Effect of Repeated Brief Stress on Growth of Ehrlich Carcinoma in the Mouse2

Abstract

These investigations were directed to the development of stressor systems for the production and maintenance of emotional disturbance in mice, and the application of these stressors to mice, in order to explore their effect on the growth rate of malignancies. In a series of 8 experiments, mice with subcutaneous Ehrlich tumor transplants were subjected to stress either by an avoidance shuttlebox or by confinement. In 5 of the 8 experiments significantly smaller tumors were found in stressed animals as compared to their controls. Two of the remaining 3 experiments yielded nonsignificant results in the same direction, and 1 showed a significant increase in the size of tumors. Exposure to shuttlebox or confinement stress tends to inhibit the growth of Ehrlich tumors in mice, and it is suggested that stress represents a variable to be considered in cancer research. Stress also offers an additional context for the exploration of tumor-host interrelationships.