title: Decreased expression of claudin-1 in rectal cancer: a factor for recurrence and poor prognosis.
abstract: OBJECTIVE
  To investigate the potential involvement of claudin-1 (CL-1) in the tumorigenesis of rectal cancer by analyzing the correlation between CL-1 expression, clinicopathological factors and prognosis.
  
  
  METHODS
  Rectal cancer tissue specimens from 306 patients that had undergone surgical treatment were evaluated using immunohistochemical analysis for expression of CL-1 and correlated with clinicopathological factors.
  
  
  RESULTS
  A reduced expression of CL-1 (less than 30% of tumor cells strongly, positively stained) correlated significantly with poor prognosis in stage II and III rectal cancer. Moreover, the expression levels of CL-1 correlated significantly with tumor differentiation and perineural invasion (p=0.037 and 0.009, respectively). However, no significant differences were detected between the expression levels of CL-1 and other clinicopathological factors.
  
  
  CONCLUSIONS
  Loss of claudin-1 expression is a strong predictor of disease recurrence and poor patient survival in stage II and III rectal cancer.
authors.affiliation: Department of Surgery, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan. kinugasa_tetsushi@med.kurume-u.ac.jp
authors.forename: Takefumi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Kinugasa
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Akagi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kawahara
authors.forename: Kansakar
authors.initials: K
authors.lastname: Romeo
authors.forename: Ichitarou
authors.initials: I
authors.lastname: Shiratsuchi
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ryu
authors.forename: Yukito
authors.initials: Y
authors.lastname: Gotanda
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shirouzu
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002454:Cell Differentiation; D002462:Cell Membrane / Q000737:chemistry; D062445:Claudin-1; D003593:Cytoplasm / Q000737:chemistry; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis / Q000502:physiology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis / Q000502:physiology*; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000737:chemistry / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D012008:Recurrence
chemical_list: D014408:Biomarkers, Tumor; C568108:CLDN1 protein, human; D002272:Carcinoembryonic Antigen; D062445:Claudin-1; D008565:Membrane Proteins; D009363:Neoplasm Proteins