title: Expression of CA-IX is associated with advanced stage tumors and poor survival in oral squamous cell carcinoma patients.
abstract: BACKGROUND
  Carbonic anhydrases (CAs), a group of ubiquitously expressed metalloenzymes, are involved in numerous physiological and pathological processes, including tumorigenicity. Specifically, CA-IX has been primarily found in hypoxic tumor tissues.
  
  
  METHODS
  This is a retrospective study of tumors from the Tissue Bank of the Pathology Department of the University Hospital of Santiago de Compostela. We selected 50 oral squamous cell carcinomas (OSCCs) using Tissue Microarray (TMA) technology. The immunohistochemical study was performed to determine CA-IX expression. The resulting data were subject to statistical analysis and survival curves.
  
  
  RESULTS
  Of the 50 cases, 23 were detected in early stages (I and II) and 27 in advanced stages (III and IV). In the first year, almost 50% of patients in stages III-IV died, which contrasted with those patients in initial stages who registered a survival rate of 80% (P = 0.019). Regarding the expression of CA-IX, nine cases (18%) were negative, 18 cases (36%) were moderate, while 23 cases (46%) were intense. Tumors in stages I-II showed a positivity of 52.6%; however, in advanced stages, the percentage reached 95.5% (P = 0.002). Regarding CA-IX expression and survival, patients with tumors with strong staining had a lower average survival time (13.8 months) than patients with negative or weak-moderate staining (33.4 and 32.8 months, respectively), log-rank=6.1, P value=0.0484.
  
  
  CONCLUSIONS
  Early diagnosis of these tumors is essential to improve patient survival. CA-IX expression augments with increasing tumor stage, probably related with the degree of hypoxia; thus, its measurement can be used as a prognostic factor.
authors.affiliation: Department of Pathology, Forensic Sciences, University Hospital and School of Medicine of Santiago de Compostela, Servicio de Anatomia Patológica, Hospital Clinico de Santiago, Santiago de Compostela, Spain. perezsayans@gmail.com
authors.forename: Mario
authors.initials: M
authors.lastname: Pérez-Sayáns
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Suárez-Peñaranda
authors.forename: Gayoso-Diz
authors.initials: GD
authors.lastname: Pilar
authors.forename: Claudiu T
authors.initials: CT
authors.lastname: Supuran
authors.forename: Silvia
authors.initials: S
authors.lastname: Pastorekova
authors.forename: Francisco
authors.initials: F
authors.lastname: Barros-Angueira
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Gándara-Rey
authors.forename: Abel
authors.initials: A
authors.lastname: García-García
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000032:analysis*; D002278:Carcinoma in Situ / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002462:Cell Membrane / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis*; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology*; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D007527:Isoenzymes; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases