Preventable Diseases

by Woods Hutchinson

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.