title: Sialosyl-Tn antigen is prevalent and precedes dysplasia in ulcerative colitis: a retrospective case-control study.
abstract: OBJECTIVE
  Expression of the carbohydrate-associated sialosyl-Tn (STn) antigen has been correlated with carcinogenesis in sporadic colon cancer. This retrospective study analyzed surveillance colonoscopy biopsy specimens to determine whether STn antigen could serve as a marker for neoplasia risk in patients with long-standing ulcerative colitis.
  
  
  METHODS
  Eleven patients who developed dysplasia or cancer and who had undergone at least three surveillance colonoscopies were matched with 11 controls who had not developed neoplasia. Sections from 969 available surveillance biopsy specimens were stained immunohistochemically with monoclonal antibody TKH2 and were interpreted blindly.
  
  
  RESULTS
  Compared with controls, patients expressed STn antigen more frequently in their biopsy specimens (44% patient biopsy specimens vs. 11% control biopsy specimens). Patients were also more likely to undergo colonoscopies with two or more colonic segments expressing STn antigen (73% vs. 22%), repeated STn antigen expression in two or more consecutive colonoscopies (91% vs. 27%), and STn antigen expression proximal to the hepatic flexure (64% vs. 0%). STn antigen appearance preceded the detection of neoplasia by 7 or fewer years, and its preferential expression in patients was not confounded by the degree of active inflammation.
  
  
  CONCLUSIONS
  Repeated STn antigen expression in nondysplastic colonic mucosa may presage the development of neoplasia in long-standing ulcerative colitis and may be a useful adjunct to dysplasia during colonoscopic surveillance.
authors.affiliation: Gastrointestinal Research Laboratory, Department of Mecicine, Mount Sinai School of Medicine, City University of New York, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Itzkowitz
authors.forename: E
authors.initials: E
authors.lastname: Young
authors.forename: D
authors.initials: D
authors.lastname: Dubois
authors.forename: N
authors.initials: N
authors.lastname: Harpaz
authors.forename: C
authors.initials: C
authors.lastname: Bodian
authors.forename: A
authors.initials: A
authors.lastname: Chen
authors.forename: D B
authors.initials: DB
authors.lastname: Sachar
mesh_terms: D000328:Adult; D000368:Aged; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism*; D001706:Biopsy; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000473:pathology; D003106:Colon / Q000276:immunology* / Q000473:pathology; D003113:Colonoscopy; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011230:Precancerous Conditions / Q000276:immunology* / Q000473:pathology; D012189:Retrospective Studies
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; C055491:sialosyl-Tn antigen