DISTRIBUTION OF B VITAMINS 27 



tumors of various types almost without exception the same order of 

 occurrence was observed as in other studies, with inositol the most abun- 

 dant and biotin the least abundant of the six. Some of the specimens 

 assayed were estimated to be 70-80 per cent cancer tissue, while a few 

 contained as little as 20 per cent. 16 - co - 61 - 62 > 63 



For comparing a group of tissues with each other, on the basis of their 

 content of B vitamins, a simple mathematical scheme was used by which 

 to calculate from the assay values the coefficient of uniformity (100 per 

 cent minus the coefficient of variation) of the group of tissues compared. 

 On this basis eight diverse normal human tissues showed a uniformity of 

 only 27 per cent, whereas eight diverse cancers showed a much higher 

 uniformity, namely, 66 per cent. Three normal human tissues (kidney, 

 ovary and mammary gland) showed a uniformity of only 11 per cent, 

 whereas three cancers derived from these same three tissues showed a 60 

 per cent uniformity. These observations led to the idea that cancer tissue, 

 regardless of its origin, may represent, from the standpoint of its inherent 

 metabolic machinery, a specific tissue type. 



Further evidence supporting this idea was obtained by comparing vari- 

 ous groups of tissues as indicated in Table 3. 



Table 3. "Vitamin Uniformity" in Human, Rat, and Mouse Normal and 

 Cancer Tissues. 



Coefficient of Uniformity 



8 diverse normal rat tissues 29.7 

 5 rat cancers of diverse origin 62.8 



9 heart tissues from mice 76.0 

 12 diverse mouse cancers 58.0 



9 heart tissues, 3 each from human, rat and mouse 61.2 



22 cancers (8 human, 5 rat, 9 mouse) 53.3 



In all cases when groups of cancers were compared, regardless of whether 

 they originated in humans, in rats or mice, or in what type of tissue they 

 originated or whether they were induced or spontaneous, the coefficient 

 of uniformity was above 50 per cent; however, when diverse tissues, for 

 example, those in which the cancers originated, were compared, the uni- 

 formity was far lower than this. 



The conclusion derived from these findings is important because it has 

 been corroborated, largely on the basis of enzyme studies. In this connec- 

 tion, Greenstein says, "It is possible to speak of cancer tissue in much 

 the same way as one speaks of hepatic tissue or renal tissue, namely as 

 a tissue with limited and ascertainable properties." 64 



In general, cancer tissue (on a moist basis) tends to have a relatively 

 low content of B vitamins, perhaps 50 per cent as much as an average of 

 other mammalian tissues. Part of this difference is due to the relatively 

 high water content of cancer tissue. However, some of the B vitamins, 



