CANCER'S PLACE IN GENERAL BIOLOGY 



W. C. MacCARTY, m.d. 

 Mayo Clinic, Rochester, Minx. 



The condition which has been called cancer by the laity 

 and the medical profession has been studied by the latter 

 largely from the standpoint of disease. Investigators 

 have considered its great destructive action, cause, pre- 

 vention and treatment, all of which study has been stimu- 

 lated by the urgent necessity of its eradication from the 

 ills of man, and not in its relation to the known biologic 

 facts concerning the universal conflict between living 

 normal cells and their natural enemies. In order to ap- 

 proach correctly this biologic phase of the condition it 

 will be necessary to answer the question : What is cancer ? 



To the pathologist, cancer is a cellular overgrowth 

 which occurs in some multicellular organism, especially 

 in man, and which is characterized by its apparently un- 

 limited proliferation, during which it destroys tissues, 

 and is fatal eventually to the whole organism. This, in 

 general, is the conception held by the members of the 

 medical profession, but to the scientific mind which is 

 interested in and trained in the fundamental or more 

 specific factors operating in living nature, it is neither 

 satisfactory nor sufficient. 



An analysis of the condition from such a biologic point 

 of view necessitates also for its elucidation a study of the 

 facts relative to the evolution of multicellular organisms 

 from single cells as units of life. Biologists agree that 

 the cell is the visible unit of life, and that all cells have 

 certain fundamental structural and functional character- 

 istics which are common to all. They further agree that 

 all multicellular beings evolve by a process of division 

 or segmentation of a single cell which has been stimu- 

 lated automatically, or by the process of extrinsic fertili- 

 zation to such activity. 



During the process of segmentation certain dominant 

 facts present themselves. A fertilized ovum, for exam- 

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