Published in:
01-10-2009 | Breast Oncology
Overexpression of CXCR4 in Primary Tumor of Patients with HER-2 Negative Breast Cancer was Predictive of a Poor Disease-Free Survival: A Validation Study
Published in: Annals of Surgical Oncology | Issue 10/2009
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Background
Although HER-2 negative tumors are thought to be less aggressive than their counterpart, there is a subset that behaves poorly. The molecular mechanism to account for this is unknown. The chemokine receptor CXCR4 is often upregulated in a wide array of cancers. Using a training dataset, we previously reported that high CXCR4 overexpression portends a poor outcome among patients with HER-2 negative breast tumors. This study aims to validate these findings, using our validation dataset.
Methods
There were 115 patients with stages I–III, HER-2 negative breast cancers who were prospectively accrued and analyzed. CXCR4 levels from primary tumors were detected using Western blots, and results were quantified against 1 μg of HeLa cells. CXCR4 expression was defined as low (<6.6 fold) or high (≥6.6 fold). Primary endpoint was cancer recurrence. Statistical analysis performed included Spearman correlation, Fisher exact test, Kaplan–Meier survival analysis, Cox proportional hazard ratio model, and log-rank test.
Results
There were 13 patients in the high (≥6.6 fold) and 102 patients in the low CXCR4 group (<6.6 fold). Overall survival (OS) and disease-free survival (DFS) for the cohort was 84 and 71%, respectively. The 5-year OS for the high CXCR4 group was 52% and for the low CXCR4 group was 86% (P = 0.08). The 5-year DFS for the high CXCR4 and low CXCR4 group was 38 and 74%, respectively (P = 0.01).
Conclusion
We validated that high CXCR4 overexpression in primary tumors of patients with HER-2 negative tumors portend a poor outcome. These findings should be confirmed with either a prospective clinical trial and/or an external validation study.