Assessment of screening for cancer

Screening has a relevant role in and is likely to become an increasingly important instrument for cancer control in the near future. This overview summarizes some of the available evidence on the issue. Some of the opinions are well established. The apparent absence of consensus on other issues should be critically evaluated, too, because the evidence on some procedures is substantially more convincing than that on others. High costs, low compliance, poor curability, and substantial false positive rates, in a disease as relatively rare as cancer, often counterbalance in practice the theoretical benefits of diagnostic anticipation. In screening as well as in treatment for cancer, it is unlikely that major technical breakthroughs will occur in the near future. The evaluation of whether the benefits likely to be achieved by the screening program outweigh its disadvantages by a sufficient margin, therefore, should rely on large and carefully planned controlled studies.