title: CA9 as a biomarker in preoperative biopsy of small solid renal masses for diagnosis of clear cell renal cell carcinoma.
abstract: OBJECTIVE
  The purpose of our study was to test the utility of CA9 expression in preoperative biopsy samples to identify the ccRCC.
  
  
  METHODS
  A total of 55 patients with a small solid renal mass (≤4 cm) entered into this study. The immunohistochemical staining (51 samples) and RT-PCR (33 samples) were performed to detect CA9 expression.
  
  
  RESULTS
  For immunohistochemistry detection, CA9 was positive in 31/34 of biopsy samples of ccRCCs. CA9 was also positive in five suspected diagnosis of ccRCC. For RT-PCR detection, CA9 was positive in 25/25 biopsy samples of ccRCCs. The diagnostic accuracy of CA9 expression for ccRCC was 100%. RT-PCR was performed in four biopsies where immunohistochemistry could not be performed because of limited tissue materials or necrosis. Two ccRCCs with a negative staining by immunohistochemistry were CA9 positive by RT-PCR.
  
  
  CONCLUSIONS
  CA9 may be potentially useful biomarker in help making a diagnosis of ccRCC in the biopsy of renal mass. RT-PCR might be a preferred method to immunohistochemistry for the detection of CA9 in renal biopsy samples.
authors: a Department of Urology , CHU de Saint-Etienne , Saint-Etienne , France.
authors: Guorong
authors: G
authors: Li
authors: c Clinical Genetics Laboratory , Yijishan Hospital of Wannan Medical College , Wuhu , China.
authors: Gang
authors: G
authors: Feng
authors: d Laboratory of Cancer Research , Zhejiang Cancer Research Institute, Zhejiang Province Cancer Hospital , Hangzhou , China.
authors: An
authors: A
authors: Zhao
authors: e Laboratory of Pathology , CHU Saint-Etienne , Saint-Etienne , France.
authors: Michel
authors: M
authors: Péoc'h
authors: b Inserm U1059 , F-42055 , Saint-Etienne , France.|f Laboratory of Cytopathology , CHU Saint-Etienne , Saint-Etienne , France.
authors: Michèle
authors: M
authors: Cottier
authors: a Department of Urology , CHU de Saint-Etienne , Saint-Etienne , France.
authors: Nicolas
authors: N
authors: Mottet
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D000071231:Carbonic Anhydrase IX / Q000032:analysis*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis*; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000175:diagnosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D000071231:Carbonic Anhydrase IX
keywords: CA9; RT-PCR; Renal tumours; biopsy; immunohistochemistry