Popular Science Monthly/Volume 32/February 1888/Recent Views Respecting Cancer
|RECENT VIEWS RESPECTING CANCER.|
WHEN one of the gall-flies (cynips) stings the tender shoot of a rose-bush, the poison which is deposited along with her eggs excites at that portion of the twig an excessive degree of nutrition, and the resulting swelling becomes the home of the young of the fly.
The rose-bush gall is composed of nothing more than ordinary vegetable tissues; but they are abnormally developed, and there is an accompanying modification in the growth of normal structures. For instance, the vegetable hairs at that point may increase in size until they resemble large thorns, and an involved leaflet may lose its identity and become a part of the tumor. The color-grains (chlorophyll), which should give to the bark a green color, may show various shades of red instead. The rose-gall is not very different from the morbid growths of animal tissues which appear as tumors of various kinds; and we know that some, and presume that many, of the latter, are due to the disturbance caused by the presence of humble parasites belonging to the vegetable world. These parasites, or microbes, as they are called, are so small that it is impossible at present to study the life-histories of some of the species. No one has satisfactorily described any specific cancer-producing microbe, but it was only yesterday that we became acquainted with the cousins which cause the development of the tumors of glanders, of tuberculosis, of carbuncle, and of "big-head" (actinomycosis)—so that, reasoning by analogy, it seems more than probable that all malignant growths belong to the infectious microbic diseases, and that by to-morrow we shall have the tiny causators in a position in which they can be examined.
The malignant tumors of warm-blooded vertebrate animals are divided into two great classes—the sarcomas and the cancers. These growths are like the galls of various plants, in that they are composed not of new tissues, but of abnormally arranged tissues of ordinary character. Structures in their vicinity lose caste and become merged into tissue of some one type, just as the leaflet gives up its position as a lung for the rose and helps to build a house for the young gall-flies.
We have in cancer a sort of anarchy of cells, as it were, in which the leaders, whose work, for instance, consisted in the construction of muscle, are routed from their high positions and forced to become common members of a low organization.
Like many popular names the term cancer is indefinite, but it is principally used to distinguish three or four forms of malignant growth from the sarcomas and from benign tumors. The benign tumors grow within limiting capsules; pushing other tissues out of the way as they increase in size, and showing no tendency to affect the blood or to appear secondarily at different places in the body of the same patient. The malignant tumors, on the other hand, are those which are not limited by a capsule. They reach out and involve all kinds of tissue which happen to be near them; they infect the blood, and new colonies form at points situated at a distance from the parent growth. There is hardly a doubt but that malignant growths are quite local at the outset, but, like red ants, the microbes make more and more nests in the same field. As with red ants, too, we often fail to eradicate the colony, because many members may be away from home at the time when the nests are destroyed.
Malignant tumors have been produced in the dog by inoculation from an infected dog, in the horse by inoculation from the dog, and the horse has been inoculated from the horse. We are afraid that cancer is inoculable between animals and man, and between man and man, but on this point medical literature at present furnishes little reliable testimony.
Why it is that the cancer microbes which enter a cut on the surgeon's finger do not regularly produce cancer in the surgeon is a fact not easily explained. It is, however, a well-known fact, that certain other species of microbes are very particular about sites for their homes, and we may suppose that the cancer microbe finds a suitable field for growth in a relatively small number of persons.
When a malignant tumor is developing at any one point the lymphatic vessels in the vicinity are involved at an early date, and they eventually serve as channels for the passage of the disease into the blood.
If a far advanced primary growth of cancer could be stained in its entirety with a black dye, and if the patient were transparent, we should probably see that the tissues round about the growth were dusky, and that a thin, smoky coloring extended through the lymphatic vessels to the veins into which they empty. As a malignant tumor increases in size at its original situation the nerve filaments are pinched, and pain is caused as a rule; but sometimes the growth will progress with little or no accompanying pain.
When an operation by a competent surgeon is performed during the early stages of the disease, it may be eradicated completely; and even in cases in which considerable headway has been gained the surgeon is able to give long periods of immunity from the return of the growth. Patients, however, are unfortunately familiar with the traditions of old-time wound treatment, and the dread of an operation is so great that they seldom act in the matter until it is too late to hope for a cure.
The operation for the removal of a malignant growth causes no real suffering when it is done by the surgeons of to-day, who employ anesthetics for preventing pain during an operation and antiseptics for limiting inflammation afterward. The scientific antiseptic methods of wound treatment deal directly with species of microbes with which naturalists are familiar. According to present beliefs, suppuration and "blood-poisoning"—pyæmia, septicæmia, erysipelas, and lock-jaw—are due to the growth in the wound of microbes which are parasites there; and within the last few years we have learned how to stop the growth of these microbes, and to prevent inflammation after operations with mathematical accuracy. In the application of these methods to the work of removing malignant growths, operators fearlessly expose all infected tissues for great distances, and remove every vestige of the disease in cases in which a few years ago they would not have dared to operate thoroughly for fear of the resulting inflammation.
Treatment by medicines is of no avail in curing malignant growths. The reason why medicines are useless in such cases is evident if we look at the subject through the germ theory, for it can be readily understood that any drug which is powerful enough to destroy cancer microbes would also destroy the blood-corpuscles. It is safe to say, that we shall never have a drug which will cure cancer, in spite of the statements contained in the patent-medicine advertisements. Local applications of caustics for the purpose of curing cancer are seldom made by reputable surgeons to-day, because a glance at the anatomy of a malignant growth is sufficient to show the folly of attempting to reach the deeply-infected lymphatic vessels with anything except the fingers aided by sharp eyes. Very small malignant growths can be cured by means of the local application of caustics, and large growths can sometimes be removed temporarily; and as this is easily done, charlatans have found a large field for work by appealing to the patient's dread of the knife, and promising to cure by milder means. While the patient is trying other methods than the one which surgeons of responsibility employ, the disease is usually getting such a foothold that opportunities for help are lost.
Many lives would be saved daily if cancer patients could be so educated that the delusions which lead them to tamper with so-called blood-purifying medicines and with irregular methods of surgical treatment would give place to fairly good reason. There are no secret methods of cure, notwithstanding advertisements to the contrary; and there are no ways or means for the cure of cancer that are not known to the responsible surgeons of all civilized countries.
Probably little can be done, however, in the way of directing the majority of patients properly, because the emotions of a victim of the disease are apt to be exalted, and the intellectual faculties are in consequence deprived of the exercise which they would have in conducting the ordinary affairs of life.
Legislation which prohibits illicit medical practice and the sale of useless medicines is becoming more and more strict in the European countries and in the large American cities, and it is through proper legislation alone that we can expect to see any marked decrease in the number of deaths which yearly occur from cancer.