title: Molecular pathological subclassification of mucinous adenocarcinoma of the colorectum.
abstract: The purpose of the present report was to examine the possibility of molecular pathological subtyping of mucinous adenocarcinomas (MAC) of the colorectum. Thirty-five formalin-fixed and paraffin-embedded MAC specimens of the colorectum were analyzed. Genetic alterations of p53 gene and microsatellite instability (MSI) as well as immunohistochemical analysis of mucin subtypes (human gastric mucin (HGM), anti-mucin monoclonal antibody recognizing gastric gland mucous cells-1, MUC2, CD10) and expression levels of human mutL homolog 1 (hMLH1), p53 and Ki-67 were performed. According to MSI and p53 status, these tumors were subclassified into three groups: mutator-type tumors with a high frequency of MSI (20%), suppressor/p53-type tumors with p53 mutation, p53 overexpression or loss of heterozygosity of D17S250 (an adjacent locus to p53; 40%) and the unclassified tumors (40%). The suppressor/p53-type tumors had a significant association with distal colon location (P = 0.019), venous invasion (P = 0.002), extent of lymph node metastasis (P = 0.007) and higher tumor stage (P = 0.018). In contrast, mutator-type tumors had frequent expression of HGM (P = 0.005) and prominent lymphocytic infiltration at the advancing front of the tumor (P = 0.005). These results indicate that MAC of the colorectum could be subclassified according to molecular pathological background, reflecting distinct clinicopathological and phenotypic characteristics.
authors.affiliation: Division of Surgical Pathology, Department of Biomedical Informatics, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Shuho
authors.initials: S
authors.lastname: Semba
authors.forename: Ming
authors.initials: M
authors.lastname: Wu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokozaki
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002352:Carrier Proteins / Q000378:metabolism; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005752:Gastric Mucins / Q000378:metabolism; D042822:Genomic Instability; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008207:Lymphatic Metastasis; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology; D018895:Microsatellite Repeats; D000070957:MutL Protein Homolog 1; D009154:Mutation; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009687:Nuclear Proteins / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D014680:Veins / Q000473:pathology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D005752:Gastric Mucins; D019394:Ki-67 Antigen; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D016159:Tumor Suppressor Protein p53; D000070957:MutL Protein Homolog 1