DISCOVERIES IN CANCER RESEARCH
THE armies of science are•closing around that elusive enemy, cancer ; and every day we become more confident of victory. The most spectacular success belongs to Dr. William Gye and Mr. J. E. Barnard, of the National Institute for Medical Research. It seems certain that they have discovered the organism which causes cancer. It is no marvel that the germ was hard to find ; it is so small that no microscope is powerful enough to show it, no filter fine enough to keep it back. Mr. Barnard has invented an apparatus by which it can be seen and photographed ; not directly, of course, but rather as motes of dust are seen in a ray of light. Dr. Gye has verified his results experimentally, and has been able to discover the conditions under which cancer occurs.
This success raises no immediate hopes of a cure. We have known the cause of tuberculosis for twenty-five years, and no cure has been found. But it is necessary to go into what may be called the classical theory of cancer before we see the difficulties in the way. By itself the cancer organism is harmless. It can be injected into the body without evil results ; for the germs must settle them- selves in the cells of the body before disease sets in, and an ordinary healthy cell is capable of keeping them at bay. But if anything should happen to make a breach in the walls of the cell, then the germ can creep in and dwell secure from all ordinary attacks. Once in, it appears to excite the cell into rebellion against the body. The cell forgets its allegiance, multiplies without restraint, feeds upon the body without working for its wages. In his excellent book, New Cancer Facts (Bodley Head), Mr. David Masters puts the result forcibly and well :— "This cell, as it were, runs amuck and proclaims its independence. It creates more and more cells which live and feed on the body after the fashion of parasites ; yet they are the same cells as those of the body, they are part of the body, and because of this the body has no defence against them. How can the body stop its own cells from growing? . . . They are able to penetrate the tissue and migrate to a part of the body perhaps far removed from their original starting-point. Here they will again multiply and produce a second. ary growth, but no matter where this growth occurs, the cancer cells are a more or less exact reproduction of the cells which first became cancerous."
It is because of the mobility of these cancer cells, carried about by the blood stream to all parts of the body, that surgical operations may so easily fail. It is because the germ is so snugly hidden in the cell that we cannot be confident of killing it by anti-toxins. But there is more cause for hope than for despondency. After all, the rebellious cell is degenerate ; and radium treatment has shown that it can be killed by an attack which will leave the healthier cells around it unharmed. There arc, so far, several important triumphs. The technique of operation and the technique of radium treatment are both progressing rapidly. The knowledge of the con- ditions which leave the cell open to attack is almost complete.
Dr. Gye has shown that if an extract of bruised tissue is injected with the virus of cancer, then cancer will inevitably follow. But the common belief that there has always been a bruise before cancer sets in is not entirely true. It appears from the researches of Dr. Louis Sambon that cancer can follow upon other condi- tions, similar in effect, no doubt, but to be looked for in a strange quarter. Mr. Masters devotes most of his space to Dr. Sambon's work. He worked first in Italian villages where the death-rate from cancer was known to be high. He found definite evidence for the existence of cancer- houses and cancer-streets. Often the cases were confined to one quarter of a village, and the rest of the village was free. He was first put upon the track of this discovery by noticing the almost invariable presence in these cancer- houses of meal-worms, beetles, cockroaches, mice and rats. All signs seemed to lead him to the conclusion that it was a parasite that spread the infection. When he had examined animals with cancer, and human beings with cancer, and found, too often for coincidence, the presence of a small colourless parasitic worm, he was convinced that he had hit upon one of the root causes. There is a small parasite which starts its life in the cock- roach and completes its development in the rat : if it is to grow beyond the larval stage it must be swallowed in the body of an insect by some animal. And it was this parasite which seemed to cause most of the trouble. Dr. Sambon concluded that it carried the infection, and predisposed the cell to conquest by the germ.
Dr. Sambon's researches do not necessarily conflict with those of Dr. Gye and Mr. Barnard. It may be that the parasite he has connected with cancer is able to produce exactly the conditions which Dr. Gye produced with bruised tissue and virus. If his work is confirmed, we have another terrible indictment against that bane and destroyer, the rat. It would be comparatively easy to reduce the hordes of rats and mice and cockroaches almost to vanishing point, if only energetic and co- ordinated action were undertaken. But it is hard to get that magnificent creature man to realize that he is so much at the mercy of these apparently insignificant wretches.
The main hope of success in the fight against cancer comes from the way in which various lines of research are contributing towards a solution ; perhaps in the end we shall be saved more by quick-wittedness and versatility in our attacks than by a single panacea. But our chances have never seemed so bright before : the devotion and whole-heartedness with which our institutes and our private workers have set themselves to their task will surely be rewarded.
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