title: Association of CD44 isoform immunohistochemical expression with myometrial and vascular invasion in endometrioid endometrial carcinoma.
abstract: OBJECTIVE
  Appropriate clinical management of cases of FIGO Grade I and II endometrial carcinoma relies heavily on the determination of myometrial invasion (MI). There are no reports addressing expression of the cell adhesion molecule CD44 in the subset of Grade I and II endometrioid carcinoma (EC) as it relates to prognosis, including MI.
  
  
  METHODS
  Immunohistochemical staining for CD44s and CD44v6 was evaluated in 40 hysterectomy specimens with Grade I and II EC, including 11 noninvasive ECs, 14 with MI <50% of myometrial thickness, and 15 with deep invasion (MI >50%). Staining characteristics according to the presence of MI and vascular space invasion (VSI) were evaluated. Strong membranous staining of >10% of tumor cells was interpreted as positive.
  
  
  RESULTS
  CD44v6 staining was positive in 20% (8/40) of cases, including 45% (5/11) of EC without MI but only 10% (3/29) with MI (P = 0.025). CD44v6 staining was not present in deeply invasive tumors (0/15), while it was present in 8/25 superficially or noninvasive tumors (P = 0.016). Sensitivity and specificity were 25 and 100%, respectively, using CD44v6 in evaluating deep myometrial invasion. CD44s showed a trend toward positive staining when comparing noninvasive versus invasive tumors and noninvasive/superficially invasive versus deeply invasive tumors (P = 0.08 and 0.12, respectively). CD44s or CD44v6 staining was highly specific for absence of VSI, although statistical comparison did not reach significance.
  
  
  CONCLUSIONS
  Deeply invasive EC was associated with a consistent lack of CD44v6 expression. This may have potential clinical utility if this finding is demonstrated in further study of prehysterectomy sampling specimens containing EC.
authors.affiliation: Department of Pathology, Third Medical Group, Elmendorf AFB, Alaska 99506, USA.
authors.forename: Gary N
authors.initials: GN
authors.lastname: Stokes
authors.forename: Jack B
authors.initials: JB
authors.lastname: Shelton
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Zahn
authors.forename: Brian S
authors.initials: BS
authors.lastname: Kendall
mesh_terms: D018269:Carcinoma, Endometrioid / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D016889:Endometrial Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006023:Glycoproteins / Q000096:biosynthesis*; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D007150:Immunohistochemistry; D009215:Myometrium / Q000473:pathology*; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000378:metabolism; D020033:Protein Isoforms; D012995:Solubility
chemical_list: C112697:CD44v6 antigen; D006023:Glycoproteins; D018960:Hyaluronan Receptors; D020033:Protein Isoforms