The Effects of Reduction in Food Intake on Growth and Differentiation of a Squamous-Celled Carcinoma in Mice, with Special Reference to Experimental Chemotherapy

Abstract

THE inhibitory effect of a reduction in body weight on tumour genesis and growth in experimental animals has been studied for some years. A reduction in caloric intake has been shown to inhibit the growth of Sarcoma 180 in mice (Bischoff and Long, 1938). Variations in the constituents of the diet have shown that a reduction in fat or protein has no inhibitory effect, and variations in vitamin content have produced a diversity of results with few instances of any inhibitory effects. This literature has been comprehensively summarised by Tannenbaum and Silverstone (1953). Complete regressions were rare (Tannenbaum, 1940) and Tannenbaum and Silverstone (1953) stated that underfeeding or caloric restriction did not appear to be a successful means of controlling the growth of tumours. Barvick and Goodson (1954) showed that food restriction for 24 to 48 hour periods produced no significant inhibition of Sarcoma 180, and in mice on total starvation the tumour sizes at death (5 days) were one-third that of the controls.The present study, with a squamous-celled carcinoma in mice, shows a high proportion of regressions resulting from underfeeding, and relates the effect to the degree of differentiation of the tumour. MATERIALS AND METHODSThe tumour used in this study was a homologous squamous-celled carcinoma in RIII strain mice. Sarcoma 37 in RIII strain mice was also used in a few parallel experiments. The mice used in each experiment were inoculated subcutaneously in the right flank with portions about 1 mm3. taken from the cortex of one parent tumour. The transplants became measurable (about 18 mm.2) about seven days after implantation, and were then divided into two groups-each group containing at least ten mice. The control group received water and diet 41* ad lib., the treated group received water ad lib. and a proportion of the estimated normal consumption of diet 41. It was found that 2 g. per day for each female and 3 g. per day for each male mouse resulted in a loss in body weight of from 20 to 25 per cent. This degree of starvation was the maximum attempted in this series of experiments. The mice in both groups were kept four or five to a cage; the individual weight variations were found to be consistent throughout the groups, consequently no attempt was made to use individual cages.* The percentage composition of diet 41 (Bruce, 1950) is as follows: Wholemeal flour 46, ground oats 40, white fish meal 8, dried yeast 1, dried skimmed milk 3, cod-liver oil 1, sodium chloride 1.

Ethanol, 30 Per Cent, and Hamster Pouch Carcinogenesis

“…The importance of this problem to the interpretation of the results of the present experiment becomes evident when we consider that a decreased caloric intake has been proven to delay the onset and diminish the incidence of experimentally induced tumors. [24][25][26][27][28][29] A question arose regarding the accuracy of the use of a brush for the delivery of an identical quantity of the agent to each pouch at each application, although Morris'0 has suggested that his study of this problem revealed the brush method to be surprisingly accurate. Poel and Kammer" have described a method in which the agent is delivered in a dropwise fashion from a tuberculin syringe, on which is mounted a blunted, 15-gauge needle.…”