328 On the Origin of Cancer Cells 



Recently we have confirmed this result by direct experiments in which we placed 

 varying amounts of energy at the disposal of the ascites outside the body, in vitro, 

 and then transplanted it. This investigation showed that all Cancer cells were killed 

 when no energy at all was supplied for 24 hours at 38° C but that one-fifth of the 

 growth energy was sufficient to preserve the transplantability of the ascites. This 

 result can also be expressed by saying that Cancer cells require much less energy 

 to keep them alive than they do for growth. In this they resemble other lower cells, 

 such as yeast cells, which remain alive for a long time in densely packed packets — 

 almost without respiration and fermentation. 



In any case, the ability of Cancer cells to survive with little energy, if they are not 

 growing, will be of great importance for the behavior of the Cancer cells in the body. 



Sleeping Cancer Cells 



Since the increase in fermentation in the development of Cancer cells takes place 

 gradually, there must be a transitional phase between normal body cells and fully 

 formed Cancer cells. Thus, for example, when fermentation has become so great 

 that dedifferentiation has commenced, but not so great that the respiratory defect 

 has been fully compensated for energetically by fermentation, we may have cells 

 which indeed look like Cancer cells but are still energetically insufficient. Such cells, 

 which are clinically not Cancer cells, have lately been found, not only in the pro- 

 state, but also in the lungs, kidney, and stomach of elderly persons. Such cells 

 have been referred to as "sleeping Cancer cells" 11 ' 12 . 



The sleeping Cancer cells will possibly play a role in chemotherapy. From energy 

 considerations, I could think that sleeping Cancer cells could be killed more 

 readily than growing Cancer cells in the body and that the most suitable test objects 

 for finding effective killing agents would be the sleeping Cancer cells of skin — that 

 is, precancerous skin. 



Summary 



Cancer cells originate from normal body cells in two phases. The first phase 

 is the irreversible injuring of respiration. Just as there are many remote causes of 

 plague — heat, insects, rats — but only one common cause, the plague bacillus, 

 there are a great many remote causes of Cancer — tar, rays, arsenic, pressure, ure- 

 thane — but there is only one common cause into which all other causes of Cancer 

 merge, the irreversible injuring of respiration. 



The irreversible injuring of respiration is followed, as the second phase of Cancer 

 formation, by a long struggle for existence by the injured cells to maintain their 

 structure, in which a part of the cells perish from lack of energy, while another 

 part succeed in replacing the irretrievable lost respiration energy by fermentation 

 energy. Because of the morphological inferiority of fermentation energy, the highly 

 differentiated body cells are converted by this into undifferentiated cells that grow 

 wildly — the Cancer cells. 



To the thousands of quantitative experiments on which these results are based, 

 I should like to add, as a further argument, the fact that there is no alternative 



