CAUSES OF CANCER.

Otago Daily Times, Issue 20256, 15 November 1927, Page 3

CAUSES OF CANCER.

RACIAL INCIDENCE. INTERESTING FIGURES. INDIVIDUAL CONDITION. Various things have been set down at various times as causes of cancer. The nature of the soil, climatic conditions, modern -ways of living, faulty diet, contagion, heredity—all these have had their turn, and have one by one been abandoned. In the same neighbourhood some groups of people are not susceptible to cancer, and others are severely attacked. As for diet, some rural populations which hardly ever taste meat are more liable to cancer than the population of towns where preserved and over-rich foods are largely consumed. When all is said and done, the most that can be affirmed is that cancer is due to some physiological conditions of the individual. Developing this idea, a writer in the French newspaper LTllustration of May 28 asks whether such a physiological condition, or such susceptibility, may not vary according to the various racial stocks —Nordic, Alpine, and so forth—and cites in this connection an interesting report on this subject, issued through the League of Nations by Dr Eugene Pittarcl, of the University of Geneva. AN ANTHROPOLOGICAL ASPECT. “ Why, in the obscurity that surrounds us," says the writer (M. Noells Roger), “ is no attempt made to find out whether cancer attacks every race in the same proportion? Such a question can only be answered by anthropology. And it is an anthropologist who, for the first time, has 'asked it. Doctor Pittard said to himself that if attempts to classify the geographical incidence of cancer had failed it was because only countries and nationalities had been taken into account, and investigations had neglected to observe that a nationality, formed as it was by a scries of historical events, a blending together ol traditions, often includes diverse races A Frenchman of Lille does not belong to the same ethnic group as a Frenchman of Marseilles or a Frenchman of the central provinces. “ Pasteur has proved that certain kinds of animals react in different ways to the nreeence of noxious microbes. Algerian sheep, for example, are immune against the anthrax, which is deadly to the sheep of France. Why should not such differences exist between human races? “ Certain historical documents, forgotten or not regarded, and various observations of mission doctors and doctors in the colonies, reveal, when they are sought out and co-ordinated, some curious facts. Thus, it has been known for some time that black races are barely susceptible to yellow fever, from which the whites die like flies. Also, mulattos are spared only in proportion as they have less of white blood. The American doctor Nott said that a quart of negro blood was a better protection from yellow fever than vaccine was from smallpox. Thus the physiological disposition of the black races is seen to be different from that of the whites. Mixing of blood *by disturbing this internal stale, makes half-breeds liable to contract a disease which was unknown to their ancestral race. Such facts explain why certain native populations have been almost exterminated by diseases brought to their country by . white men—diseases whose virulenae was increased tenfold because they folnd favourable material in which to breed. “ The white races also react diversely among themselves in contact with the same infections. It is common knowledge that Englishmen suffer a form of scarlet fever much more serious than that which attacks Frenchmen. The English, besides, are more subject to epidemics of this fever. On the other hand, Englishmen are less liable to collapse under an operation than are Frenchmen. Velpeau has, in fact, gone so far as to say that English flesh is not the same as French flesh.” The study of cancer in its race distribution, the writer goes on, presents some great difficulties. “It is necessary to seek out anthropological and medical records. Precise statistics are not easily obtained; and the ethnical composition of each country is far from agreed upon. In the course of his inquiries, however, Pittard has succeeded in arriving at a number of provisional conclusions. NEGROES NEARLY IMMUNE. “ For example, he has established that African negroes are hardly ever touched by cancer. It is the same with American Indians; while half-breed Indians and mulattos are attacked almost in the same proportion as white people living in the same districts. He finds that the different racial groups in Europe show very various reactions to the scourge. Between the Nordic type, which seems particularly susceptible, and the Ibero-insular, which appears to be almost Immune, there is a whole series of gradations.” M. Roger goes on to give details of the report issued through the League of Nations:—“A glance at a map showing the distribution of races in Europe and at the collected figures representing the average mortality from cancer in each country will show immediately that the variations in the figures coincide in great part with racial variations. . . . The countries inhabited largely by Nordic peoples seem to be those most severely attacked by cancer; while the Dinaric race seems to have lowered the average mortality in every region into which it has penetrated. The Alpine race -'pays a heavy tribute to cancer—not so heavy, however, as that which oppresses the Nordics. The Mediterranean stock is fortunate in being only slightly liable to the disease. “ It is instructive to study in detail the statistics for France and Italy, which deal with a number of races localised in fairly well-marked regions. Northern Italy, inhabited in great part by Alpine stock, is twice as much subject to cancer as Southern Italy, where the population is made up of the Mediterranean race. As soon as the line between Ancona and Rome is crossed the percentage of mortality drops abruptly. For Northern Italy, including Lombardy, Venetia, Emilia, and Piedmont, the average number of deaths from cancer varies between 14 and 31.3 for every 10,000 inhabitants. Of the four provinces mentioned Venetia is by far the least afflicted, an advance which she owes, apparently, to the presence of the Dinaric peoples. For Southern Italy the average varies between 11.1 and 22.7. In regions where the Mediterranean stock is most homageneous, such as Sardinia, Calabria, and Sicily, the death rate from cancer is lowest. The average for Sardinia is 11.1 for every 10,000 inhabitants.” The report goes on to analyse the figures for France, showing that the mortality becomes lower as one proceeds from north to south, examining successively sectors occupied by Nordic, Alpine, and Iberoinstilar races.