P265 Clinical characteristics and oncologic outcomes in patients with colorectal cancer complicating ulcerative colitis: a single-institution experience

Methods: We reviewed magnifying colonoscopic findings in 30 patients with quiescent UC who achieved complete MH (Endoscopic subscore of Mayo 0) by conventional colonoscopy. All patients performed magnifying observation using spraying with 0.1% indigo carmine dye solution after conventional colonoscopy. According to the fine network and cryptal pit patterns of colonic mucosa, we classified magnifying colonoscopic findings into four types (magnifying subscore 0 3); 0, the surface structures similar to normal colonic mucosa; 1, the disarray of fine network or cryptal pit patterns were observed; 2, the abnormal surface structures, such as fusion or disruption of fine network patterns and loss of cryptal pit patterns were observed; 3, the fine network or cryptal pit patterns were completely disappeared. We examined: (1) the proportion of patients without clinical relapse (magnifying subscore 0 or 1 group vs subscore 2 or 3 group); (2) the patients’ characteristics (age, gender, disease phenotype, extent disease, and medications) between our magnifying colonoscopic classifications. Disease activity was evaluated using a clinical activity index of Rachmilewitz (CAI), and clinical remission was defined as CAI score of 4 or more. Results: The distribution of magnifying colonoscopic findings was as follows; 10 (subscore 0), 9 (subscore 1), 8 (subscore 2) and 3 (subscore 3). The proportion of patients with relapsefree in magnifying subscore 0 or 1 group was significantly higher than that in magnifying subscore 2 or 3 group (89.5% vs 36.4% at 12 months after magnifying chromoendoscopy, log-rank test p < 0.01). The patients in magnifying subscore 2 or 3 group significantly received more cumulative dose of prednisolone compared with those in magnifying subscore 0 or 1 group (485.0±104.9 vs 77.6±47.4mg/month), however, there was no significant correlation between magnifying subscore and other clinical parameters. Conclusions: Magnifying colonoscopy can provide additional benefits for evaluation of MH by conventional colonoscopy in quiescent UC.