Prognosis assessment of CD44 + /CD24 − in breast cancer patients: a systematic review and meta-analysis

Purpose This meta-analysis investigated the relationships between the CD44 + /CD24 − phenotype and tumor size, lymph node metastasis, distant metastasis, disease-free survival (DFS), and overall survival (OS) in 8036 postoperative breast cancer patients enrolled in 23 studies. Methods A literature search of PubMed, Medline, Cochrane, Embase, and PMC was conducted to identify eligible studies. The combined odds ratios (ORs) and 95% confidence intervals (95% CIs) were analyzed to evaluate the relationships between the CD44 + /CD24 − phenotype and the pathological and biological characteristics of breast cancer patients, and the combined hazard ratios (HRs) and 95% CIs were calculated to evaluate the relationships between CD44 + /CD24 − and DFS and OS of breast cancer patients using Stata12.0 software. Results The CD44 + /CD24 − phenotype were not related to the tumor size (tumor size > 2.0 vs ≤ 2.0 cm, combined OR = 0.98, 95% CI 0.68–1.34, p = 0.792) and did not promote lymph node metastasis (lymph node metastasis vs. no lymph node metastasis, OR = 0.92, 95% CI 0.67–1.27, p = 0.626) and distant metastasis (distant metastasis vs no distant metastasis, combined OR = 3.88, 95% CI 0.93–16.24, p = 0.064). The CD44 + /CD24 − phenotype was negatively correlated with postoperative DFS (HR = 1.67, 95% CI 1.35–2.07, p < 0.00001) and OS (combined HR = 1.52, 95% CI 1.21–1.91, p = 0.0004). Conclusion These results suggested expression of the CD44 + /CD24 − phenotype cannot be used as a reliable indicator of the tumor size, lymph node metastasis, and distant metastasis, however, it can be used be a potential therapeutic targets of DFS, OS in breast cancer patients.