Physicians' perceptions of dysplasia and approaches to surveillance colonoscopy in ulcerative colitis

Colonoscopic biopsy surveillance to detect dysplasia, defined as a neoplastic change of the epithelium without invasion into the lamina propria, in patients with ulcerative colitis has become a widespread practice. We undertook a survey study to determine physicians' perceptions of, and approaches to, dysplasia surveillance colonoscopy in ulcerative colitis.

Members of two regional gastroenterology associations in the United States, including both academic and private practice-based gastroenterologists, and a group of senior gastroenterology trainees were surveyed by means of a written questionnaire. The questionnaires were distributed at three separate meetings of practicing gastroenterologists or trainees: 1) a Gastrointestinal pathology course for second-year gastroenterology fellows from training programs around the United States (February 1993, Los Angeles, CA); 2) a meeting of the Southern California Gastroenterology Society (March 1993, Los Angeles, CA); and 3) a meeting of the Pacific Northwest Gastroenterology Society (June 1993, Seattle, Washington). The percentages of all responses were tallied and analyzed for the group as a whole as well as by subgroup analysis. Understanding of the definition of dysplasia and specific practice techniques and approaches were the main outcomes sought.

Only 19% of respondents correctly identified the definition of dysplasia. More respondents (48%) correctly defined high grade dysplasia specifically compared with only 16% who correctly defined low grade dysplasia. The majority of respondents (69%) recommended colectomy when high grade dysplasia was diagnosed, yet nearly one-third of respondents pursued continued surveillance in this setting. Almost uniformly, respondents pursued continued surveillance and not colectomy when low grade dysplasia was diagnosed. Nearly one-half of the respondents thought that there was only < 20% chance of finding invasive cancer in patients with preoperative diagnoses of high grade dysplasia. On average, respondents performed surveillance colonoscopy every 1-2 yr and took an average of three biopsies per site, at approximately eight sites in the colon, and most respondents confidently relied on their local pathologist at making the diagnosis. There were, however, wide variations in the practice of dysplasia surveillance.

The majority of respondents did not know the definition of dysplasia, and most viewed it as a preneoplastic lesion. Furthermore, there was a lack of appreciation that the difference between low grade and high grade dysplasia is one of degree or severity of neoplastic change and for the likelihood of finding invasive cancer at surgery if there is only a diagnosis of dysplasia preoperatively. Dysplasia surveillance colonoscopy in ulcerative colitis is not a well standardized, clearly understood screening tool, and continued education of the gastroenterology community regarding its outcomes and pitfalls is needed.