The Nature of the Disease

Abstract

Cellular division is normal (mitosis); from the moment of conception onwards multiplication and replacement is an ordered process. The trophoblasts of the placenta invade the uterus but stop in response to some as yet unknown control. When I saw the dissection of a three-month embryo I realised with wonder that the foetus, though miniature, was complete and that from now on only growth, repair, and replacement would take place in an orderly sequence. Rapid replacement of tissues suffering wear and tear means cells are in a constant state of mitosis, skin layers are continually worn and replaced, red cells have a limited life and the population must be maintained, and epithelial cells of the gut are constantly shed and renewed. The hallmark of all this cellular activity is order and control maintaining a constant balance. The factors which initiate and terminate the whole process are as yet undiscovered. It is when one or more cells escape from this control that the process of malignancy starts. Growth becomes uncontrolled, disorderly, and invasive, and the normal equilibrium is disturbed.