P140 Biopsies taken from mucosa surrounding dysplastic lesions found during IBD surveillance show a low rate of dysplasia
J. Ten Hove*1, E. Mooiweer1, A. Van der Meulen2, E. Dekker3, J. Offerhaus1, C. Ponsioen3, B. Oldenburg1
1University Medical Centre Utrecht, Utrecht, Netherlands, 2Leiden University Medical Centre, Leiden, Netherlands, 3Amsterdam Medical Centre, Amsterdam, Netherlands
When dysplastic lesions are encountered during surveillance colonoscopy in patients with IBD, guidelines generally recommend taking additional biopsies from the surrounding mucosa (SM), to ensure that the margins are free of dysplasia. No previous studies have assessed the yield of these biopsies in clinical practice. Aim: to assess the dysplasia yield of biopsies taken adjacent to neoplastic lesions found during IBD surveillance and evaluate the clinical consequences.
Patients undergoing colonoscopic surveillance for ulcerative colitis (UC) or Crohn’s disease (CD) between 2000 and 2015 were identified in 3 tertiary referral centres. All neoplastic lesions detected in the observed period were retrospectively assessed for the presence of additional biopsies taken from normal-looking mucosa surrounding the lesion. Cases would be included for further analysis if biopsies were unequivocally traceable to a single dysplastic lesion. Lesions classified as indefinite for dysplasia, high-grade dysplasia, or carcinoma were excluded.
In total, 1 065 patients underwent colonoscopic surveillance for IBD in the study period. Amongst 194 patients with ≥ 1 visible dysplastic lesion, SM biopsies were taken from 1 or more dysplastic lesions in 69 patients (male 62.3%; UC 48%; CD 42%; IBD-U 10%). Mean age at the time of IBD diagnosis was 35 years, and mean age at the time of dysplasia diagnosis was 57 years. Further, 136 lesions were identified that had accompanying biopsies of the SM. The mean number of adjacent biopsies per lesion was 3.4 (range 1–7). The overall rate of dysplasia in SM biopsies was 5/136 (3.7%) per lesion and was 5/486 (1.0%) per SM biopsy bite. Positive cases were observed using both white-light endoscopy (n = 3) and chromoendoscopy (n = 2). In none of the cases was the SM dysplasia considered a direct indication for colectomy. None of the patients with one or more SM biopsies positive for dysplasia had progression to high-grade dysplasia (HGD) or CRC on post-resection surveillance.
The overall rate of dysplasia in SM biopsies is low and has limited clinical consequences. These findings suggest that the endoscopic ability to delineate the borders of dysplastic lesions is good in the setting of IBD surveillance. The lack of clinical consequences related to routinely taking SM biopsies for every dysplastic lesion casts doubt on the usefulness and cost-effectiveness of this practice.