Krebszellkinetik und Krebs-Mehrschritt-Therapie / Cancer Cell Kinetics and Cancer Multistep Therapy

Abstract

Basic to the proposed therapeutic usage of the difference in the in-vivo proliferation control between cancer and normal cells are the temporary selective increase in the proliferation rate and number of cancer cells in all kinds of tumors but without increase of the proliferative activity of normal cells. To further this aim, measurements of cellular kinetics are used, in connection with the glycolysis of different tumor tissues under saturation conditions, with the relationship between cancer cell cycle and glycolytic rate, or the local glucose level respectively, with the wide range of glucose concentrations in tumor regions which differ the conditions of supply, with the pO2-value critical for tumor growth (≈ 0.4 Torr), with the pO2-distribution in tumor tissues and the time distribution of cell cycles in human and animal cancerous tissues. From an approximative description of the cytostatic effects in different tumor regions and its validity limits it is estimated that the sensitivity towarts therapy is decreased to as low as one-tenth in poorly supplied tumor regions. These particular fractions of the tumor tissues determine the degree of tumor resistence. Additionally, from these considerations steps can be derived which could be important for multiplying the effect of the cytostatic attack on the critical tumor regions with poor supply conditions. These steps include: a) usage of combinations of cytostatic agents directed against all three sensitive phases of the cell cycle (S-G2-M); b) increase in blood glucose concentration to about 300 mg% for an optimum time span prior to the initiation of the main therapeutic process; c) increase in pO2 of the inspiration air to 320 or 400 Torr and in the degree of pO2 utilization by the use of specific pharmaceutic agents for the chosen time span preceding the main therapy; d) stimulation of tumor vascularization preceding the main therapy; e) decrease in the fraction of tumor cells utilizing glucose and O2 as a consequence of a post-therapy treatment 72 hours after the main therapy. The increase in the fraction of cells in a sensitive phase of the cell cycle is reached folowing synchronization after increasing the glucose concentration until saturation of the glycolytic capacity. Reasons are given, why the cytostatic attack has to be supplemented by other selective mechanisms which damage the tumor cell independent of the phase of the cell cycle. Such a mechanism is the lysosomal cytolytic chain reaction. Here, the death of tumor cells occurring during a sensitive phase of the cell cycle as a consequence of the cytostatic attack helps to damage cancer cells which are in the insensitive phase. A further mechanism of this kind is the immunological attack, which is also a component of multi-step cancer therapy