title: Clinicopathologic relevance of claudin 5 expression in breast cancer.
abstract: OBJECTIVE
  Claudins are major adhesion molecules in tight junctions and are strongly expressed in various cancers. We thus investigated the expression of claudin 5, a member of the claudin family, in breast cancer.
  
  
  METHODS
  A total of 193 patients with breast cancer were identified based on their pathologic diagnosis. The expression of each claudin 5 was analyzed in the tumor by immunohistochemical staining. Parametric correlations were done between claudin 5 expression and the clinicopathologic findings.
  
  
  RESULTS
  Claudin 5 expression in patients with recurrent breast cancer was statistically significantly higher (P = .004). In addition, analysis of the correlation with other clinicopathologic factors showed statistically significant differences with respect to lymphatic invasion (P = .014), venous invasion (P = .048), estrogen receptor status (P = .002), and human epidermal growth factor 2 status (P = .007). Multivariate analysis revealed that claudin 5 expression was an independent predictive factor in the recurrence for relapse-free survival (RFS) (P = .020). Kaplan-Meier analysis showed that the RFS rate was significantly lower in the high claudin 5 expression group (P = .001).
  
  
  CONCLUSIONS
  Patients with breast cancer with high claudin 5 expression had a significantly lower RFS rate. Our findings suggest that claudin 5 may be useful as a new biomarker of a risk factor.
authors.affiliation: From the Departments of Surgical Oncology.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sugimoto
authors.affiliation: From the Departments of Surgical Oncology, nagahara.srg2@tmd.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nagahara
authors.affiliation: Human Pathology, and.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Bae
authors.affiliation: From the Departments of Surgical Oncology.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Translational Oncology, Graduate School of Medical & Dental Science, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: From the Departments of Surgical Oncology.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Sato
authors.affiliation: Translational Oncology, Graduate School of Medical & Dental Science, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uetake
authors.affiliation: Human Pathology, and.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Eishi
authors.affiliation: From the Departments of Surgical Oncology.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D062507:Claudin-5 / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012307:Risk Factors; D019108:Tight Junctions / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C107466:CLDN5 protein, human; D062507:Claudin-5
keywords: Breast cancer; Claudin 5; Tight junctions