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6. How does cancer mortality in different countries compare?

The data available from Western Europe, Canada, Australia, and New Zealand indicate that cancer incidence and mortality in these areas are of the same order of magnitude as for the United States. Within this area of general agreement some differences exist. For men, the United States is near the lower end of the scale of cancer mortality among Western countries, while Finland and Scotland are near the upper end. For women, the disparity in rates among different countries is smaller and the United States occupies an intermediate position on the scale.

For most other areas of the world, the available statistics do not allow a precise judgment. However, it can be assumed that in most of Asia and Latin America, the risk of developing cancer or dying from it is less, since high mortality from other causes of death-particularly in the early part of life-leaves a smaller proportion of the population exposed to the risk of developing cancer. (Source: WHO; Epidemiological and Vital Statistics Report vol. 6, No. 12, December (1953).)

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NOTE. In this and subsequent figures, rates are age-adjusted, using the U.S. census population of 1950 as a standard, except where otherwise indicated.

7. How does the occurrence of cancer vary with age and sex?

Cancer incidence rates continue to rise to the end of the lifespan for both males and females. Between the ages of 20 and 55 the high incidence of cancers of the breast and reproductive system leads to a higher overall incidence of cancer among women than among men. At older ages the rates are higher for men than women, the excess becoming more marked with increasing age.

While these data are from U.S. experience, available evidence indicates that they are typical of experience in human populations generally. (Source: Dorn, H. F., and Cutler, S. J., "Morbidity From Cancer in the United States," Public Health Monograph No. 56, (1959).)

CANCER INCIDENCE RATES BY AGE AND SEX, 10 URBAN AREAS, UNITED STATES, 1947

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8. How does the occurrence of cancer vary by specific site?

If major site groups are ranked by level of cancer incidence, the digestive system is found to account for the largest number of cases of newly diagnosed cancer for either sex. The skin, genital organs, and respiratory system ranked next in incidence, in that order, for men; whereas for women the order of rank after the digestive system is genital organs, breast, and skin.

Ranking site groups by mortality rather than incidence leads to a similar order, except that skin cancer, which accounts for a large proportion of cases, is a relatively minor cause of death. If mortality for specific sites, rather than for major site groups, is considered, the leading sites for men were lung, stomach, and prostate, in that order, while for women the leading cancer sites were breast, large intestine, and uterus. (Sources: Incidence data are from Dorn, H. F., and Cutler, S. J., op. cit. Mortality data for the United States are published in the annual volumes of Vital Statistics of the United States.)

DISTRIBUTION OF NEW CANCER CASES BY SITE, 10 URBAN AREAS,
UNITED STATES, 1947

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9. Has the frequency of occurrence of cancer changed for specific sites?

While a number of minor changes in the occurrence of cancer are suggested by reported statistics for the United States, four changes are especially noteworthy.

There has been a large increase in the incidence and mortality for lung cancer among men. Between 1930 and 1955 mortality for this cause increased more than sevenfold, and indications are that it will rise even more. During the same period the reported mortality for leukemia more than doubled.

At the same time, mortality for cancer of the uterus decreased by half, but without a comparable change in incidence. Presumably this reflects an increasing chance of survival from this type of cancer, perhaps in response to earlier diagnosis and improved treatment. A decrease has occurred in mortality for stomach cancer, apparently resulting from a decreasing incidence of cancer of this site.

CHANGES IN MORTALITY FOR STOMACH CANCER, LEUKEMIA, LUNG CANCER, AND UTERINE CANCER, UNITED STATES, 1930-55

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