Natural History of Various Tumors Implanted on the Feet of Mice

MUller (5), that some human tumors could be selectively destroyed by prolonged heating at temperatures below 55°C. and that the effects of irradiation were potentiated by heating. Between 1921 and 1955 Rhodenburgand Prime (6), Wester mark (10), and Warren (9) published studies on the effects of heat and of heat combined with radiation on tumors of animals and of man. Since 1955 little significant work has been published on the reaction of tumors and normal tissues to pro longed exposures to temperatures between 42°C. and 55°C. In 1958, Selawry, Carbon, and Moore (8) pub lished a review of the world's literature on the response of tumors to ionizing rays at elevated temperatures, and in 1961 I published a report on the biologic effects of heat (1), concluding that: “1. Some cancers, in both man and animals, are moresusceptible todestruction byheatthanare the tissues they grow in. 2. Heat acts synergistical ly with radiation in controlling the growth of many