VAGARIES IN INCIDENCE

Evening Post, Volume CXIII, Issue 3, 5 January 1932, Page 6

VAGARIES IN INCIDENCE

SOME DEDUCTIONS

NO DRAMATIC ADVANCE

(From "Tho Post's" Representative.) LONDON, 26th November. Summarising the report of the Imperial Cancer Research Fund at a meeting of the general committe, Sir Humphry Kollestou, the ' chairman of the executive committee, referred to Dr. Cramer's papers on susceptibility to cancer as applied to the important subject of the incidence of cancer of the stomach in this and several European countries. Although the total incidence of cancov in males, he said, was approximately the same in these different communities, only 25 per cent, of male deaths in England and Wales were duo to cancer of the stomach, whereas the proportion in the Europe.au countries from which accurate statistics were available was as high as 50 per cent, or more. This discrepancy was accentuated when the incidence in different social classes in the same country was compared. In England and Wales, as Dr. Stevenson showed, cancer of the stomach and upper alimentary tract was more common in lower social classes, the incidence of, the lower alimentary tract being the same for all classes. In Bavaria, with double the frequency of gastric cancer in the whole male population as compared, with England and Wales, the proportion in the working classes was from 60-70 per cent.-of total cancer deaths. From the analogy which these figures presented to the facts of the incidence of occupational cancer, the conclusion was drawn that the important factors in producing this remarkable result were external, bound up with the habits of the social levels involved and avoidable. As these vagaries in organ incidence of cancer rid not produce corresponding fluctuations in the total incidence of the disease in the populations under review, t.iC plus for ono organ was reflected in a minus for "the others. Thus, according to the statistics, cancer of the tongue was nine times more frequent in England than in Bavaria. It was as if the majority of cancer deathsfell on a susceptible fraction of the population (roughly 10 per cent.), the members of which responded relatively easily by manifesting cancerous growths to forms of chronic irritation to which the whole population was exposed to much the same extent. Susceptiblo individuals fortunate enough to escape tho full brunt of these irritations might escape, and conversely, excessive irritation might lead to cancer development in a small proportion of individuals, constitutionally unsusceptible. ACTION OF DYESTUFFS. The possibility that dyestuffs, metallic colloids, and other . chemotherapeutic agente might -influence tho growth of cancer indirectly through an action on tho organism of the host, had led Dr. Lu'dford to investigate the action of these substances on the resistance to transplantable tumours. In effect it had been found that one of the carcinoma strains which in. untreated animals grew only temporarily and then regressed, could be made to grow progressively by treating the mice boaring it with trypan blue or metallic colloid. , The immunity to transplantable growths, which could be induced by preparatory injection of emulsions of embryonic tissues, could be broken down by similar injections of dyestuffs or colloidal metals. The doses necessary to produce this result must be large, approximately the limits tolerated by the animals. These results emphasised the dangers of over-dosage in the treatment of cancer with toxic colloids, in that the natural reactions of the body might bo so modified as to accelerate the progress of the disease. The converse process of raising, instead of lowering, the natural resistance to such an extent as to retard or arrest the growth of cancer, had so far not been attained in these experiments. It remained a fascinating aspiration. The report by the director, Dr. J. | A. Murray, after referring to the studies and reports on the subject, con- ! eludes:— _.'' This discussion, taken in its entirety, leads to the conclusion that we are not yet in possession of such knowledge of the properties of the cancer cells as would indicate clearly the directions in which a rational specific therapy of cancer should proceed. It is perhaps not too much to hope that these observations may help the lay and general medical public to appreciate the j conservative and cautious attitude j which those engaged in cancer research preserve towards the recurring extravagant announcements of new methods of treatment for cancer. In particular, we should recommend that tho .^layman should finally discard his attitude towards this medical and biological problem as a gamble, where success is equally likely to fall to the ignorant as to the instructed. "This betrays a profoundly mistaken view of the nature of the cancer problem. Thirty years of cancer research have revealed that this problem possesses a complexity which was quite unexpected. The knowledge which has thus been gained justifies the hope that perhaps progress in the direction of an efficient cancer prophylaxis is possible. An advance along such lines is, however, not dramatic or sensational. But whatever the future of the cancer problem will be, it is certain that it will not yii)d- to the sound of a trumpet."