The evaluation of cancer control measures.

The assessment of a screening procedure falls into two parts. The first is the development of a test and the establishment of criteria of specificity and sensitivity. The second stage is that of the application of the test to the general population, demanding attention to the natural history of the disease and to the usefulness and simplicity of the test itself. The decision to organize a screening programme has usually to be taken on the basis of incomplete information and in the setting of a population subjected to constant change. It is the hope of the Committee on Cancer Prevention and Detection of the UICC that the conclusions from the Symposium will prove helpful to all who face such decisions.