Treatment of mice bearing a Krebs ascitic tumor by means of a protocol based on radioactive copper (64Cu). III. Efficiency of the anticancer treatment according to the stage of tumor development.

The treatment described previously (Anticancer Res 9:947-954,1989) was efficient when applied on day 1 or 6 after the injection of 5 x 10(5) Krebs ascitic cells in mice. Under our experimental conditions, all the untreated mice died within 12 to 25 days. The experiments described show that the treatment developed, is efficient when applied on day 11 but not on day 16. To understand the difference in the treatment efficiency between these two days, we tested the 64Cu incorporation inside the ascitic cells. It was observed that 64Cu incorporation exists on day 11 but no longer on day 16. On day 16, the inefficiency of the treatment must be correlated with the non-incorporation of 64Cu inside the ascitic cells. As the tumor growth is also arrested on day 16, an irreversible stage is reached. A model was developed to explain the results obtained. In this model, cancer develops in 3 successive stages. In the first stage, the cellular functioning is under the control of the malignant tumor cells and the number of cells with the "cancer functioning" is increasing with time, but decreasing after removal of the malignant tumor; in the second stage, tumor and cancer both develop independently, meaning that the number of cells with the "cancer functioning" will continue to increase after the removal of the malignant tumor; in the third stage, each cell of the organism has the "cancer functioning" and the characteristics of malignancy will by retroaction.