalan and
N-(2-chloroethyl)-N-nitrosocarbamoyl-omega-lysine (
CNC-omega-Lys), was compared in the autochthonous,
methylnitrosourea-induced mammary
carcinoma of the Sprague-Dawley rat. In addition, the influence on the therapeutic efficacy of the combination with
diazoxide, causing a mild, reversible diabetes, and with
insulin was investigated. The comparison of
melphalan and
CNC-omega-Lys clearly showed the superiority of
melphalan. Both compounds displayed a significant tumour inhibition in their medium and the highest dosages in comparison to the untreated control. The combination with
diazoxide resulted for almost all groups in an increased tumour inhibition. Only the lowest dose of
CNC-omega-Lys +
diazoxide did not reduce the tumour volume significantly versus the control group. The combination with
insulin, however, resulted in a loss of tumour inhibition compared to the effect of the cytotoxic
drug alone, although in these groups, too, a significant decrease of tumour volumes versus controls could be observed. Mortality was within tolerable limits (less than 20%) through the treatment period for all experimental groups. Median lifespans were increased in all
therapy groups, but no additional benefit could be observed in the combination treatment groups.