Effect of generalized hypothermia on normothermic tumors

Abstract

All attempts to decrease or to stop the growth of tumors by hypothermia have failed up to now. A new approach to this problem was attempted here, i. e., the use of generalized body cooling to withdraw the metabolic support for normo-thermically maintained tumors. For this purpose the bodies of 107 hamsters were cooled to a temperature of 4 C during a period of 10 hr. while the tumors (Toolan H. A. No. 1U) remained uncooled at 37 C. The cheek pouch with the tumor was kept at a temperature of 37 C by an electrical "heating device" and a thermostat servo-mechanism. After the treatment the tumors regressed and disappeared completely without resuming their growth afterward. The histological examination shows that the process of disappearance of tumor cells is a slow one, lasting 10-15 days, and that the changes observed are similar to changes induced by ischemia. While tumor cells shrink and die the muscle cells of the cheek pouch after the treatment undergo chronic inflammation and degenerative changes. Several weeks later, however, the recuperation of the cheek pouch is fully completed.