title: Negative hMSH2 protein expression in pancreatic carcinoma may predict a better prognosis of patients.
abstract: The prognostic values of immunohistochemical staining for hMSH2 and hMLH1 in patients with pancreatic carcinomas were investigated. Fifty-five patients with histologically proven pancreatic carcinomas were studied. Immunohistochemical staining for hMSH2 and hMLH1 was performed by avidin-biotin-peroxidase complex method with a catalyzed signal amplification system. Tumor cells that exhibited an absence of nuclear staining in the presence of non-neoplastic cells with nuclear staining were considered to have an abnormal pattern. Four tumors (7.3%) demonstrated abnormal hMS2-negative staining. One tumor (1.8%) had abnormal hMLH1-negative staining and this tumor showed negative hMSH2 staining. No particular clinicopathologic factor such as tumor location, histology, T-factor, N-factor and TNM-stage were observed in patients with negative hMSH2 staining tumors. Median survival time (MST) of patients with hMSH2-negative tumors was comparatively longer than that of patients with hMSH2-positive tumors, however, there was no significant difference between MSTs of the two groups (56 months vs. 14 months; p=0.16). We concluded that negative hMSH2 immunohistochemical staining in the pancreatic carcinomas may demonstrate certain patients, but not all, who had microsatellite instability-positive tumors. The patients with hMSH2-negative tumors may have better prognoses than those with hMSH2-positive tumors. To clarify these findings, further large number of pancreatic carcinomas must be investigated.
authors.affiliation: Department of Surgical Oncology (First Department of Surgery), Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan. bunzo@med.osaka-cu.ac.jp
authors.forename: Bunzo
authors.initials: B
authors.lastname: Nakata
authors.forename: Yan Qing
authors.initials: YQ
authors.lastname: Wang
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yashiro
authors.forename: Masaichi
authors.initials: M
authors.lastname: Ohira
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Hiroji
authors.initials: H
authors.lastname: Nishino
authors.forename: Shuichi
authors.initials: S
authors.lastname: Seki
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002352:Carrier Proteins; D002454:Cell Differentiation; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D015996:Survival Rate
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C501486:MLH1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein