The monitoring of cancer occurrence provides fundamental baseline information for the development of research programs into the aetiology of the disease as well as for the planning and evaluation of public health interventions. Geographic and ethnic group comparisons, temporal trends and ecological studies can all provide important clues as to the causes of cancer. At the same time, incidence and mortality rates quantify the size of the problem in a given population and provide the basis for initiating cancer control measures and evaluating their effectiveness.
