title: Immunohistochemical studies of colorectal cancers that developed following pelvic irradiation.
abstract: Radiation therapy is believed to be a predisposing factor in the development of carcinoma. During the period from 1974 to 1997, we treated five colorectal cancers in four patients who had undergone pelvic irradiation for cervical cancer. Radiation-induced changes in the remaining bowel were recognized in all of these patients. Of the five tumors, two were histologically diagnosed as mucinous adenocarcinoma, demonstrating a higher distribution than usual: To clarify the characteristics of the tumors, we examined the frequency of mutation in K-ras and p53 genes, and the proliferating cell nuclear antigen (PCNA) proliferation activity. The K-ras and PCNA stains did not show any clear characteristics of radiation-induced colorectal cancers in comparison with ordinary colorectal cancers; however, it was of interest that strongly positive staining was observed in our mucinous adenocarcinomas, even though a low frequency of p53 gene mutation has been reported in ordinary mucinous adenocarcinomas.
authors.affiliation: First Department of Surgery, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama, Okayama 700-8558, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nakao
authors.forename: H
authors.initials: H
authors.lastname: Iwagaki
authors.forename: T
authors.initials: T
authors.lastname: Yoshino
authors.forename: A
authors.initials: A
authors.lastname: Jikuhara
authors.forename: T
authors.initials: T
authors.lastname: Kanagawa
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: N
authors.initials: N
authors.lastname: Matsubara
authors.forename: H
authors.initials: H
authors.lastname: Isozaki
authors.forename: N
authors.initials: N
authors.lastname: Takakura
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000737:chemistry / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000209:etiology / Q000473:pathology; D005260:Female; D016158:Genes, p53 / Q000235:genetics; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D009381:Neoplasms, Radiation-Induced / Q000737:chemistry* / Q000209:etiology / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D016283:Proto-Oncogene Proteins p21(ras) / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D002583:Uterine Cervical Neoplasms / Q000737:chemistry* / Q000209:etiology / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)