ABSTRACT
Screening is a process aimed at the presumptive identification of unrecognized disease, in order to improve the outcome by making an early diagnosis. It uses procedures that can be applied rapidly and economically to a specific population. Screening tests are not usually diagnostic, and further tests and examinations are required to establish the diagnosis. This chapter discusses the requirements for a screening programme, and the main characteristics of the screening test. Some of the screening programmes are: breast cancer screening, cervical cancer screening, and colorectal cancer screening. Primary screening of colorectal cancer is by means of a faecal occult blood-testing kit sent to patients every 2 years after the age of 50 years. If the result is positive on a repeat test, the patient is invited for a further procedure such as flexible sigmoidoscopy, colonoscopy or double-contrast barium enema, depending on local provision. Patients with mammographic abnormalities are referred to a breast specialist for clinical examination and further investigations.
