Expression of CXCR4 and breast cancer prognosis: a systematic review and meta-analysis

Background: The chemokine receptor CXCR4 plays a significant role in biological processes, as well as in tumorigenesis and the progression of cancer, especially breast cancer. However, the clinical application of CXCR4 for breast cancer prognosis is still very limited. A meta-analysis based on published studies was performed with the aim of obtaining an accurate evaluation of the relationship between CXCR4 expression and the prognosis of breast cancer. Methods: A comprehensive search strategy was used to search relevant literature in PubMed, MEDLINE and the ISI Web of Science. The correlation between CXCR4 expression and clinicopathological features and breast cancer prognosis was analyzed. This meta-analysis was carried out using Review Manager 4.2. Result: Thirteen eligible studies consisting of 3865 participants were included. We found that breast cancers with CXCR4 expression were associated with lymph node status (pooled RR = 1.20, 95% CI: 1.01-1.43, P<0.001) and distant metastasis (pooled RR = 1.52, 95% CI: 1.17-1.98, P = 0.125). CXCR4 overexpression was significantly associated with disease free survival (DFS) (RR = 0.77, 95% CI = 0.70-0.86, P = 0.554) and overall survival (OS) (RR = 0.70, 95% CI = 0.59-0.83, P = 0.329). However, there was no significant association between CXCR4 expression and some clinical parameters of breast cancer, such as tumor category, ER status, PR status, or c-erbB-2 status. Conclusion: Our meta-analysis showed that CXCR4 is an efficient prognostic factor for breast cancer. Overexpression of CXCR4 was significantly associated with lymph node status and distant metastasis and indicated poor overall and disease free survival.