title: A gene signature of primary tumor identifies metastasized seminoma.
abstract: BACKGROUND
  The aim of this study was the prediction of metastatic status in seminoma based on examination of the primary tumor.
  
  
  METHODS
  Total RNA was isolated from metastasized seminoma (n = 10, T1N1-2M0), non-metastasized seminoma (n = 21, T1-3N0M0), and corresponding normal tissues. Pooled RNA from 10 biopsies of each tissue type was hybridized on whole genome microarrays for screening purposes. Ninety-two selected gene candidates were quantitatively examined using real-time quantitative polymerase chain reaction (RTQ-PCR).
  
  
  RESULTS
  Agreement in gene expression was 88% between the whole genome microarrays and RTQ-PCR. Metastasized seminoma showed 1,912 up-regulated and 2,179 down-regulated genes with ≥ 2-fold differences in gene expression compared non-metastasized seminoma. RTQ-PCR of selected genes showed that mean gene expression values were significantly reduced in metastasized compared with non-metastasized seminoma. The presence of metastases could be predicted based on an 85-gene expression signature by using logistic regression. Sensitivity and accuracy of the 10-fold cross-validation model were 77.8% and 84.2%, respectively.
  
  
  CONCLUSIONS
  A logistic regression model using an 85 gene expression signature allowed identification of metastasized seminoma from the primary tumor with a sensitivity of 77.8%.
authors: Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany.
authors: Matthias
authors: M
authors: Port
authors: Yu
authors: Y
authors: Wang
authors: Hans Ulrich
authors: HU
authors: Schmelz
authors: Tobias
authors: T
authors: Pottek
authors: Viktor
authors: V
authors: Meineke
authors: Christian
authors: C
authors: Ruf
authors: Michael
authors: M
authors: Abend
mesh_terms: D000328:Adult; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000235:genetics; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction; D018239:Seminoma / Q000235:genetics* / Q000473:pathology; D012680:Sensitivity and Specificity; D013736:Testicular Neoplasms / Q000235:genetics* / Q000473:pathology