title: Immunohistochemical study of p53 overexpression in radiation-induced colon cancers.
abstract: The expressions of p53 and proliferating cell nuclear antigen (PCNA) were studied immunohistochemically from paraffin sections of 7 cases (9 lesions) of radiation-induced colon cancer and 42 cases of spontaneous colon cancer. Age distribution of radiation-induced and spontaneous colon cancer were 68.1 years (range, 56 to 77 years) and 67.4 years (range, 31 to 85 years), respectively. Among the radiation-induced colon cancers, there were 3 lesions of mucinous carcinoma (33%), a much higher than found for spontaneous mucinous cancer. Immunohistochemically, p53 protein expression was detected in 7/9 (78%) of radiation-induced cancers and in 23/42 (55%) of spontaneous colon cancers. chi 2 analysis found no significant differences between radiation-induced and spontaneous colon cancers in age distribution or p53-positive staining for frequency, histopathology, or Dukes' classification. In radiation colitis around the cancers including aberrant crypts, spotted p53 staining and abnormal and scattered PCNA-positive staining were observed. In histologically normal cells, p53 staining was almost absent and PCNA-positive staining was regularly observed in the lower half of the crypt. In radiation colitis including aberrant glands, cellular proliferation increased and spotted p53 expression was observed. This study suggests that radiation colitis and aberrant glands might possess malignant potential and deeply associate with carcinogenesis of radiation-induced colon cancer.
authors.affiliation: Department of Radiology, Nagasaki University School of Medicine, Japan. d393036r@stcc.nagasaki-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Minami
authors.forename: S
authors.initials: S
authors.lastname: Matsuzaki
authors.forename: N
authors.initials: N
authors.lastname: Hayashi
authors.forename: A
authors.initials: A
authors.lastname: Mokarim
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: I
authors.initials: I
authors.lastname: Sekine
mesh_terms: D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D016158:Genes, p53; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000378:metabolism*; D016609:Neoplasms, Second Primary / Q000235:genetics / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53