The conquest of cancer

by H. W. S. Wright

The greatest number of cases appears at or after fifty, and therefore at that age it behoves us, not to wait and see whether we shall get it or not, but to look and see that we have not got it, for of people who survive till the age of fifty, a great many more than ten per cent. die of cancer.

From the biological point of view cancer presents another interesting feature. It used to be generally stated by biologists that acquired characteristics cannot be transmitted. In cancer we see a cell taking on foreign characteristics in response to some environmental stimulus and transmitting these to its offspring until the organism from which it sprang is destroyed.

To sum up, the tissues from which cancer grows, in their normal process of repair tend to reproduce themselves more or less exactly, or if the injury is too gross, they are replaced by scar tissue; but when we reach the age at which their biological work is done, there is a tendency to atypical reproduction, in which an atypical cell continues to reproduce itself atypically and grows at the expense of the organism, eating into or eroding it as it enlarges, till it finally kills the host on which it preys.

This will serve as a general definition, but, if we wish to be a little more concrete, we must plunge for a while into the realms of pathology, in order to get a clearer idea of what cancer means.

Our body is made up of three layers of tissues; each of these has its separate function, and, within small limits, its own way of reacting to long continued injury. Early in our prenatal development, these three layers can be distinguished, and each of these later produces its own type of tissue, and under appropriate conditions, its own type of malignant tumour. From the outer and inner layers develop the cells which actually touch the outside world, that is to say, which cover the exterior of our body and provide our inner lining, or mucous membranes. From the inner layer is developed glands which are, so to speak, ingrowths from this layer, and it is the tumours arising from this latter tissue layer which mostly concern us now, and which are the cause of so much human suffering.

These Carcinomata, as they are called, all have something in common, alike from the point of view of their recognition, pathology and onset. They begin in some tissue which has previously been the seat of disease, usually some chronic inflammatory process which has been present for years, and which may have healed up and broken down many times. When this occurs on open surfaces, such as the tongue, intestinal mucous membrane, or lip, we can watch the gradual transformation of the disease from a simple chronic inflammatory process to that of a malignant growth.

Let us take, for instance, the case of cancer of the lip. We see an old man who for years has been smoking a clay pipe. The stem of the pipe gets shorter as the years go by, and consequently, as he smokes it, hotter and hotter. One day he notices that his lip is cracked, the crack being just on that part with which he habitually holds his pipe. If we were to look at this under the microscope we should just see that the mucous membrane was broken at this point. Perhaps he stops smoking for a day or two till his lip has healed, and then continues to smoke again. Soon, from force of habit, the pipe returns to its old comfortable spot; and again the lip cracks. This time it is not so painful, and takes longer to heal. This cracked lip may be present for years, and if, after some time, we were to look at it again under the microscope, we should see a very different kind of thing. All round the crack would be congregated thousands of white blood cells, trying vainly to assist the sore to heal, but, as well as this, we should notice that, in their efforts to bridge the gap of broken mucous membrane, the delicate epithelial cells which line our lips had increased in number and thickness. We might also see that they had a tendency to grow down to the deeper layers of the lip.

If we were to persuade our friend to give up his clay pipe and indulge in some other form of smoking, or even to have a few teeth extracted so that his pipe was more comfortable in some other position, the small ulcer would, given time and a little attention, heal up quite satisfactorily. But, with all the perversity of human nature, he will not; he only has a small sore: it doesn’t hurt him, or anyone else, so why should he worry?