Dietary Protein and Tumor-Host Relationship in the Rat

Abstract

The time for the establishment of a transplanted sarcoma in the rat was at a minimum in animals fed 12% of casein. Supplementing 12% of casein with 0.67% of DL-methionine, or increasing the casein content of the diet to 25 or 35% lengthened this induction period. However, the rate of growth of the tumor after it was established was the same on all diets. Feeding the methionine-supplemented diet or the high-casein diet favored the development of the carcass of the tumor-bearing rat, thereby reducing the depleting effect of the growing tumor. N, N′, N′′-triethylenephosphoramide reduced the development of both tumor and carcass; food utilization by the carcass was also reduced in the presence of this drug. Supplementing 12% of casein with methionine, or feeding high protein diets, favored the development of the carcass in the presence of TEPA, resulting in a more favorable condition for long survival time and regression of the tumor.