title: Overexpression of p53 protein and histologic grades of dysplasia in colorectal adenomas.
abstract: OBJECTIVE
  To clarify the relation between tumor-suppressor gene p53 expression and histologic grades of dysplasia in colorectal adenomas, we performed immunohistochemical analysis in a series of 59 colorectal polyps and 40 advanced carcinomas.
  
  
  METHODS
  Adenomatous polyps were stained by hematoxylin and eosin and classified into mild, moderate, and severe dysplasia (intramucosal carcinoma), according to the World Health Organization's classification.
  
  
  RESULTS
  p53 was positive in 7.1 percent (2/28) of mild, 29.4 percent (5/17) of moderate, and 62.5 percent (5/8) of severe dysplasia. In submucosal and advanced carcinomas, positivity rates were 75 percent (3/4) and 47.5 percent (19/40), respectively. Different staining patterns were found, according to grades of dysplasia. In the adenomas with mild or moderate dysplasia, a few focal crypts showed localized p53-positive staining. Adenomas with severe dysplasia had two different staining types. One was a focal staining type as shown in mild or moderate dysplasia; the other was a diffuse staining type, in which glands with mild or moderate dysplasia, surrounding severe dysplasia area, were also stained. Submucosal and advanced carcinomas showed a strong positive staining in cancer cells only.
  
  
  CONCLUSIONS
  Overexpression of p53 protein in adenomas with mild or moderate dysplasia and existence of two types of expression in adenomas with severe dysplasia were observed. These facts suggested the possible existence of different pathways in the adenoma to carcinoma progression.
authors.affiliation: Department of Surgery, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sameshima
authors.forename: Y
authors.initials: Y
authors.lastname: Kubota
authors.forename: T
authors.initials: T
authors.lastname: Sawada
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Kuroda
authors.forename: N
authors.initials: N
authors.lastname: Tsuno
authors.forename: Y
authors.initials: Y
authors.lastname: Higuchi
authors.forename: M
authors.initials: M
authors.lastname: Shinozaki
authors.forename: K
authors.initials: K
authors.lastname: Sunouchi
authors.forename: T
authors.initials: T
authors.lastname: Masaki
authors.forename: Y
authors.initials: Y
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Muto
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D003111:Colonic Polyps / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D016159:Tumor Suppressor Protein p53