Vulnerability to Stress-Induced Tumor Growth Increases with Age in Rats: Role of Glucocorticoids*

Aged males rats show a delay in terminating their adrenocortical stress response and, thus, hypersecrete corticosterone during the poststress period. Because of the numerous catabolic effects of corticosterone, we hypothesized that chronic stress should induce greater pathophysiological changes in aged than in young subjects. We report that stress-induced tumor growth, associated with inoculation with fetal rats cells transformed by tumor virus, is accelerated in aged rats. Furthermore, simulation of the aged pattern of corticosterone hypersecretion in young animals using steroid administration similarly accelerates stress-induced tumor growth.