title: IMP3, a Promising Prognostic Marker in Clear Cell Renal Cell Carcinoma.
abstract: BACKGROUND
  Insulin-like growth factor II mRNA-binding protein 3 (IMP3) has been reported as a prognostic biomarker in various cancers. To validate IMP3 as a prognostic biomarker in renal cell carcinoma (RCC), we investigated the expression of IMP3, p53, and Ki-67, and their associations with clinicopathologic outcomes.
  
  
  METHODS
  We studied 148 clear cell RCCs (CCRCCs) from patients who underwent radical nephrectomy. The expression levels of IMP3, p53, and Ki-67 were assessed by immunohistochemical staining and the clinical and pathologic parameters were retrospectively reviewed.
  
  
  RESULTS
  Twenty-nine percent of CCRCCs expressed IMP3. Forty-one percent of IMP3-immunopositive tumors developed metastases, while only 11.4% of IMP3-negative tumors developed metastases (p<.001). A Kaplan-Meier curve showed that patients with IMP3-immunopositive tumors had lower metastasis-free survival and cancer-specific survival than did those with IMP3-immunonegative tumors (p<.001 and p<.001, respectively). Expression of high Ki-67 proliferation index was also associated with a higher metastatic rate. In the multivariate Cox regression analysis, pT stage and IMP3-positivity were independently associated with disease-specific survival.
  
  
  CONCLUSIONS
  IMP3 is an independent prognostic biomarker for patients with CCRCC to predict metastasis and poor outcome.
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Misun
authors.initials: M
authors.lastname: Choe
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Yuna
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Pathology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Sang Sook
authors.initials: SS
authors.lastname: Lee
keywords: Carcinoma, renal cell; IMP3; Ki-67; Neoplasm metastasis; Tumor suppressor protein p53