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Colorectal Adenomas Santhat Nivatvongs MD Mayo Clinic Rochester Minnesota U. S.A.

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Presentation on theme: "Colorectal Adenomas Santhat Nivatvongs MD Mayo Clinic Rochester Minnesota U. S.A."— Presentation transcript:

1 Colorectal Adenomas Santhat Nivatvongs MD Mayo Clinic Rochester Minnesota U. S.A.

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3 ADENOMATOUS POLYPS OF COLON AND RECTUM Incidence Risk factors of an adenoma Natural history of an adenoma Serrated adenoma Colonoscopic polypectomy

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5 AUTOPSY SURVEY 658 Adenomas Distribution (%) Rectum 7 Other Findings Sigmoid 17 Ave size 0.6 cm Descending 9 Mean # 2.6 Transverse 28 increase # with age Ascending 26 No increase in size with age Cecum invasive Ca ( 1.7 % ) Rickert et al Cancer 1979;43:1847

6 COLONOSCOPIC INITIAL EXAM % Adenoma 85 Hyperplastic 15 Total 100 National Polyp Study Gastroent 1990; 98:371

7 Size of Colorectal Adenoma Initial Colonoscopy Size ( cm ) % < > Total 100 National Polyp Study Gastroent 1990; 98:371

8 Colorectal Adenoma Independent Risk Factors For High Grade Dysplasia Size Extent of Villous Increasing age National Polyp study Gastroent 1990;98:371

9 Size of Adenoma And Invasive Ca Size (cm) Invasive Ca (%) < > Nusko G et al. Endoscopy 1997; 20:626

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13 Colorectal Adenoma Advanced Adenoma Adenoma > 1 cm Villous component

14 The Adenoma -Carcinoma Sequence in Cancer of the Colon Raymond J. Jackman, M.D. and Charles W. Mayo, M.D., Rochester, Minnesota Surg Gynecol Obstet 1951;93:327

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17 Natural History of Small Adenomas Colorectal Adenomas < 5 mm 30 dimunitive adenomas (26 pt) Follow-up 2 yr Mean growth 0.6 mm / yr 2 / 30 reached 10 mm Bersentes K et al. Am J Gastroent 1997 ; 92 : 117

18 Natural History of Colorectal Adenomas 68 adenomas < 1 cm ( 58 pt ) Follow- up 3 yr 17 ( 25 % ) same size 27 ( 40 % ) grew ---- most rapid = 4mm in 3 yr 24 ( 35% ) shrunk Hofstad B et al. Gut 1996; 39 : 449

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20 Natural History of An Adenoma 1 cm or Larger N = 226 Mean Follow-up 5 yr (1-27 yr) % Disappear 5 No Growth 57 Growth 38 Otchy D et al. Am J Gastro 1996; 91:448

21 Natural History of An Adenoma Risk of >1cm adenoma Year Invasive Ca.(%) Stryker S et al. Gastroent 1987; 83:1009

22 Progression of Adenoma and Carcinoma From clean colon to adenoma 5 yr From clean colon to carcinoma 10 yr Winawer SW et al. Cancer 1991; 67:1143

23 Serrated Adenomatous Polyp Historical Perspectives Hyperplastic in adenomatous polyp Goldman H et al. Arch Pathol 1970; 89 : 349 Mixed hyperplastic adenomatous polyp Urbanski SJ et al. Am J Surg Path 1984; 8: 551 Serrated adenoma Longacre TA, Fenoglio – Preiser CM. Am J Surg Path 1990; 14: 524

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27 Molecular Study of Serrated Adenoma No APC mutation Kras mutation DNA microsatellite instability ( MSI – L ) Loss of Chromosome 1 P Mutation of TGF beta RI I Genetic = neoplastic polyp Jass JR DCR 2001; 44: 163

28 Risk Features of Serrated Adenoma Size > 1 cm Location in right colon Presence of high grade dysplasia Coincidental adenoma 1 st degree relatives with HGD 1 st degree relatives with CR Ca Jass JR DCR 2001 ; 44 : 163

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34 Colonoscopic Polypectomy Size of Polyps Size No. % – – – Unretrieved Total

35 Colonoscopic Polypectomy Complications in 2592 Polyps Problem No. Bleeding 20 ( resulted in 1 death ) Transmural burn 8 ( conservative treatment ) Perforation 2 ( conservative treatment ) Intra-abdominal abscess 1 ( CT drain ) Snare entrapment 1 ( surgery ) Ensnared bowel wall 1 ( surgery ) Total 33 ( 1.3% )

36 ADENOMATOUS POLYPS OF COLON AND RECTUM Incidence Risk factors of an adenoma Natural history of an adenoma Serrated adenoma Colonoscopic polypectomy


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