title: The chemokine receptor CXCR4 as a novel independent prognostic marker for node-positive breast cancer patients.
abstract: BACKGROUND
  Node-positive breast cancer patients are a high-risk group. However, not all such patients will succumb to the disease. The molecular basis for this biologic heterogeneity is poorly understood. The chemokine receptor CXCR4 is a marker of metastatic disease. Its prognostic role in node-positive patients is unknown. We postulate that high CXCR4 overexpression in node-positive breast cancer specimens predicts a poor outcome.
  
  
  METHODS
  185 node-positive breast cancer patients were evaluated. All had standardized treatment and surveillance protocols. CXCR4 levels were detected with Western blots. Results were quantified against 1 µg of HeLa cells. CXCR4 expression was defined as high (≥ 7.5-fold) or low (<7.5-fold). Primary endpoints were cancer recurrence and death. Statistical analyses were Kaplan-Meier curves, log-rank test, and Cox proportional hazard model, with a P-value of ≤ 0.05 as significant.
  
  
  RESULTS
  The mean follow-up time was 54 months; 148 patients (80%) had low CXCR4 and 37 patients (20%) had high CXCR4 level. The 5-year overall survival (OS) for the low and high CXCR4 group was 69% and 57%, respectively (P=0.02). The 5-year disease-free survival (DFS) for the low and high CXCR4 group was 62% and 53%, respectively (P=0.08). On multivariate analysis, T stage (P=0.001) and grade (P=0.04) were independent predictors of DFS, while T stage (P=0.005), grade (P=0.024), and CXCR4 level (P=0.01) were independent predictors of OS.
  
  
  CONCLUSIONS
  High CXCR4 level in cancer specimens independently predicts a poor outcome for patients with node-positive breast cancer.
authors.affiliation: Department of Surgery and Division of Surgical Oncology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Parker
authors.forename: Roger H
authors.initials: RH
authors.lastname: Kim
authors.forename: Benjamin D L
authors.initials: BD
authors.lastname: Li
authors.forename: Quyen D
authors.initials: QD
authors.lastname: Chu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D019718:Receptors, CXCR4 / Q000032:analysis*
chemical_list: C527276:CXCR4 protein, human; D019718:Receptors, CXCR4