Cancer screening

“Screening is the systematic application of a test or inquiry, to identify individuals at sufficient risk of a specific disorder to benefit from further investigation or direct preventive action, among persons who have not sought medical attention on account of symptoms of that disorder.”1

Early detection and intervention is intuitively attractive, particularly for cancer when the consequences of disease may be serious and it seems obvious that early detection must be beneficial. Wilson and Jungner in 19682 proposed a set of criteria for assessing whether screening is worthwhile and their carefully reasoned and considered approach has served public health well in the following decades. Now, with several decades of screening experience to draw on, we propose the following criteria (1 to 3 below) need to be considered in assessing whether screening is worthwhile. In addition one further, rapidly developing issue (4 below) needs urgent debate and research. These points are identified below and then briefly discussed.

Cancer screening programmes should no longer be introduced without evidence from randomised trials demonstrating a mortality benefit or a quality of life benefit (for example, need for less invasive treatment)

The extent of inconsequential disease that will be generated by the screening programme should be estimated and carefully considered before widespread introduction of screening

The benefit (demonstrated by trials) should be weighed against the harms of screening to assess whether there is likely to be a net benefit from screening before widespread introduction of screening

If screening is introduced, potential participants in the screening programme should be given information that allows them to weigh up the probable benefit and harms, using their own values and preferences