Low risk of new dysplastic lesions in an inflammatory bowel disease population study with dye-chromoendoscopy

Background: We are yet to determine the rates of new dysplastic lesions or cancer progression after first dye chromoendoscopy in the era of high-definition endoscopy Aim and Methods: We developed a multicenter, population-based, retrospective cohort from 7 hospitals in Spain. Patients with inflammatory bowel disease and fully resected (R0) dysplastic colon lesions in surveillance with high-definition dye-based chromoendoscopy were sequentially enrolled between February 2011 and June 2017, with a minimum endoscopic follow-up of 36 months. The aim was to assess the incidence of developing more advanced metachronous neoplasia by analyzing possible associated risk factors. Results: The study sample included 99 patients and 148 index lesions (145 low-grade dysplasia lesions [LGD] and 3 high-grade dysplasia lesions [HGD]) with a mean follow-up of 48.76 months (IQR: 36.34–67.15). The overall incidence for new dysplastic lesions was 0.23 per 100 patient–year, 1.15 per 100 patients at 5 years and 2.29 per 100 patients at 10 years. A history of dysplasia was associated with a higher risk of developing any grade of dysplasia during follow-up (p=0.025), whereas left colon lesions were associated with a lower risk (p=0.043). The incidence of more advanced lesions at 1 year and 10 years was 1% and 14% respectively, with lesion size > 1 cm being a risk factor (p=0.041). One of the eight patients (13%) with HGD lesions developed CRC during follow-up. Conclusions: The risk of dysplasia progressing to advanced neoplasia and, specifically, the risk of new neoplastic lesions after endoscopic resection of colitis-associated dysplasia are both very low