ABSTRACT
This chapter considers the principles of screening, and looks at colorectal cancer as a suitable target for screening. It examines the evidence for the major screening modalities, cost-effectiveness issues, and future approaches using novel methods. In screening cost-effectiveness can be calculated in purely monetary terms but it has to be remembered that screening produces morbidity both psychological and physical, and it is important that this is also factored into the equation when a cost-benefit analysis is carried out. An interesting side effect of the Nottingham screening study has been highlighted by the observation that in the control group the percentage of patients presenting with favorable stage rectal cancer increased from 9% in the first half of the recruitment to 28% in the second half. There are various methods of testing for blood in the feces but the method that has been employed in all the published population-based screening trials involves the use of guaiac.
