The experimental analysis of the growth of cancer

Abstract

In the present paper we shall attempt to analyse the growth of cancer when propagated artificially in mice, mainly on the basis of 25,000 inoculations of Jensen’s tumour performed in conjunction with Dr. W. Cramer on behalf of the Imperial Cancer Research Fund; but also with reference to inoculations made with 32 other mouse tumours during the past three years. Ajthough the question of the continuous or interrupted nature of cancerous proliferation is of fundamental importance, both from the standpoint of the ultimate explanation of the nature of the disease, and from the standpoint of its treatment, such an analysis has never been attempted before. It has been assumed that the growth of cancer is vegetative, as inexplicable as an other form of growth, only to be partially understood by an elucidation of the processes by which normal tissues become cancerous. Artificial propagation processes by which normal tissues become cancerous. Artificial propagation enabled us to submit this assumption to the test of experiment, and imposed the necessity of determining by direct observation whether propagated cancer exhibited a mode of growth throwing light on the nature of the disease and the apparently continuous proliferation of sporadic tumours. While the experimental propagation of cancer may reveal new facts with a bearing on the nature of the disease it also affords opportunity for rational and empirical therapeutic experiments, and adequate opportunity for controlling the results. These two purposes have been constantly kept in view in our investigations. When a number of animals are inoculated with a transplantable mouse tumour, all do not develop tumours and the tumours which do develop are not all of the same size after the same interval. In order that propagated cancer might be available for the second of these purposes it was necessary to find out what influence the variable conditions of experiment exerted on the proliferation of the cells. In the course of these preliminary studies facts bearing on the nature of cancer have also been ascertained.