The effects of anti-cancer drugs on body weight, regional brain weights, organ weights and the concentrations of putrescine, spermidine and spermine in the prostate, seminal vesicles, testis, thymus, spleen, kidney, heart, liver, small intestine, large intestine, stomach, tongue, skeletal muscle, lung, cerebellum, hippocampus, corpus striatum, cortex, combined thalamus and hypothalamus, and diencephalon of the brain, were examined in rats that had been given the drug for five consecutive days. Drugs that reduce polyamines that are associated with tumor cell growth seem to be a good choice for management of tumors in tissues and organs of the body and regional tissues of the brain, but drugs that increase some polyamines in the specific tissues or organ and regional tissues of the brain of the rats are not because they stimulate the growth of the tumor cells.