POPULATION SCREENING FOR COLORECTAL DISEASE: A MUST DO?

Colorectal cancer is the second commonest cause of cancer death in the Western world and the median five year survival from this terrible disease remains at approximately 40%. In the UK approximately one third of cases still present as emergencies with intestinal obstruction or perforation

One method of reducing the mortality of this disease is through earlier diagnosis but the symptoms and signs of bowel cancer are often non-specific and therefore earlier diagnosis is unlikely to occur through increased awareness or patient education alone.

Colorectal cancer is an ideal disease for population screening: it is common, has a well recognised premalignant precursor lesion (the adenoma), and treatment of the premalignant condition reduces the risk of cancer.¹ Several case control studies and four randomised trials have shown that population screening for colorectal cancer reduces disease specific mortality. One large trial has also shown that population screening can reduce the incidence of this disease.² Overall, the cost effectiveness of screening for colorectal cancer compares favourably with other cancer screening strategies (that is, breast and cervical).³

The case for screening for colorectal cancer is increasingly compelling and with the launch of the National Pilots in Scotland and Warwickshire the politicians appeared convinced too! Over 12 months later, with the pilots nearing completion and preliminary data from the MRC Flexible Sigmoidoscopy study, another difficult decision looms.

WHICH SCREENING TEST SHOULD WE USE?

The debate over which screening test to use encapsulates some of the major issues in the provision of healthcare in the 21st century (especially in the National Health Service). Major technological advances are occurring at an increasing rate, but manpower and finance for today’s technology are severely limited.

Although there are many potential screening tests for colorectal cancer, ones which are serious contenders for population screening are stool based tests or endoscopy. Of these, only …