It seems reasonably clear that the eventual solution of the cancer problem will come only with a better understanding of fundamental biological principles. Cancer is unquestionably closely related to the phenomenon of growth. It differs from normal growth in that it is unrestricted overgrowth atypical in organization. It follows, therefore, that to understand the natural history of neoplasms, knowledge of growth and organization must be widened and deepened. While much is known about growth because of the marked increase of studies of this phenomenon in recent years, the more fundamental problem of biological organization still lacks any definite answer.
As a first approximation to the solution of this age-old problem Burr, in 1932, formulated an electrodynamic theory of organization and, in 1935, Burr and Northrop further developed and elaborated the idea. As formulated, this theory held that all living organisms possess a relatively steady state electro-dynamic field, generated as a part of the fundamental attributes of protoplasm, and organized to form an electrical field which imposes a characteristic pattern on the development of the living organism. Should this theory eventually prove to be sound—and numerous studies suggest that it is—the presence of cancer should show signs of a determinable deviation in the electrical pattern of the normal organism.
The development of an adequate technique by Burr, Lane and Nims (1936) made it possible to initiate a series of studies designed to investigate the bio-electric properties of an organism before, during, and after the onset of cancer. The animals chosen for this study were from the mouse colonies of Dr. Leonell C. Strong (1936). Each strain has been inbred for many generations so that the genetic constitution of each animal is as nearly like that of others of the same strain as is possible. One strain, the CBA, was bred for relative immunity to adenocarcinoma of the mammary gland. The second strain, A, has been inbred so that approximately 90 per cent of the population of breeding females acquire mammary cancer during their normal lives. The electrical measurements were begun as early as practicable in the life history of the animals, about the 150th day. These measurements were carried on until the individual died or was killed.