title: Distinct expression profile of key molecules in crawling-type early gastric carcinoma.
abstract: BACKGROUND
  Gastric "crawling-type" adenocarcinoma (CRA) is a tumor histologically characterized by irregularly fused glands with low-grade cellular atypia that tends to spread laterally in the mucosa. To date, the expression characteristics of the key molecules involved in CRA, including receptor tyrosine kinases (RTKs), mismatch repair (MMR) proteins, phosphatase and tensin homolog (PTEN), as well as the Epstein-Barr virus (EBV) status, have yet to be uncovered.
  
  
  METHODS
  We constructed tissue microarrays of 94 CRAs, 72 conventional-type differentiated adenocarcinomas (CDAs), and 71 intramucosal poorly cohesive adenocarcinomas (PCAs) from early gastric cancers to evaluate and compare the pathological and expression profiles of potential key molecules for molecular classification (EBV; four MMR proteins-MLH1, MSH2, PMS2, and MSH6; three RTKs-HER2, MET, and EGFR; PTEN; and p53).
  
  
  RESULTS
  None of the CRAs showed MMR deficiency (0.0 % vs. 5.6 %, CRA vs. CDA, p = 0.036), HER2 overexpression (0.0 % vs. 12.5 %, p = 0.001), or loss of PTEN expression (0.0 % vs. 9.7 %, p = 0.003). Moreover, MET overexpression (4.4 % vs. 19.4 %, p = 0.004), and a mutant p53 pattern (12.4 % vs. 62.5 %, p < 0.001) were significantly less common in CRAs than in CDAs. However, clinicopathological features and all the profile of the molecules of CRAs were close to those of the PCA group.
  
  
  CONCLUSIONS
  CRA demonstrated unique clinicopathological characteristics and showed a distinct expression profile of key molecules, which was close to that of a null phenotype. These results support the classification of CRA as a distinct subgroup of gastric adenocarcinoma.
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Woo
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
authors.forename: Yoon Sung
authors.initials: YS
authors.lastname: Bae
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jie-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang Kil
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Cheong
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Noh
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea. kimhyunki@yuhs.ac.
authors.forename: Hyunki
authors.identifier: http://orcid.org/0000-0003-2292-5584
authors.initials: H
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000473:pathology*; D059467:Transcriptome
chemical_list: D014408:Biomarkers, Tumor
keywords: Crawling-type adenocarcinoma; Gastric cancer; Protein expression profile