title: Meta-Analysis of the Relationship between CXCR4 Expression and Metastasis in Prostate Cancer.
abstract: OBJECTIVE
  Experimental studies have suggested that the stromal-derived factor-1 (SDF-1)/CXCR4 axis is associated with tumor aggressiveness and metastasis in several malignancies. We performed a meta-analysis to elucidate the relationship between CXCR4 expression and the clinicopathological features of prostate cancer.
  
  
  METHODS
  Data were collected from studies comparing Gleason score, T stage, and the presence of metastasis with CXCR4 levels in human prostate cancer samples. The studies were pooled, and the odds ratio (OR) of CXCR4 expression for clinical and pathological variables was calculated.
  
  
  RESULTS
  Five articles were eligible for the current meta-analysis. We found no relationship between CXCR4 expression and Gleason score (<7 vs. ≥7). The forest plot using the fixed-effects model indicated an OR of 1.585 (95% confidence interval [CI]: 0.793~3.171; p=0.193). Further, CXCR4 expression was not associated with the T stage (<T3 vs. ≥T3), and the relevant meta-analysis showed OR=1.803 (95% CI: 0.756~4.297, p=0.183). However, increased CXCR4 expression was strongly associated with metastatic disease with a fixed-effects pooled OR of 7.459 (95% CI: 2.665~20.878, p<0.001).
  
  
  CONCLUSIONS
  Our meta-analysis showed that the higher CXCR4 protein expression in prostate cancer specimens is significantly associated with the presence of metastatic disease. This supports previous experimental data supporting the role played by the SDF-1/CXCR4 axis in metastasis.
authors.affiliation: Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Joo Yong
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Urology, Yangpyeong Health Center, Yangpyeong, Korea.
authors.forename: Dong Hyuk
authors.initials: DH
authors.lastname: Kang
authors.affiliation: Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Doo Yong
authors.initials: DY
authors.lastname: Chung
authors.affiliation: Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jong Kyou
authors.initials: JK
authors.lastname: Kwon
authors.affiliation: Division of Epidemic Intelligence Service, Korea Centers for Disease Control and Prevention, Osong, Korea.
authors.forename: Hyungmin
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Pathology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Nam Hoon
authors.initials: NH
authors.lastname: Cho
authors.affiliation: Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Deuk
authors.initials: YD
authors.lastname: Choi
authors.affiliation: Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Urology, Gangnam Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kang Su
authors.initials: KS
authors.lastname: Cho
keywords: Meta-analysis; Neoplasm metastasis; Prostatic neoplasms; Receptors, CXCR4