CHEMOTHERAPY IN MALIGNANT DISEASE 279 



the body, of whatever kind, will invariably lead to a response on 

 the part of the macroorganism which is in the end of a protective 

 character. It may accordingly not be out of place in a book of this 

 character to briefly review some of the more promising lines of inves- 

 tigation in the domain of chemotherapy which are at the present 

 time occupying the attention of students of the cancer problem. 

 That the problem should be intrinsically more difficult in malignant 

 disease goes of course without saying, for it is here not only a question 

 of finding a substance which would have a low grade of affinity 

 for the body cells coupled with a high grade of affinity for a cell 

 which is a perfect stranger to the macroorganism, but we must 

 actually find a product which shall have a high affinity for a type 

 of cell which after all is a product of the same organism against 

 whose normal cells, so to speak, its affinity must be low. The pos- 

 sibility of actually finding a substance of this character will naturally 

 depend upon the question whether the proliferating cell, which for 

 want of a better term we may speak of as the cancer cell, is struc- 

 turally and functionally identical with the normal cell from which 

 it has originated, or whether any points of difference exist between 

 the two types. While this question still awaits its final answer, 

 we may say that there is some evidence to show that points of differ- 

 ence do exist between the normal and the abnormal cell, and that 

 the problem is hence a priori not a hopeless one. 



The most interesting studies which have a bearing upon the 

 possibility of effecting a cure of cancer along the lines of modern 

 chemotherapy have been published by A. v. Wassermann and his 

 collaborators. 



The investigations of these observers were based upon the dis- 

 covery by Gosio that sodium selenate and sodium tellurate are more 

 rapidly reduced by cancer cells than by normal cells, and that this 

 reduction takes place within the bodies of the cells. Experiments on 

 tumor mice then showed that the injection of these substances into 

 the growths may actually lead to their complete destruction. The 

 problem now was to devise some method by which the selenium or 

 the tellurium could be carried to the tumor through the circulation 

 in order to prove that the substance in question actually possesses 

 a selective affinity for the tumor cell, and remembering also that 

 the complete eradication of the malignant growth, excepting in the 

 very earliest stage of the disease, can scarcely be expected by means 



