Introduction

Cancer screening is one of the great controversies of modern medicine. The controversy is bound to increase as our knowledge of genetics improves. At the interface between public health and specialist care, its economics creates tensions between professional groups, politicians and the public: a screening test may be cheap, but applying it to a population (with rigorous quality control and effective processing of patients with abnormal results) creates a large workload and therefore sizeable cost. Screening can also have profound psychological effects on individuals with false-positive results who require investigation but are eventually found not to have cancer. Unless screening can be shown to reduce mortality rates from a specific cancer, the money used is often better spent on improving care, and this has led to a disparity in screening recommendations between countries. The human genome project is likely to provide new approaches to cancer-risk assessment and will bring new challenges to this complex area.

There is a contrast between extensive and largely uncritical public support for screening, and the very real difficulties in organising effective programmes. There has been one great success – cervical cancer screening on a population basis. This programme has been able to reduce incidence and mortality in some developed countries with particular success in the UK and Scandinavia. In addition, there has been some success from mammography programmes.