414 Tumors. 



general emaciation, anaemia and bodily weakness, known as can- 

 cerous cachexia, due at least in part to the reaction upon the 

 system by toxic products formed in the cancerous tissue. 



[The cachexia of cancer is of course induced the more early and 

 markedly in case the cancer involve some of the organs of nutri- 

 tional importance to the- animal, as the alimentary tube or pancreas; 

 the faults of nutrition being important contributors to the produc- 

 tion of oligaemia and loss of flesh and strength. The idea of toxic 

 factors, although usually not urged by writers because of our ig- 

 norance, is, however, probably an important one, these toxines aris- 

 ing from the secretory activity of the tumor tissue or as products 

 of tissue metabolism or destruction. The metastatic tendency, in- 

 volving the progressive affection of more and more of the body by 

 cancerous foci, must of course be an important factor of malig- 

 nance. The occurrence of metastases varies greatly with the type 

 of the tumor and with the definite resistive power which the body 

 exerts against these practically parasitic cells, this resistance being 

 apparently not at all uniformly possessed by the various organic 

 systems or by different individuals. In a general way it may be 

 said that the squamous epitheliomata are likely to disseminate more 

 slowly than the other varieties, progressing more regularly by a con- 

 tinuous invasion of the lymph spaces and channels, and therefore 

 showing a greater tendency to local and neighboring infiltration and 

 node production. Distant metastases are to be met with but are not 

 as frequent as in the cylindrical cell and glandular cell cancers. Of 

 the latter groups in a rough way, to which exceptions are common, 

 it may be said that those that manifest in their structure the great- 

 est departure from the tubular and acinous types (carcinoma sim- 

 plex) are those showing the more rapid and extensive metastatic 

 tendency ; the adenocarcinomatous forms the less. Both are, how- 

 ever, more apt to give distant metastasis than the squamous cell 

 form. The condition of the stroma makes a difference as well, the 

 soft medullary types with a small amount of stroma being more 

 metastatic and the hard scirrhous varieties tending to remain local 

 for a longer period. It is said that cancers as a group are char- 

 acteristically generalized by way of the lymphatic system, in contrast 

 to sarcomata which are more frequently conveyed by the blood cur- 

 rent. This is, in the main, true, and the usual rule is to find the 

 lymph glands into which the lymph drainage of the cancerous part 

 passes the seat of secondary cancers. Yet it is by no mean? neces- 

 sarv. The route of metastasis and in a great measure the tendency 



