ABSTRACT
Colorectal cancer is the second leading cause of cancer mortality and the fourth most commonly diagnosed cancer in the USA, where in 2001, we expect that 135 400 men and women will be diagnosed with colorectal cancer and that 56 700 people will die of this disease.1 We expect approximately 945 000 new cases of colorectal cancer and 492 000 deaths due to colorectal cancer worldwide.2 Colorectal cancer affects both men and women in approximately equal numbers. It may be possible to dramatically reduce the incidence and mortality of this cancer with the technology now available that can identify and remove precursor adenomatous polyps. Colonoscopy screening has the potential for a larger reduction in colorectal cancer mortality than that achieved by fecal occult blood testing or sigmoidoscopy screening.3 Recently, colonoscopy complication rates have become substantially reduced,4 fees for colonoscopy have been lowered, and the procedure has become more widely available in many countries. Cost analyses based on estimated effects suggest that screening colonoscopy every 10 years is as cost-effective as standard screening.5 Currently, we have evidence from observational studies that colonoscopic polypectomy can reduce colorectal cancer incidence. Stronger evidence for this preventative strategy will require a randomized controlled trial to assess whether a colonoscopy screening is efficacious and what is the magnitude and duration of the reduction in colorectal cancer incidence and mortality with the intervention of colonoscopy screening. The evidence for the prevention of colorectal cancer by colonoscopy is presented in this chapter.
