Colonoscopy for Colorectal Cancer Screening

Abstract

Colorectal cancer (CRC) is the second leading cause of cancer death in the United States. Many, if not most, cases arise from premalignant lesions (adenomas) which may be identified and removed prior to becoming frankly malignant. For over a decade, colonoscopy has been the preferred modality for both CRC screening and prevention in the US. Early reports suggested that colonoscopic screening imparted a 90% risk reduction for colorectal cancer. Subsequent studies showed that estimate to be overly optimistic. While still an outstanding CRC screening and detection tool, colonoscopy has several important limitations. Some of these limitations relate to the mechanics of the procedure such as the risk of colonic perforation, bleeding, adverse consequences of sedation, and the inability to detect all colonic polyps. Other limitations reflect issues with patient perception regarding colonoscopy which, at least in part, drive patient non-adherence to recommended testing. This review examines the literature to address several important issues. First, we analyze the effect of colonoscopy on CRC incidence and mortality. Second, we consider the patient-based, periprocedural, and intraprocedural factors which may limit colonoscopy as a screening modality. Third, we explore new techniques and technologies which may enhance the efficacy of colonoscopy for adenoma detection. Finally, we discuss the short and long-term future of colonoscopy for CRC screening and the factors which may affect this future.

Validation of a Real-Time PCR–Based Qualitative Assay for the Detection of Methylated SEPT9 DNA in Human Plasma

“…Increasing screening participation will increase the number of colonoscopy referrals. Although the number of unnecessary colonoscopies differs based on the choice of first-line screening methods, colonoscopy remains the current standard of care and carries a very low risk of adverse events (0.5%) (36 ).…”

Endoscopic mucosal resection and endoscopic submucosal dissection for colorectal lesions: A systematic review

“…CRC screening resulted in an increased diagnosis of a large number of colonic polyps (Jemal et al, 2010;Young and Womeldorph, 2013).…”

Screening Colonoscopy: Still the Best Choice, but for How Long?

“…First, colonoscopy is more expensive and timeconsuming than fecal immunochemical testing with or without added sigmoidoscopy. Second, even though subjects undergoing colonoscopy must ingest large volumes of polyethylene glycol or a similar laxative to prepare the mucosa for visualization, bowel preparation is inadequate in up to 25 % of patients at the time of their examination [6]. Poor bowel preparation can result in an incomplete examination, including inability to reach the cecum and overlooking some lesions.…”