Epidemiology of urinary bladder cancer: A review of selected literature

Abstract

In reviewing selected epidemiologic literature pertaining to cancer of the bladder, some of the major findings may be summarized as follows: 1. 1. A relatively small variation in mortality rates among different countries, with a generally sharp increase from young to old persons and an increasing mortality trend in a number of countries. Mortality rates are low for both sexes in Japan, and comparatively high in England and Wales, Scotland, Denmark and the white population of the United States. 2. 2. In the United States, a combination of factors have contributed to the apparent discrepancies between nearly stable death rates and rapidly rising morbidity rates for this disease among white males, a declining mortality but a steady incidence among white females, and a rise in both mortality and incidence rates for nonwhite males and females. The mortality risk is higher for nonwhites than for whites among young persons, but the reverse is true for older persons. 3. 3. The high male-female ratio is almost universal. Among U.S. males, both mortality and incidence rates are higher for whites than for nonwhites. Among females, a higher death rate occurs in the nonwhite population, whereas the incidence rate is practically the same for the two races. The mortality rate for the urinary organs is much lower among the Japanese, the American Indians, the Chinese or the Filipinos than that for the U.S. white or total population. 4. 4. Mortality rates are generally higher in the Northeastern, East North Central and the Pacific areas than in other parts of the country, and in metropolitan and urban areas than in nonmetropolitan and rural areas. 5. 5. A lower frequency of bladder malignancy is found among foreign than nativeborn white populations, particularly among females. In Israel, the age-specific mortality rate for the urinary organs is moderately lower among Oriental Jews than among Occidental Jews. Mortality rates seem to be slightly higher among white Protestant males and females than among persons of other faiths. There is evidence for elevated mortality from cancer of the urinary organs among persons who are single or not currently married, particularly among divorced males. 6. 6. No regular gradient has been observed between the risk of bladder cancer and the broad social classes. Workers in those industries concerned with certain chemical substances such as aniline, benzidine, α-naphthylamine or β-naphthylamine are found to have a high risk in this disease. 7. 7. A significant association between cigarette smoking and bladder malignancy has been observed in both retrospective and prospective studies. 8. 8. No significant evidence is found of a familial aggregation of this disease. Specific suggestions are made and discussed with respect to some possible areas of fruitful research.