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The promises and perils of nurse-led flexible sigmoidoscopy screening.

Public awareness of the need for colorectal cancer (CRC) screening is growing thanks to media personalities such as Katie Couric (1), and other publicity drives. Many Canadian provinces have responded to this by developing CRC screening programs. The model most provinces have considered is the fecal occult blood test (FOBT), in line with recommendations by Health Canada (2). These initiatives are welcomed, although FOBTs only reduce CRC mortality by 15% to 25%, and screening programs that prevent CRC, as well as detect the disease early, may be of greater benefit. The current alternative screening modalities are flexible sigmoidoscopy (FS) and colonoscopy (3). FS detects adenomatous polyps and malignancy up to the splenic flexure, where two-thirds of all CRCs are located. Therefore, the removal of adenomatous polyps should reduce the incidence of CRC. FS is currently being evaluated in three randomized controlled trials (RCTs) (4–6) assessing almost 360,000 patients. The stage that CRC is detected is earlier than seen with symptomatic cancers (4–6). The impact of FS on CRC incidence and mortality during follow-up will be reported in the near future. The advantage of FS is that the bowel preparation required is less rigorous, and the procedure is easier and quicker to perform than a colonoscopy, with no sedation required. On the other hand, FS will potentially miss right-sided lesions but colonoscopy views the whole colon; thus, colonoscopy is probably the most effective strategy. However, the cost of offering colonoscopy as a screening program is prohibitive in the Canadian health care setting. FS would also be difficult to deliver in Canada because there are insufficient clinicians to provide the service (7) and their time would be expensive. FS is relatively straightforward to perform, and if a less expensive section of the health care workforce could deliver this service then FS could be a viable screening option.