Cancer as a Chronic Disease with which Human can Coexist

Abstract

The aim of the current study is to establish new physical tumor-markers for the effectiveness of the cancer therapy upon which human can coexist with cancer as a chronic disease. Doubling Time-Energy Conversion (DT-EC) during tumor formation and cancer therapy were investigated in groups of mice i.p. injected with (1x106) HeyA8 MDR cells and (2.5x105) HeyA8 cells, and treated by cell cycle specific drug (docetaxel) one week after tumor cell injection. Therapy for HeyA8 tumor model consisted of three groups: (a) Phosphate Buffered Saline (PBS), (b) Maximum Tolerated Dose (MTD) for Docetaxel (15 mg/kg every 2 weeks), (c) metronomic Docetaxel (0.5 mg/kg thrice weekly). Therapy for HeyA8 MDR tumor model consisted of two groups: (a) PBS, (b) MTD Docetaxel (15 mg/kg every 2 weeks) Mice were monitored for adverse effects and tumors were harvested after 3 to 4 weeks of therapy. Tumor of advanced stage (HeyA8 MDR model) was characterized by higher rate (1st derivative) of DT-EC (with respect to the doubling time) and faster deceleration (2nd derivative) of DT-EC (with respect to the doubling time). Energies yield by equivalent doses with same regimen (MTD) in both tumor models were identical regardless to tumor size or resistance. Metronomic regimen was more effective than the standard one in HeyA8 model. Despite the dose of the metronomic regimen (147μ g/mL) was about one fifth of that of the MTD of the standard one (840μ g/mL) the energy yield by the smaller dose was greater than that yield by the higher one with more reduction in the rate of DT-EC and more slowing for the DT-EC deceleration. Thus the effectiveness of the cancer therapy is assessed by how much the 1st derivative of DT-EC has been minimized and by how much the 2nd derivative of DT-EC has been slowed down to treat cancer as a chronic disease with which human can coexist as long as possible.