Some Significant Features of Cancer Incidence in Japan

Much attention has been paid to occupational cancer, such as cancer of the skin developing among oil mechanics, lung cancer in miners of certain types, and bladder cancer as it occurs among workers with dyestuffs. Our study of the incidence of cancers of these types in Japan indicates that deviations from the usual are encountered. Comments on our findings are here recorded. Skin cancer Occupational skin cancer is extremely rare in Japan. Despite the fact that large numbers of men are engaged in the manufacture of lacquer-ware, these show no especially high incidence of cancer of the skin, it is even rare to find the development of a few warts. New lacquer is very irritating and causes an eruption of the skin, but this is readily cured. When the lacquer is applied to the skin of the mouse it appears to be devoid of carcinogenic action. Japan is one of the countries in which cotton manufacturing is an important industry, but a survey of the employees, mostly young women, in the spinning mills failed to reveal an unusually high incidence of skin cancer among the oilers. Japan also contains a great many plants engaged in gas, tar, and tar by-products manufacture , but here, again, the workmen show no especially high incidence of cancer of the skin. Obviously, such a condition demands that some explanation be offered. It may well be that the skin of the Japanese is more resistant , but another fact is not without importance. Japanese, as a general rule, bathe daily; the workmen in these industries habitually wear gloves while working, they frequently change their dothes which are often washed, and they daily take a very hot bath. At any rate, cancer of the skin is rare. In China, cancer of the penis is common, but this is not the case in Japan, a fact due, perhaps, to the less ample facilities for bathing among the Chinese, and to the added fact that among them phimosis is more general.