Prognostic and clinicopathological value of CXCL12/SDF1 expression in breast cancer: A meta-analysis

Background: Several studies have demonstrated that stromal cell derived factor-1 (SDF1, also known as CXCL12) expression is a biomarker for breast cancer treatment; however, its significance of prognosis is inconsistent. This study uses a meta-analysis to explore the prognostic value of CXCL12/SDF1 expression in breast cancer. Materials and methods: PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception to November 25, 2017. Studies investigating the correlation between CXCL12/SDF1 expression and survival in breast carcinoma were included. The pooled hazard ratio (HR) and 95% confidence interval (95% CI) was used to assess the prognostic value of CXCL12/SDF1 in breast cancer. The pooled odds radio (OR) and 95% CI was applied to evaluate the relationship between CXCL12/SDF1 expression and the clinical characteristics of breast cancer. Results: Eight eligible studies involving 2205 patients were identified. Higher CXCL12/SDF1 protein expression was associated with better disease-free survival (DFS) (HR, 0.76; 95% CI, 0.68-0.86; P < .0001) and overall survival (OS) (HR, 0.66; 95% CI, 0.49-0.87; P = .004) in breast cancer. Furthermore, higher CXCL12/SDF1 protein expression was associated with positive ER status (OR, 1.92; 95% CI, 1.08-3.45; P = .03), negative HER2 status (OR, 2.64; 95% CI, 1.06-6.59; P = .04), and small tumor size (OR, 2.49; 95% CI, 1.47-4.22; P = .0007) in breast cancer, respectively. However, there were no significant associations between the CXCL12/SDF1 mRNA expression and other prognostic parameters, such as TNM stage, age, PR status, lymph node, and nuclear grade (P > .05 for all). Conclusions: This present meta-analysis suggests that CXCL12/SDF1 protein expression is a good prognostic biomarker in breast cancer. In addition, the over-expression of CXCL12/SDF1 protein was associated with positive ER status, negative HER2 status and small tumor size.