Adherence to colorectal polyp surveillance guidelines: is there a 'scope' to increase the opportunities for screening?

Colorectal polyps are usually asymptomatic and are found opportunistically. Individuals with adenomata are at increased risk for cancer and therefore guidelines exist for surveillance of these lesions including those of the British Society of Gastroenterology (BSG). Deviation from these guidelines is common and increases the workload of endoscopy. We examined those individuals waiting for endoscopy for polyp surveillance to see whether strict adherence to BSG guidelines could facilitate opportunities for screening. A total of 413 patients with earlier colonic polyps were examined, of whom 50 patients were excluded based on having alternative indications for surveillance, 179 (49.3%) were appropriately scheduled for surveillance and 184 patients (55.9%) were scheduled incorrectly. Seventy-nine patients (30%) could have been discharged; of these, 59 had hyperplastic polyps. Of the remaining 105 inappropriate triages under surveillance at the wrong interval, seven patients were scheduled for too infrequent surveillance and 98 were too frequent. A total of 284 patients with adenomatous polyps were under surveillance of whom 11 patients (3.8%) were in the high-risk category and all were appropriately scheduled, and 75 patients (26.4%) were in the intermediate-risk category, of whom 48 were appropriately scheduled, 20 were incorrectly triaged as high risk and seven were triaged as low risk. A total of 198 (69.7%) patients were in the low-risk category, 117 of these were correctly triaged, 15 were incorrectly triaged as high risk and 66 were classified as intermediate risk. Over a five-year period, 318 unnecessary colonoscopies are being performed. On the basis of the data obtained from a population-based colorectal screening programme using immunohistochemical-faecal occult blood testing in our department another 1516 patients could be screened annually without requiring any additional endoscopy resources, if strict adherence to guidelines was assured.