SYMPOSIUM ON PUBLIC HEALTH PROBLEMS 97 
CANCER AS A PUBLIC HEALTH PROBLEM 
Dr. J. F. Percy, GALESBURG 
Of all the public health problems that confront the so-called 
civilized portion of mankind, cancer is admittedly one of the 
most important. 
Up to the time of the present war, it was estimated that at 
least 30,000 scientific men and women were devoting their time 
to unraveling the mystery of its causation. As to what this is, 
there is absolutely nothing known at the present time. One 
thing seems to be positively known about cancer, viz: that in 
its beginnings, it is a local disease. Whether this local condi- 
tion is caused by a germ or a cell is, however, not known. The 
theory on which the advocates of either the germ or the cell 
idea of its causation is based is most convincing until one reads 
the views and arguments on the other side of the question. 
There is a popular notion that a tumor and cancer are two 
different conditions. This is not true. Tumor means any 
growth. Every cancer is a tumor but every tumor is not a 
cancer. For the purpose of this paper I am going to assume 
that cancer is due to the misplaced activity of the body cells 
at the point of origin of the disease. 
As you will readily recall, the tissues of the body are made up 
of many cells. They have been likened to the bricks in a house, 
one upon the other in a marvelously orderly arrangement. 
But they differ from the bricks in the wall of the house in that 
they are never still. They divide and subdivide indefinitely. 
As soon as the mother cells are worn out, daughter cells take 
their place. One beautiful characteristic of these developing 
cells is that they always respect their neighbor cells and never 
invade foreign territory. Each kind of tissue in the body, 
whether it is bone or muscle, nerve structure or skin, has its 
own peculiar cells. Each of these groups of cells does its own 
work and follows its own cycle of life. When a tumor that is 
not cancer, develops in any one of these four groups of cells, 
it is always made up of the cells characteristic of that tissue. But 
when a tumor develops that the expert pathologist, aided by the 
eye of the microscope, pronounces cancer, the whole orderly 
arrangement of the cells in any of these tissues is wholly 
changed. 
