Cancer as a Special Case of a General Degenerative Process 



349 



and older (Fig. 2). This merging of the three plots at the age of forty and older 

 demonstrates a well-known fact, that chronic degenerative diseases become 

 most important as cause of death at the older ages; the values show essentially 

 no change over the period from 1900-1951. On the other hand, at the earlier 

 ages, the acute causes constitute almost 100 per cent of the total death rate, 

 and chronic degenerative diseases represent only a minor fraction. Even though 



20 



40 60 80 100 



AGE 



Fig. 2. Log-log plot of 1000^^ against age for United States white males for 

 1900-1902, 1929-1931, and 1949-1951. Lines are omitted in order to show more 

 clearly the good fit of the three sets of points on the straight portion of the 



curve. 



it is apparent that acute causes have been decreasing steadily over the fifty-year 

 period from 1900-1951, their presence is evident as departures from the straight 

 line in the plots, with highest values at 1900-1902 and lowest at 1949-1951. 

 The equation of the straight line for the forty years and older group was 

 calculated on the assumption that the 1949-1951 values represented the least 

 effect of acute causes of death on the over-all figures. This was regarded as 

 giving q^ values for the degenerative causes of death which were then subtracted 

 from the total q^ values for other countries. The resulting numbers were assumed 

 to represent death rate attributable to acute causes of death. 



The ^a,'s associated with these acute causes of death were found to plot 

 as a simple exponential increase with age. The slopes were equal for the 

 countries tested, but the intercepts were different and correlated in a general 

 way with the levels of public health and medical care in the country concerned. 

 Plots for four of the countries are shown in Fig. 3a. When the sum of the five 

 major groups of degenerative diseases was similarly subtracted from the total 

 causes of death in United States white males 1949-1951, leaving a residue 



