title: Detection of carbonic anhydrase-9 gene expression in peripheral blood cells predicts risk of disease recurrence in patients with renal cortical tumors.
abstract: OBJECTIVE
  To present extended follow-up on a cohort of patients with renal cortical tumors treated with partial or radical nephrectomy and preoperatively assess for carbonic anhydrase 9 tumor marker expression in the peripheral blood.
  
  
  METHODS
  All patients were originally enrolled in an institutional review board-approved study assessing the role of a reverse-transcriptase polymerase chain reaction peripheral blood assay designed to detect the tumor-specific gene carbonic anhydrase-9 (CA9). A total of 41 patients with renal cortical tumors confined to the kidney were enrolled at a single institution and assessed preoperatively with peripheral blood test for CA9 expression before undergoing partial or radical nephrectomy. A Kaplan-Meier estimated survival analysis and log-rank test were performed to determine whether detection of peripheral blood cells expressing the CA9 gene influences disease-free and disease-specific survival.
  
  
  RESULTS
  The median follow-up was 4.3 years. The median age was 71 years. Of the 41 patients, 26 were men and 15 were women. The estimated 5-year disease-free survival for patients with detectible expression of the CA9 gene in the peripheral blood was 39.5% compared with 88.1% for patients without detection of the CA9 gene (P = 0.048). On bivariate analysis, disease-free survival correlated with histologic type, tumor diameter, and tumor grade.
  
  
  CONCLUSIONS
  The expression of the tumor-specific marker CA9 in the peripheral blood is associated with decreased disease-free survival in patients with renal cortical tumors. This is the first study reporting on the prognostic value of this peripheral blood-based tumor marker for kidney tumors.
authors.affiliation: Squier Urological Clinic, Columbia University Medical Center, New York, New York 10032, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Gilbert
authors.forename: Jared M
authors.initials: JM
authors.lastname: Whitson
authors.forename: Mahesh
authors.initials: M
authors.lastname: Mansukhani
authors.forename: Ralph
authors.initials: R
authors.lastname: Buttyan
authors.forename: Mitchell C
authors.initials: MC
authors.lastname: Benson
authors.forename: Carl A
authors.initials: CA
authors.lastname: Olsson
authors.forename: Ihor S
authors.initials: IS
authors.lastname: Sawczuk
authors.forename: James M
authors.initials: JM
authors.lastname: McKiernan
mesh_terms: D018249:Adenoma, Oxyphilic / Q000097:blood / Q000235:genetics / Q000601:surgery; D000368:Aged; D018207:Angiomyolipoma / Q000097:blood / Q000235:genetics / Q000601:surgery; D014408:Biomarkers, Tumor / Q000097:blood*; D001773:Blood Cells / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000097:blood*; D002292:Carcinoma, Renal Cell / Q000097:blood / Q000235:genetics* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D015870:Gene Expression; D006801:Humans; D007680:Kidney Neoplasms / Q000097:blood / Q000235:genetics* / Q000601:surgery; D008297:Male; D009392:Nephrectomy; D011237:Predictive Value of Tests; D012008:Recurrence; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D002256:Carbonic Anhydrases