Dysplasia 4/19/2017. How do I practice Chromoendoscopy for Surveillance of Colitis? SCENIC: Polypoid Dysplasia in UC. Background

Transcription

1 SCENIC: Polypoid in UC Definition How do I practice for Surveillance of Colitis? Themos Dassopoulos, M.D. Director, BSW Center for IBD Themistocles.Dassopoulos@BSWHealth.org Tel: Cell: Polypoid Pedunculated Sessile Lesion protruding from the mucosa into the lumen 2.5 mm Lesion attached to the mucosa by a stalk No stalk; entire base is contiguous with the mucosa Background SCENIC: Nonpolypoid in UC Ulcerative colitis (UC) carries an increased risk of colorectal cancer (CRC) The precursor of CRC in UC is dysplasia Inflamed, non-neoplastic epithelium Indefinite Low-grade High-grade is described by both its histologic and endoscopic features CRC Nonpolypoid Definition Lesion without protrusion or protruding < 2.5 mm Superficial elevated Lesion with protrusion 2.5 mm Flat Depressed Flat lesion Lesion with at least a portion depressed below the mucosa level Discovered on random biopsies *Avoid the term flat Variable endoscopic appearance DALM Non-polypoid dysplasia Adenoma-like DALM Adenoma-like mass Adenoma-like polyp Polypoid dysplasia The terms: SCENIC: Nonpolypoid in UC -associated lesion or mass (DALM) Adenoma-like polyp/lesion Non-adenoma-like polyp/lesion are no longer in usage 1

2 Morphology in UC Polypoid Pedunculated or sessile Nonpolypoid Superficial elevated, flat, or depressed Borders Distinct Distinct or indistinct impact without chromoendoscopy Endoscopic resectability Variable Variable Better visualized by chromoendoscopy Why Perform? Randomized clinical trials have found CE superior to white-light endoscopy (WLE) using standard definition scopes in detecting dysplasia Meta-analysis supports the use of CE CE has been endorsed by SCENIC, ASGE, ECCO and British Society of Gastroenterology Not endorsed by the AGA (CE) Kiesslich, Gastroenterology 2003 Application of dyes to enhance the mucosal surface and the margins of lesions Two varieties of stains Contrast (indigo carmine 0.2%-0.9%) Absorptive (methylene blue 0.1%) MB 0.1% (n=84) WLE (n=81) Patients with dysplasia 13 6 NS P LGD/HGD 24/8 8/2 Flat Invasive cancers 3 1 NS Kiesslich. Gastro. 2003; Ko. Clin Endosc Advantages of Kiesslich, Gastroenterology 2003 Detects depressed, flat or superficial elevated lesions not readily seen on white-light endoscopy Delineates lesion margins Allows assessment of the pit pattern No significant learning curve* High prevalence of cancer Unique patient population CE compared with WLE using standard definition scopes No information on 1) characteristics of dysplastic lesions and 2) clinical significance *Carballal. Gut

3 Rutter, Gut 2004 SCENIC Guidelines When performing surveillance with white-light colonoscopy, high definition is recommended rather than standard definition (strong recommendation; low quality evidence) When performing surveillance with standard-definition colonoscopy, chromoendoscopy is recommended rather than white-light colonoscopy (strong recommendation; moderate quality evidence) When performing surveillance with high-definition colonoscopy, chromoendoscopy is suggested rather than white-light colonoscopy (conditional recommendation; low quality evidence) SCENIC international consensus. Gastroenterology Meta-analysis (n=1277) Arguments Against Some groups have not found CE superior to WLE Mooiweer (2015): CE 11% vs. WLE 10% No comparisons of HD WLE and CE Natural history of CE-detected lesions unknown No synchronous cancers were identified in patients undergoing colectomy for CE-detected dysplasia (Marion 2008 and 2016) Practical Challenges Pooled incremental yield on patient basis 7% (95% CI ) Number needed to treat: 14 Subramanian, Aliment Pharmacol Ther The yield of random biopsies is not insignificant Mooiweer (2015): 1% of procedures Patients with dysplasia (n=1277) Meta-analysis Pooled Incremental yield 95% Confidence Interval 7% (n=1277) 44% Flat dysplasia (n=1118) 27% Mean procedure time +11 minutes Advantages Detects subtle lesions Higher yield per biopsy No significant learning curve* Limitations Avoid in active disease or multiple pseudopolyps Need excellent bowel preparation Time-consuming No reimbursement by insurance Not adopted in practice Natural history of dysplasia according to morphology unknown WLE with random biopsies Advantages Not all dysplasia is visible Bowel prep need not be perfect No published studies comparing CE with WLE using high definition scopes Limitations Very low yield even with recommended no. of biopsies Still requires meticulous exam Natural history of invisible dysplasia in current era unknown Subramanian, Aliment Pharmacol Ther *Carballal. Gut. 2016; Wang. Am J Gastroenterol

4 Newest Systematic Review and Meta-analysis vs. SD WLE My Confession I do not perform CE in all patients Even when performing CE, I still obtain random biopsies Iannone. Clin Gastroenterol Hepatol. In Press. Newest Systematic Review and Meta-analysis vs. HD WLE When Do I Use CE? High-risk patients Prior visible or invisible dysplasia Chronically diseased colon (tubular, foreshortened) Extensive colitis of long duration Primary sclerosing cholangitis CE identified more patients with dysplasia only when compared with SD WLE Not in low-risk patients Normal mucosa Iannone. Clin Gastroenterol Hepatol. In Press. Management of dysplasia before chromoendoscopy Technique Need excellent prep (liquids for 2 days) Wash mucosa Spray dye Examine carefully Real life experience Easy to learn Messy Time-consuming (schedule extra time) LGD Multifocal or repetitive Unifocal HGD Unresectable Total Proctocolectomy OR resectable Surveillance 4

5 Management of dysplasia in chromoendoscopy era LGD HGD Unresectable resectable Total Proctocolectomy Surveillance SCENIC: For patients with endoscopically invisible dysplasia (confirmed by a GI pathologist) referral is suggested to endoscopist with expertise in IBD surveillance using chromoendoscopy with high-definition colonoscopy (conditional recommendation; very-low-quality evidence) Summary Should chromoendoscopy be the standard for surveillance of colitis? YES Challenges to implementation Time-consuming Clinician inertia 5