CHAPTER X 



DEFINITION OF THE TERM ' CANCER,' ETC. 



THE term ' cancer ' in this book refers to the common forms of 

 malignant disease, whether of the epithelial type (carcinoma proper) 

 or of the connective-tissue type i.e., sarcoma. These are the 

 instances of disease which have given the word ' cancer ' its meaning 

 among the civilized races of mankind. In the present state of 

 knowledge, under the heads of cancer and sarcoma diseases of 

 varied origin and causation are possibly included, and when their 

 causation is more definitely established various distinct groups may 

 require to be made where only one now exists. It is important to 

 examine most closely in every way, clinically, microscopically, and 

 experimentally, the commonest and most typical of the instances of 

 cancer. If it is found that these commoner forms can be grouped 

 together on the ground of their having a similar causation, then it is 

 to this group that the name ' cancer ' must be given, and for other 

 rarer forms other names must be sought. Such common examples 

 are the epithelial cancers of the skin, the mouth, the gullet ; of the 

 stomach, intestine, and gall-bladder; of the kidney, bladder, and 

 prostate ; of the breast and uterus ; of the ovary or testis, etc. ; and 

 connective-tissue cancers of the fibrous tissue, of various parts of 

 the body, of lymphatic glands, bone, etc. 



The first rational step in relation to the investigation of a disease 

 which involves change in the structure of the tissues is to consider 

 the cellular constitution of all living things as established by 

 Schleiden and Schwann about 1838, and to remember that every 

 disease involves a disturbance of the arrangement or condition of 



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