The conquest of cancer

by H. W. S. Wright

The commonest sites for cancer are the womb, the breast, and the stomach. These together account for more than sixty per cent. of all cancers, and far below them in frequency we find the tongue, the lip, and the bowel, and the various glands.

Cancer of the womb is constantly preceded for many years by disease, palpable and curable, often the result of childbearing, and the part where it occurs is one bathed in an acid medium.

Cancer of the breast also is constantly associated with preceding chronic inflammation, this condition itself producing, as one of its by-products, a highly acid substance, further to irritate the delicate cells already near the end of their tether. Mechanical irritation, beyond a doubt, is an important factor. Although in civilised countries the disease is distressingly common, in those countries where the breasts are habitually uncovered, cancer of this organ is extremely rare. The habitual friction of modern clothes predisposes cell-growth, infection from no matter what source is given a foothold, and after years of abuse, the cells lose the impulse to normal reaction and at last turn and slay their victim.

There is evidence that about two-thirds of all the cases of cancer of the stomach originate in an old gastric ulcer, and the constant eating of hot food is perhaps enough to account for the remaining third. The delicate gastric cells, more abused than any other cells in the body, are bathed in a highly acid medium. It is no wonder that departure from their appointed path accounts for thirty per cent. of all cancers in men, and in women as well, if we except the two conditions just mentioned.

In cancer of the kidney, the bladder, and the gall bladder, stones are nearly always present to initiate the irritation.

In cancer of the tongue, syphilitic or other preceding conditions are nearly always there, whether it be the irritation from raw alcohol, hot tobacco smoke, or a broken tooth. It is interesting to note that, until syphilis appeared in Europe, cancer of the tongue was practically unrecorded in the existing literature. We have no need to go any further for examples of these precancerous irritative conditions. They are all curable or removable, but, as they do not as a rule give rise to acute painful symptoms, severely inconveniencing the patient, they are difficult to treat, and the unfortunate patient is told to wait and see, and is given medicine which may for a while relieve, but which—alas!—seldom has a chance to cure, or to prevent the fate which is slowly overtaking him.

So far the evidence which has been brought before you, that chronic irritation has a causal connection with cancer, has been of a circumstantial nature: it has often enough been found in what we may call suspicious circumstances, but that does not prove that by itself it can directly cause the disease. If a man is seen hanging about the place where a burglary has been committed, it does not prove that he participated in it. He may be a burglar, or he may be what lawyers call an accessory before the fact, and before we can feel reasonably sure that he is a guilty party we must, unless we can actually see him committing the crime, find that whenever he is present, and he has a chance, a burglary takes place.

Now in scientific investigation we can do what in ordinary life is not possible; we can take our burglar, arrange a set of suitable circumstances and see what happens and with what degree of regularity thefts occur. In the last four or five years something like this has been done on a large scale with cancer, and a large body of evidence is accumulating which suggests that, given suitable circumstances, chronic irritation will produce cancer with a fair degree of regularity, at least in some places. If it will do so in some places there is no reason to doubt that, under circumstances which for the moment we do not quite understand, it will do so in all the places where cancer is found.

That this is so has not yet been completely proved, but I think there is a good deal of evidence along this line. It has been known for a great number of years that certain skin cancers are constantly found in people whose occupations necessitate their skin being in contact with certain chemical irritants. For instance, the workers in shale oil are often afflicted with cancer of the skin. In the spinning industry, when reaching over to deal with the machinery, a place on the worker’s leg is always rubbing up against an oily spindle. This process goes on for years at the same spot, and these people are found frequently to get cancer, beginning at the irritated place. Some aniline dyes are excreted in the urine, and growths of the bladder are very frequent in aniline workers. In India, some native tribes carry little metal boxes containing charcoal next to their skin in order to warm themselves, and the warmed spot frequently becomes the seat of a malignant ulcer. Further, in chimney-sweeps, whose skin is always more or less impregnated with carbon, we find that cancer frequently develops in those places where the soot is difficult to wash completely away and often is not cleaned off for years at a time. Finally, we have the well-known examples of skin cancer among X-ray workers, and mouth-cancer in those who chew betel nut.