Tar Cancer in Mice Maintained on Diets Supplemented with Fresh Liver

Abstract

During the years 1927–1932 studies on the nutritional aspects of tar cancer were carried out at the University Field Laboratories, Sheffield, under the general supervision of Professor E. Mellanby, F.R.S. A brief summary of these studies was published in the Annual Report of the Yorkshire Council of the British Empire Cancer Campaign for 1931–1932. In the main it was found that any foodstuff whose inclusion in the basal diet improved the general condition of the animals as shown by their appearance, increased life spans and rates of growth, also produced the same effect on the rates of growth of the benign and malignant tissues. Conversely, any food supplement which adversely affected the general condition of the animals decreased the rates of growth of the tumours. Ox liver, however, was found to occupy an anomalous position in this respect. In the early stages of the studies it was found that the addition of fresh ox liver to a basal diet of bread, Sussex oats, cabbage, and water, materially accelerated the rate at which skin warts appeared in mice treated with a coal tar, A. The warts appeared earlier and in a greater number of animals than in a similar group maintained on the basal diet only. The difference between the reaction of the two groups was large enough to be significant, but, to put the matter beyond doubt, two further experiments were carried out with another coal tar, D, and its dilution product in glycerol. In both these experiments, however, no appreciable acceleration of tumour production in the case of the mice fed on the liver-supplemented diets could be detected. At this stage of the studies Maisin and Francois (1928) published results in which they stated they had observed an acceleration of tumour production when they supplemented a basal diet two or three times a week with liver. Although they used a smaller number of animals, their results agreed in the main with those found in the above studies with the first tar, A.