title: Prognostic significance of epithelial-mesenchymal transition of extracapsular spread tumors in lymph node metastases of head and neck cancer.
abstract: OBJECTIVE
  The extracapsular spread (ECS) of lymph node metastasis (LNM) reflects tumor aggressiveness and is associated with poor survival and risk of distant metastasis. In this study, we aimed to explore the prognostic significance of epithelial-mesenchymal transition (EMT) of ECS tumors in LNM of head and neck cancers.
  
  
  METHODS
  We collected LNM samples from head and neck cancer patients (follow-up >2 years) and made 20 ECS(-): ECS(+) pairs (1:2) of LNM (N = 60), matched by the primary sites and by T and N classifications. Immunostaining of cytokeratin, E-cadherin, vimentin, and CD31 were performed and quantified to determine the epithelial-mesenchymal transition percent (EMT%), defined as vimentin(+)/cytokeratin(+) area of ECS. Univariate and multivariable analyses of clinic-pathologic factors, including EMT% of ECS, were conducted to identify the significant prognosticators. In addition, the anatomical relationship between CD31 vessels and ECS tumors was analyzed.
  
  
  RESULTS
  Rather than the presence of ECS in LNM, higher EMT% (>50 %) of ECS strongly correlated with the worse overall and disease-free survival and had more frequent recurrence and distant dissemination in their clinical courses. ECS tumors intermingled closely with Ki-67(-) CD31(+) non-proliferating perinodal blood vessels. Particularly, vimentin(+) ECS areas exhibited a higher density of CD31(+) perinodal vessels than did vimentin(-) ECS.
  
  
  CONCLUSIONS
  High EMT scores of ECS tumors in LNM predict an unfavorable prognosis and systemic dissemination more accurately than the simple presence of ECS in LNM in head and neck cancer patients.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Won-Yong
authors.initials: WY
authors.lastname: Lee
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Shin
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Young-Hyeh
authors.initials: YH
authors.lastname: Ko
authors.forename: Sehoon
authors.initials: S
authors.lastname: Kim
authors.forename: Han-Sin
authors.initials: HS
authors.lastname: Jeong
mesh_terms: D015820:Cadherins / Q000032:analysis; D018572:Disease-Free Survival; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D006258:Head and Neck Neoplasms / Q000737:chemistry* / Q000473:pathology*; D006801:Humans; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D008198:Lymph Nodes / Q000098:blood supply*; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D015996:Survival Rate; D014746:Vimentin / Q000032:analysis
chemical_list: D015820:Cadherins; D019394:Ki-67 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014746:Vimentin; D007633:Keratins