[What is epidemiology and what is cancer epidemiology?]

We have the world's oldest cancer registry in Denmark. We also have a cancer society that has invested substantial funds in epidemiology, which have been well used by highly skilled cancer epidemiologists. This is the formula for success. Cancer epidemiology, which is now conducted at the highest international level in Denmark, is a subdiscipline within epidemiology, and most of its activities are related to public health problems. Clinical cancer epidemiology is, however, a field which will grow in the next decades. Cancer epidemiology requires data of good quality and access to data for use in research. New important results will emerge if trajectories of cancer occurrence can be studied in a lifelong perspective. Research involving genetic factors will also open up new avenues for studies, but it will not replace research, whose starting point is the population's social conditions, their lifestyle, and environmental influences.