A guide to Cancer Statistics
Cancer affects all ages; however, it is predominately a disease that affects the elderly. The rate of cancer in any age-group rises continuously in both males and females from about the age of 30.
The statistics presented here fall into three groups: Incidence, Mortality and Survival. Incidence and Mortality can be reported in three ways:
1) Number: this is simply the number of cases cancer in an area and will depend on the population of that area and on the age structure of its population as well as on the underlying rate of cancer.
2) Crude rate per 100,000 population: this is the number of cases of cancer in an area divided by the population of that area. This measure takes account of the size of that population, but not its age structure; it tends to be higher in areas where the population is older when the underlying rate of cancer is not different. As age differences make it difficult to compare areas, crude rates are not reported here; age standardised rates are used in preference.
3) Age standardised rate per 100,000 population: this measure adjusts the crude rate according to the age structure of the population. It estimates what the cancer rate would be if the age structure of the population was the same as that of a standard population (based on the whole European population). As this measure takes account of both population size and age structure, it can be used to compare the rates in different areas. The graphs of age standardised rates show 95% lower and upper confidence limits (95% LCI and 95% UCI); these are the levels between which there is a 95% probability that the true rate of cancer will fall. These confidence limits become much wider as numbers become smaller, either when the area (and its population) is small, or when there are rare cancers with few cases.
Survival
Five-year relative survival rates of cancer patients diagnosed in 1981-2000 are shown. Relative survival, expressed as a percentage, is the ratio of the survival observed in a group of cancer patients to the survival that would be expected if they were subject to the same overall mortality rates as the general population.