Possible mechanism of the selectivity of the cytostatic action of antineoplastic preparations.

A model of the phenomenon of selectivity of antineoplastic phase-specific preparations in leukemia, based on the assumption that any proliferating cells are equally sensitive to the action of such preparations, is suggested. Therefore, selectivity, the concept and fundamental significance of which were formulated and substantiated by the authors earlier, can be expressed in terms of the proliferative pathways of the normal and leukemic populations, the ratio between which thus plays the deciding role in the selection of the optimum system of therapy. The concept of maximum selectivity, which is a convenient numerical characteristic of a preparation, was introduced. A comparative quantitative analysis was made of a number of antineoplastic preparations (vinblastine, vincristine, amethopterin, arabinosylcytosine, azaserine); it showed that the conclusions of the model do not contradict the experimental data.