201 



The Manifestation of Active Resistance to the Growth of Implanted 

 Cancer. 

 By B. B. G. Bussell, M.D. 



(Communicated by Sir John Bose Bradford, Sec. B.S. Beceived March 15, — • 

 Bead May 2, 1912.) 



(From the Laboratory of the Imperial Cancer Research Fund.) 



The current classification of neoplasms has been almost entirely founded 

 upon their structural characters, qualified wherever possible by the knowledge 

 available upon their histogenesis. The researches which have been made, 

 more especially with transplanted tumours of the rodents, have superadded 

 to the recognised morphological differences and resemblances which tumours 

 exhibit, much information upon the more physiological side of their activities, 

 and have shown how variable tumour strains may be in their manner of 

 growth. In the present communication, the individuality of various trans- 

 plantable tumour strains will be brought out by subjecting them to ant 

 analysis with a new factor. This factor will be the quality of the reaction 

 which a strain induces when implanted into a fresh series of animals, and 

 this reaction will be tested by showing how the animals behave to subsequent- 

 inoculation of a transplantable tumour. In essence, therefore, the test 

 applied is one for the presence or absence of a soil suitable for the sowing 

 of tumour cells. The completion of this analysis will be followed by the 

 exposition of a series of experiments bearing more especially upon the 

 range of action of the unsuitability of the soil which can be artificially 

 induced. 



The propagation during an extended period of over 80 different tumour 

 strains in the laboratories of the Imperial Cancer Besearch Bund* has 

 provided an extensive material, presenting very different types of growth, 

 and suitable for a comparative analysis. Exactly what is conveyed by the 

 term, type of growth, will be apparent from the two accompanying figures 

 of tumour strains T and 206. Strain T, shown in fig. 1, has given rise to a. 

 slowly but progressively growing tumour in 20 out of 21 mice, whereas with 

 strain 206 (fig. 2) all tumours have finally disappeared spontaneously. These 

 two carcinomatous strains exemplify the possible extremes of type of growth, 

 and the intermediate gradations between them have been actually filled up 



* Bashford, E. F., "The Behaviour of Tumour-cells during Propagation," 'Fourth 

 Scientific Eeport of the Imperial Cancer Research Fund,' 1911, p. 131. 



VOL. LXXXV. — B. P 



