Surveillance for dysplasia in patients with inflammatory bowel disease: A national survey of colonoscopic practice in New Zealand

BACKGROUND: Patients with chronic ulcerative colitis and Crohn's colitis have an increased risk of colorectal cancer. Because of this, surveillance colonoscopy is practiced. AIMS: We aimed to describe the practice of surveillance colonoscopy in New Zealand, with comparison among specialties, and with practice internationally. SUBJECTS: New Zealand colonoscopists (both physicians and surgeons) looking after patients with inflammatory bowel disease were surveyed to evaluate attitudes about surveillance colonoscopy and ways in which colonoscopy results are interpreted. METHODS: A postal survey assessed the colonoscopist's understanding of how and why surveillance colonoscopy is undertaken and their interpretation of the results from such evaluations. RESULTS: Of the 196 physicians and surgeons surveyed, 180 responded (92 percent). Sixty responses were excluded. Only 24 of 120 respondents (20 percent) correctly defined dysplasia. The median number of biopsies taken at colonoscopy was 17. Eighty of 120 (67 percent) and 77 of 120 (64 percent) doctors underestimate the risk of invasive malignancy if low-grade or high-grade dysplasia, respectively, is identified. The colectomy referral rate for dysplasia-associated lesion or mass was 115/ 120 (96 percent); that for high-grade dysplasia was 110/120 (92 percent); and that for low-grade dysplasia was 26/120 (22 percent). Thirty of 120 (25 percent) doctors offer patients the option of colectomy after 20 years of colitis. Seventy of 120 (58 percent) doctors sought the opinion of a second pathologist if dysplasia was found. There were differences in responses between specialist groups, with colorectal surgeons most likely to correctly define dysplasia and appreciate the significance of low-grade dysplasia. CONCLUSIONS: Many New Zealand colonoscopists have a poor understanding of the definition and importance of dysplasia associated with colitis. Although colectomy referral rates are higher in this study than in similar studies, low-grade dysplasia is often not referred for colectomy. Improved education may improve surveillance practice.