title: Re-evaluation of phenotypic expression in undifferentiated-type early gastric adenocarcinomas using mucin core protein and CDX2.
abstract: BACKGROUND
  Undifferentiated-type early gastric adenocarcinomas are generally classified into two groups: pure undifferentiated-type adenocarcinomas, which naturally develop as undifferentiated-type without a glandular component; and mixed differentiated/undifferentiated-type adenocarcinomas, which are associated with some vestigial glandular component and presumably develop from differentiated-type adenocarcinoma. The differences in phenotypic expression between these two groups were examined using mucin core protein and CDX2.
  
  
  METHODS
  A total of 210 lesions of undifferentiated-type early gastric adenocarcinoma less than 25 mm in diameter were classified into four categories (gastric type, gastrointestinal type, intestinal type, and null type) based on their MUC5AC, MUC6, MUC2, and CDX2 immunoprofiles.
  
  
  RESULTS
  Gastric type was significantly (p < 0.01) decreased and gastrointestinal type was significantly (p < 0.01) increased both in pure undifferentiated-type adenocarcinomas and in mixed differentiated/undifferentiated-type adenocarcinomas when CDX2 was applied to mucin core protein. In the pure undifferentiated-type adenocarcinomas, gastric type decreased and gastrointestinal type increased as tumor size increased (p < 0.05). In contrast, in the mixed differentiated/undifferentiated-type adenocarcinomas, gastrointestinal type was most common even in small-sized (≤10 mm) carcinomas and was generally stable regardless of tumor size. In submucosal carcinomas, gastrointestinal type decreased and gastric type and intestinal type increased during carcinoma invasion from the intramucosal to submucosal parts (p < 0.05). The positivity rates for all phenotypic markers, especially gastric markers, tended to decrease during submucosal invasion.
  
  
  CONCLUSIONS
  CDX2 is a sensitive marker for assessing intestinal phenotypic expression, and it is likely that there are two different pathways of tumor progression in undifferentiated-type adenocarcinoma of the stomach, according to phenotypic expression.
authors: Division of Molecular and Diagnostic Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: Satoshi
authors: S
authors: Ikarashi
authors: Ken
authors: K
authors: Nishikura
authors: Yoichi
authors: Y
authors: Ajioka
authors: Yutaka
authors: Y
authors: Aoyagi
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism; D000071616:CDX2 Transcription Factor; D005260:Female; D018398:Homeodomain Proteins / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC / Q000032:analysis* / Q000378:metabolism; D055262:Mucin-2 / Q000032:analysis* / Q000378:metabolism; D055272:Mucin-6 / Q000032:analysis* / Q000378:metabolism; D011237:Predictive Value of Tests; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; C524734:MUC6 protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D055272:Mucin-6