High-Grade Dysplasia in Inflammatory Bowel Disease: Indication for Colectomy

BACKGROUND: Patients with inflammatory bowel disease have an increased risk of colorectal cancer and are recommended to undergo increased surveillance compared to the general population. Currently, inadequate evidence exists to guide management of colonic dysplasia discovered during screening of inflammatory bowel disease patients. OBJECTIVE: The goal of this study was to determine the risk of colorectal cancer in patients with ulcerative colitis or Crohn's disease with dysplasia on colonoscopy.DESIGN: This was a retrospective study.SETTING: This study was conducted at a high-volume, quaternary referral center with an inflammatory bowel disease program.PATIENTS: Patients with a diagnosis of inflammatory bowel disease with colonoscopy within 6 months of colectomy were included.MAIN OUTCOME MEASURES: The primary outcome measures included finding of colorectal cancer at time of colectomy.RESULTS: There were 621 patients, 233 with ulcerative colitis and 388 with Crohn's disease. Of ulcerative colitis patients, 25 had low-grade dysplasia on colonoscopy with 1 (4%) found to have colorectal cancer at colectomy. High-grade dysplasia was noted preoperatively in 14 and colorectal cancer was found in 4 (29%) after colectomy. Compared to no dysplasia, low-grade dysplasia did not increase the risk of colorectal cancer (OR 1.98, p = 0.47), but high-grade dysplasia had an increased risk (OR 19.0, p < 0.001) of colorectal cancer. For the 7 patients with Crohn's disease and low-grade dysplasia, colorectal cancer was found in 1 patient (14%) at colectomy. Highgrade dysplasia was noted preoperatively in 4 patients with Crohn's Disease, and colorectal cancer was found in 3 patients (75%) after colectomy. Compared to no dysplasia, low-grade dysplasia did not increase the risk of colorectal cancer (OR 12.4, p = 0.88), but high-grade dysplasia did increase the risk of colorectal cancer (OR 223.2, p < 0.001).LIMITATIONS: This study was limited by its retrospective review.CONCLUSION: In both ulcerative colitis and Crohn's disease, low-grade dysplasia was not associated with colorectal cancer. High-grade dysplasia was associated with an increased risk of colorectal cancer at time of colectomy. While continued surveillance may be appropriate for low-grade dysplasia, high-grade dysplasia necessitates surgical resection given the high likelihood of colorectal cancer.