A comparative epidemiologic study on geographic distributions of cancers of the lung and the large intestine in Japan.

To examine what kinds of factors could have caused the geographic variation observed in lung cancer morbidity in Japan, a correlation study was performed comparing various regional traits. The same study was also conducted on large intestinal cancer, aiming to distinguish the possible urban factors associated with both cancers. Lung cancer was highly correlated with industrialization-related factors such as localization of manufacturing industries, automobile traffic and air pollution, whereas colon cancer was correlated with the population density of workers in the tertiary industries such as services, trade and government. A multiple regression analysis could not detect any single factor with an exceptionally strong influence on either cancer. The present findings suggest that the hazardous environmental condition of urban areas has, to some extent, contributed to the recent increase of lung cancer cases in this country.