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.

The nature of the process is a revolt of a group of cells. The cause of it is legion, for it embraces any influence which may detach the cell from its normal surroundings,—"isolate it," as one pathologist expresses it. The cure is early and complete amputation of not only the rebellious cells, but of the entire organ or region in which they occur.

A cancer is a biologic anomaly. Everywhere else in the cell-state we find each organ, each part, strictly subordinated, both in form and function, to the interests of the whole.

Here this relation is utterly disregarded. In the body-republic, where we have come to regard harmony and loyalty as the invariable rule, we find ourselves suddenly confronted by anarchy and revolt.

The process begins in one great class of cells, the epithelium of the secreting glands. This is a group of cell-citizens of the highest rank, descended originally from the great primitive skin-sheet, which have formed themselves into chemical laboratories, ferment-factories for the production of the various secretions required by the body, from the simplest watery mucus, as in the mouth, or the mere lubricant, as in the fat-glands of the hair-follicles, to the most complex gastric or pancreatic juice. They form one of the most active and important groups in the body, and their revolt is dangerous in proportion.

The movement of the process is usually somewhat upon this order: After forty, fifty, or even sixty years of loyal service, the cells lining one of the tubules of a gland—for instance, of the lip, or tongue, or stomach—begin to grow and increase in number. Soon they block up the gland-tube, then begin to push out in the form of finger-or root-like columns of cells into the surrounding tissues.

These columns appear to have the curious power of either turning their natural digestive ferments against the surrounding tissues, or secreting new ferments for the purpose, closely resembling pepsin, and thus literally eating their way into them. So rapidly do these cells continue to breed and grow and spread resistlessly in every direction, that soon the entire gland, and next the neighboring tissues, become packed and swollen, so that a hard lump is formed, the pressure upon the nerve-trunks gives rise to shooting pains, and the first act of the drama is complete.

But these new columns and masses, like most other results of such rapid cell-breeding in the body, are literally a mushroom growth. Scarcely are they formed before they begin to break down, with various results. If they lie near a surface, either external or internal, they crumble under the slightest pressure or irritation, and an ulcer is formed, which may either spread slowly over the surface, from the size of a shilling to that of a dinner-plate, or deepen so rapidly as to destroy the entire organ, or perforate a blood-vessel and cause death by hemorrhage. The cancer is breaking down in its centre, while it continues to grow and spread at its edge. Truly a "magnificent scheme of decay."

Then comes the last and strangest act of this weird tragedy. In the course of the resistless onward march of these rebel cell-columns some of their skirmishers push through the wall of a lymph-channel, or even, by some rare chance, a vein, and are swept away by the stream. Surely now the regular leucocyte cavalry have them at their mercy, and can cut them down at leisure. We little realize the fiendish resourcefulness of the cancer-cell. One such adrift in the body is like a ferret in a rabbit warren; no other cell can face it for an instant. It simply floats unmolested along the lymph-channels until its progress is arrested in some way, when it promptly settles down wherever it may happen to have landed, begins to multiply and push out columns in every direction, into and at the expense of the surrounding tissues, and behold, a new cancer, or "secondary nodule," is born (metastasis).

In fact, it is a genuine "animal spore," or seed-cell, capable of taking root and reproducing its kind in any favorable soil; and, unfortunately, almost every inch of a cancer patient's body seems to be such. It is merely a question of where the spore-cells happen to drift and lodge. The lymph-nodes or "settling basins" of the drainage area of the primary cancer are the first to become infected, probably in an attempt to check the invaders; but the spores soon force their way past them toward the central citadels of the body, and, one after another, the great, vital organs—the liver, the lungs, the spleen, the brain—are riddled by the deadly columns and choked by decaying masses of new cells, until the functions of one of them are so seriously interfered with that death results.

Obviously, this is a totally different process, not merely in degree, but in kind, from anything that takes place as a result of the invasion of the body by an infectious germ or parasite of any sort. There is a certain delusive similarity between the cancer process and an infection. But the more closely and carefully this similarity is examined the more superficial and unreal does it become. The invading germ may multiply chiefly at one point or focus, like cancer, and from this spread throughout the body and form new foci, and may even produce swarms of masses of cells resembling tumors, as, for instance, in tuberculosis and syphilis. But here the analogy ends.

The great fundamental difference between cancer and any infection lies in the fact that, in an infection, the inflammations and poisonings and local swellings are due solely and invariably to the presence and multiplication of the invading germs, which may be recovered in millions from every organ and region affected, while swellings or new masses produced are merely the outpouring of the body-cells in an attempt to attack and overwhelm these invaders. In cancer, on the contrary, the destroying organism is a group of perverted body-cells. The invasion of other parts of the body is carried out by transference of their bastard and abortive offspring. Most significant of all, the new growths and swellings that are formed in other parts of the body are composed, not of the outpourings of the local tissues, but of the descendants of these pirate cells. This is one of the most singular and incredible things about the cancer process: that a cancer starting, say, in the pancreas, and spreading to the brain, will there pile up a mass—not of brain-cells, or even of connective tissue-cells—but of gland-cells, resembling crudely the organ in which it was born. So far will this resemblance go that a secondary cancer of the pancreas found in the lung will yield on analysis large amounts of trypsin, the digestive ferment of the pancreas. Similarly a cancer of the rectum, invading the liver, will there pile up in the midst of the liver-tissue abortive attempts at building up glands of intestinal mucous membrane.

This fundamental and vital difference between the two processes is further illustrated by this fact: While an ordinary infection may be transferred from one individual to another, not merely of the same species, but of half a dozen different species, with perfect certainty, and for any number of successive generations, no case of cancer has ever yet been known to be transferred from one human being to another. In other words, the cancer-cell appears utterly unable to live in any other body except the one in which it originated.

So confident have surgeons and pathologists become of this that a score of instances are on record where physicians and pathologists, among them the famous surgeon-pathologist, Senn, of Chicago, only a few years ago, have voluntarily ingrafted portions of cancerous tissue from patients into their own arms, with absolutely no resulting growth. In fact, the cancer-cell behaves like every other cell of the normal body, in that, though portions of it can be grafted into appropriate places in the bodies of other human beings and live for a period of days, or even months, they ultimately are completely absorbed and disappear. The only apparent exception is the epithelium of the skin, which can be used in grafting or skinning over a wide raw surface in another individual. However, even here the probability appears to be that the taking root of the foreign cells is only temporary, and makes a preliminary covering or protection for the surface until the patient's own skin-cells can multiply fast and far enough to take its place.

A similarly reassuring result has been obtained in animals. Not a single authenticated case is on record of the transference of a human cancer to one of the lower animals; and of all the thousands and thousands of experiments that have been made in attempting to transfer cancers from one animal to another, only one variety of tumor with the microscopic appearance of cancer—the so-called Jensen's tumor of mice—has yet been found which can be transferred from one animal to another.

So we may absolutely disabuse our minds of the fear which some of our enthusiastic believers in the parasitic theory of cancer have done much to foster, that there is any danger of cancer "spreading," like an infectious disease. Disastrous and gruesome as are the conditions produced by this disease, they are absolutely free from danger to those living with or caring for the unfortunate victim. In the hundreds of thousands of cases of cancers which have been treated, in private practice, in general hospitals, and in hospitals devoted exclusively to their care, not a single case is on record of the transference of the disease to a husband, wife, or child, nurse or medical attendant. So that the cancer problem, like the Kingdom of Heaven, is within us.

This conclusion is further supported by the disappointing result of the magnificent crusade of research for the discovery of the cancer "parasite," whether vegetable or animal, which has been pursued with a splendid enthusiasm, industry, and ability by the best blood and brains of the pathological world for twenty years past. I say disappointing, because a positive result—the discovery and identification of a parasite which causes cancer—would be one of the greatest boons that could be granted to humanity; not so much on account of the actual loss of life produced by the disease as for the agonies of apprehension engendered by the fact of the absolute remorselessness and blindness with which it may strike, and our comparative powerlessness to cure. So far the results have been distressingly uniform and hopelessly negative.

Scores, yes, hundreds, of different organisms have been discovered in and about cancerous growths, and announced by the proud discoverer as the cause of cancer. Not one of these, however, has stood the test of being able to produce a similiar growth by inoculation into another body; and all which have been deemed worthy of a test-research by other investigators besides the paternal one have been found to be mere accidental contaminations, and present in a score of other diseases, or even in normal conditions. Many of them have been shown to be abnormal products of the cells of the body in the course of the cancer process, and some even such ludicrous misfits as impurities in the chemical reagents used, scrapings from the corks of bottles, dust from the air, or even air-bubbles. These "discoveries" have ranged the whole realm of unicellular life,—bacilli, bacteria, spirilla, yeasts, moulds, protozoa,—yet the overwhelming judgment of broad-minded and reputable experts the world over is the Scotch verdict of "not proven"; and we are more and more coming to turn our attention to the other aspect of the problem, the factors which cause or condition this isolation and assumption of autonomy on the part of the cells.

This is not by any means to say that there is no causative organism, and that this will not some day be discovered. Human knowledge is a blind and short-sighted thing at best, and it may be that some invading cell, which, from its very similarity to the body-cells, has escaped our search, will one day be discovered. Nor will the investigators diminish one whit of their vigor and enthusiasm on account of their failure thus far.

The most strikingly suggestive proof of the native-born character of cancer comes from two of its biologic characters. The first is that its habit of beginning with a mass formation, rapidly deploying into columns and driving its way into the tissues in a ghastly flying wedge, is simply a perfect imitation and repetition of the method by which glands are formed during the development of the body. The flat, or epithelial, cells of the lining of the stomach, for instance, begin to pile up in a little swarm, or mass, elongate into a column, push their way down into the deeper tissue, and then hollow out in their interior to form a tubular gland. The only thing that cancer lacks is the last step of forming a tube, and thereby becoming a servant of the body instead of a parasite upon it.

Nor is this process confined to our embryonic or prenatal existence. Take any gland which has cause to increase in size during adult life, as, for instance, the mammary gland, in preparation for lactation, and you will find massing columns and nests of cells pushing out into the surrounding tissue in all directions, in a way that is absolutely undistinguishable in its earlier stages from the formation of cancer. It is a fact of gruesome significance that the two organs—the mammary gland and the uterus—in which this process habitually takes place in adult life are the two most fatally liable to the attack of cancer.

Another biologic character is even more striking and significant. A couple of years ago it was discovered by Murray and Bashford, of the English Imperial Cancer Research Commission, that the cells of cancer, in their swift and irregular reproduction, showed an unexpected peculiarity. In the simplest form of reproduction, one cell cutting itself in two to make two new ones, known as mitosis, the change begins in the nucleus, or kernel. This kernel splits itself up into a series of threads or loops, known as the chromosomes, half of which go into each of the daughter cells. When, however, sex is born and a male germ-cell unites with a female germ-cell to form a new organism, each cell proceeds, as the first step in the process, to get rid of half of these chromosomes, so that the new organism has precisely the normal number of chromosomes, half of which are derived from the father and the other half from the mother germ-cell. This, by the way, is the mechanical basis of heredity.

It has been long known that the mitotic processes of cancer and the forming and dividing of the chromosomes were riotous and irregular, like the rest of its growth. But it was reserved for these investigators to discover the extraordinary fact that the majority of dividing and multiplying cancer-cells had, instead of the normal number of chromosomes, exactly half the quota. In other words, they had resumed the powers of the germ, or sexual, cells from which the entire body was originally built up, and were, like them, capable of an indefinite amount of multiplication and reproduction. How extraordinary and limitless this power is may be seen from the fact that a little group of cancer-cells grafted into a mouse to produce a Jensen tumor, from which a graft is again taken and transplanted into another mouse, and so on, is capable, in a comparatively few generations, of producing cancerous masses a thousand times the weight of the original mouse in which the tumor started!

In short, cancer-cells are obviously a small, isolated group of the body-cells, which in a ghastly fashion have found the fountain of perpetual youth, and can ride through and over the law-abiding citizens of the body-state with the primitive vigor of the dawn of life.

This brings us to the most practical and important questions of the problem: What are the influences which condition this isolation and outlawry of the cells? What can we do to prevent or suppress the rebellion? To the first of these science can only return a tentative and approximate answer. The subject is beset with difficulties, chief among which is the fact that we are unable to produce the disease with certainty in animals, with the single exception of the Jensen's tumors in mice referred to, nor is it transferred from one human being to another, so that we can make even an approximate guess at the precise time at, or conditions under, which the process began.

Many theories have been advanced, but most investigators who have studied the problem in a broad-minded spirit are coming gradually to agree to this extent:—

First of all, that one of the most powerful influences conditioning this isolation and revolt of the cells is age, both of the individual and of the organ concerned. Not only does far the heaviest cancer mortality fall between the ages of forty-five and sixty, but the organs most frequently and severely attacked are those which between these years are beginning to lose their function and waste away. First and most striking, the mammary gland and the uterus in women, and the shriveling lips and tongue of elderly men. To put it metaphorically, the mammary gland and the uterus, after the change of life, the lip, after the decay of the teeth, have done their work, outlived their usefulness, and are being placed upon a starvation pension by a grateful country. Nineteen out of twenty accept the situation without protest and sink slowly to a mere vegetative state of existence, but, in the twentieth, some little knot of cells rebel, revert to an ancestral power of breeding rapidly to escape extinction, begin to make ravages, and cancer is born.

The age-preferences are well marked. Cancer is emphatically a disease of senility, of age; but, as Roger Williams has pointed out in his admirable monograph, not of "completed" senility.

To express it in percentages, barely twenty per cent of the cases occur before forty years of age, sixty per cent between forty and sixty, and twenty per cent between sixty and eighty. Thus the early period of decline, the transition stage between full functional vigor and declared atrophy (wasting) of the glands, is clearly the period of greatest danger; precisely the period in which the gland-cells, though losing their function,—and income,—have still the strength to inaugurate a rebellion, and a sufficient supply of the sinews of war, either in their own possession or within easy striking distance in the tissues about them, to make it successful. Not less than sixty-five to seventy-five per cent of all cancers in women occur in atrophying organs, the uterus and mammary glands.

A rather alluring suggestion was made by Cohnheim, years ago, that cancers might be due to the sudden resumption of growth on the part of islands or rests of embryonic tissue, left scattered about in various parts of the body. But these are now believed to play but a small part, if indeed any, in the production of true cancer.

Finally, what can be done to prevent or cure this grotesque yet deadly process? So far as it is conditioned by age, it is, of course, obvious that little can be done, for not even the most radical vivisector would propose preventing in any way as large a proportion as possible of the human race from reaching fifty or sixty, or even seventy years, to avoid the barely six per cent liability to cancer after forty-five.

As regards the influence of chronic inflammations and irritation, much can be done, and here is our most hopeful field for prevention. Warts and birthmarks that are in any way subject to pressure or friction from clothing or movements should be promptly removed, as both show a distinctly greater tendency than normal tissue to develop into cancer. Cracks, fissures, chafes, and ulcers of all sorts, especially about the lips, tongue, mammary gland, uterus, and rectum, should be early and aseptically dealt with. Jagged remnants of teeth should be removed, all suppurative processes of the gums antiseptically treated, and the whole mouth-parts kept in a thoroughly aseptic condition.

Thorough and conscientious attention to this sort of surgical toilet work is valuable, not only for its preventive effect,—which is considerable,—but also because it will insure the bringing under competent observation at the earliest possible moment the beginnings of true cancer.

For the disease itself, after it has once started, there is, like treason in the body-politic, but one remedy—capital punishment. Parleying with the rebels is worse than useless. Pastes, caustics, X-rays, trypsin, radium,—all are fatally defective, because they suppress a symptom only and leave the cause untouched. Only in one form of surface-cancer, the so-called flat-celled or rodent ulcer, which has little or no tendency to form spore-cells and attack the deeper organs, are they effective.

Nothing is easier and nothing more idle than to destroy and break down cells which have actually become cancerous; but so long as there remains in the body a single nest, or even cell, of the organ in which the revolt started, so long the life of the patient is in danger.

Absolutely the only remedy which is of the slightest value is complete removal with the knife. The one superiority of the knife, shudder as we may at the name of it, over every other means of removal lies solely in this fact, that with it can be removed not merely the actual cancer, but the entire gland or group of surrounding cells in which this malignant, parricidal change has begun to occur.

The modern radical operations for cancer take not merely the tumor, but the entire diseased breast, for instance, and all the lymph-glands into which it drains, clear up into the armpit, with the muscles beneath it down to the ribs. Where this is done early enough, the disease does not recur. Such radical and complete amputation of an organ or region as this is possible in from two-thirds to three-fourths of all cases if seen reasonably early.

With watchfulness and courage, our attitude toward the cancer problem is one of hopeful confidence.