P571 Frequency and risk factors of advanced neoplasia in Korean IBD patients with Low Grade Dysplasia in previous surveillance

Abstract

Background There are insufficient studies on clinical outcome after surveillance of low grade dysplasia (LGD) in patients with inflammatory bowel disease (IBD). We aimed to evaluate the clinical feature, frequency and risk factors of advanced neoplasia in IBD patients after diagnosis of LGD Methods From 2003 to 2020, medical records of 166 IBD patients from 6 university hospitals in Korea were reviewed retrospectively. All of the patients were diagnosed as LGD in surveillance. Patents’ baseline characteristics, disease status, polyp characteristics and treatment were evaluated. The frequency and risk factors of advanced neoplasia were also analyzed. Results Disease duration was 11.47 years (7.85-14.50), and follow-up duration was 3.74 years (1.95-7.58). Colitis associated LGD was noted in 56 cases (33.7%), Advanced neoplasia developed in 12 cases (6 large LGD, 3 tubulovillous adenoma, 3 high grade dysplasia) and all the cases developed from UC. Patients with advanced neoplasia had significantly higher Mayo score and colitis-related dysplasia were more common than sporadic lesions (83.3% vs. 29.9%; P<0.001). In multivariate analysis, colitis-associated LGD significantly increased the risk of developing advanced neoplasia (Odds ratio [OR], 10.516; 95% confidence interval [CI], 2.064-53.577; P=0.005). Among patients with colitis-associated lesions, a significant risk factor for advanced neoplasia was a history of LGD (OR, 9.429; 95% CI, 1.330-66.863; P=0.025). Conclusion Advanced neoplasia developed in 7.2% of IBD patients with LGD. Because most of advanced neoplasia developed from colitis-associated lesions, more careful examination is suggested in patients with colitis -associated LGD, especially with previous history, in surveillance colonoscopy.