The imagination of the race has ever endowed Cancer with a peculiar individuality of its own. Although it has vaguely personified in darkest ages other diseases, like the Plague, the Pestilence, and Maya (the Smallpox), these have rapidly faded away in even the earliest light of civilization, and have never approached in concreteness and definiteness the malevolent personality of Cancer. Its sudden appearance, the utter absence of any discoverable cause, the twinges of agonizing pain that shoot out from it in all directions, its stone-like hardness in the soft, elastic flesh of the body, the ruthless way in which it eats into and destroys every organ and tissue that come in its way, make this impression, not merely of personality, but of positive malevolence, almost unescapable.
Its very name is instinct and bristling with this idea: Krebs, in German, Cancer, in Latin, French, and English, Carcinoma, in Greek, all alike mean "Crab," a ghastly, flesh-eating parasite, gnawing its way into the body. The simile is sufficiently obvious. The hard mass is the body of the beast; the pain of the growth is due to his bite; the hard ridges of scar tissue which radiate in all directions into the surrounding skin are his claws.
The singular thing is that, while brushing aside, of course, all these grotesque similes, the most advanced researches of science are developing more and more clearly the conception of the independent individuality—as they term it, the autonomy—of cancer.
More and more decidedly are they drifting toward the unwelcome conclusion that in cancer we have to deal with a process of revolt of a part of the body against the remainder, "a rebellion of the cells," as an eminent surgeon-philosopher terms it. Unwelcome, because a man's worst foes are "they of his own household." Successful and even invigorating warfare can be waged against enemies without, but a contest with traitors within dulls the spear and paralyzes the arm. Against the frankly foreign epidemic enemies of the race a sturdy and, of late years, a highly successful battle has been fought. We have banished the plague, drawn the teeth of smallpox, riddled the armor of diphtheria, and robbed consumption of half its terrors. In spite of the ravings and gallery-play of the Lombroso school anent "degeneracy," our bills of mortality show a marked diminution in the fatality of almost every important disease of external origin which afflicts humanity.
The world-riddle of pathology the past twenty years has been: Is cancer due to the invasion of a parasite, a veritable microscopic crab, or is it due to alterations in the communal relations, or, to speak metaphorically, the allegiance of the cells? Disappointing as it may be, the balance of proof and the opinion of the ablest and broadest-minded experts are against the parasitic theory, so far, and becoming more decidedly so. In other words, cancer appears to be an evil which the body breeds within itself.
There is absolutely no adequate ground for the tone of lamentation and the Cassandra-like prophecy which pervade all popular, and a considerable part of medical, discussion of the race aspects of the cancer problem. The reasoning of most of these Jeremiahs is something on this wise: That, inasmuch as the deaths from cancer have apparently nearly trebled in proportion to the population within the last thirty years, it only needs a piece of paper and a pencil to be able to figure out with absolute certainty that in a certain number of decades, at this geometric ratio, there will be more deaths from cancer than there are human beings living.
There could be no more striking illustration, both of the dangerousness of "a little knowledge" and of the absurdity of applying rigid logic to premises which contain a large percentage of error. Too blind a confidence in the inerrancy of logic is almost as dangerous as superstition. Space will not permit us to enter into details, but suffice it to say:—
First, that expert statisticians are in grave doubt whether this increase is real or only apparent, due to more accurate diagnosis and more complete recording of all cases occurring. Certainly a large proportion of it is due to the gross imperfection of our records thirty years ago.
Second, that the apparent increase is little greater than that of deaths due to other diseases of later life, such as nervous, kidney, and heart diseases. Our heaviest saving of life so far is in the first five-year period, and more children are surviving to reach the cancer and Bright's disease age.
Third, that a disease, eighty per cent of whose death-rate occurs after forty-five years of age, is scarcely likely to threaten the continued existence of the race.