Population-based colorectal cancer screening by colonoscopy or CT colonography

Abstract

In 1968 at request of the World Health Organization (WHO), Wilson and Jungner defined 10 criteria for informed population-based screening.(1) In subsequent years, these criteria have been reevaluated and revised several times. In their most recent version, they can be summarized as follows: screening has to aim at an important health issue, and it has to result in substantial health gain or lead to other healthcare benefits. Besides, the method of screening must be reliable and valid. Finally, participation in screening has to be based on informed choice and must be completely voluntarily. Colorectal cancer can be considered an important healthcare problem. Colorectal cancer is the third most common cancer worldwide and the second leading cause of cancer-related mortality.(2) The lifetime risk in the US population is 5%-6% without screening(3), which is similar in the Netherlands.(4) More than 400 000 persons are diagnosed with colorectal cancer each year in Europe.(5) The prognosis of CRC depends on the stage at the time of diagnosis; in the Netherlands, the 5-year-survival rate of stage I CRC is 94% compared to 8% for stage IV.(4) Several studies have shown that colorectal cancer screening is effective in the average risk population.(6-8) Besides, screening for CRC is thought to be cost-effective.(9) Screening can be performed with a range of different methods and strategies. Available methods for colorectal-cancer screening fall into two broad categories; stool tests (guaiac fecal occult blood test (gFOBT), fecal immunochemical test (FIT) and DNA tests) and structural examinations (flexible sigmoidoscopy, colonoscopy, and computed tomographic colonography)