[20 years of cancer epidemiology. The clinician's viewpoint]

The future of cancer epidemiology remains wide open because of the slow progress in reducing mortality. Currently large scale screening is only conducted for cancer of the breast and cervix. Cancer of the colon is in the research stage. For all the other cancers, progress in prevention should result both from a better understanding of the causes and from more active participation by health care workers and the general population once risk factors have been clearly identified. Finally, it is important not to assess progress in therapeutics on the single criteria of long-term survival since one- or two- year remissions are important in terms of human life and may be the first signs of more durable progress in the future.