Breast cancer is a common malignant neoplasm that is a leading cause of cancer death in women despite recent advances in treatment and research. The role of lymphangiogenesis in breast cancer development remains a source of controversy in current research.

The relationship between lymphatic microvessel density (LMVD) and the clinicopathological parameters of breast cancer can be effectively examined by meta-analysis of recent studies.

A total of 10 relevant studies consisting of 1,044 total patients were examined by electronic searches of PubMed and Embase databases. Weighted mean difference (WMD) and 95% confidence intervals (CI) were estimated and pooled according to standard methods. LMVD data was pooled by tumor size, lymphatic node metastases, and tumor hormone receptor status of estrogen receptors (ER) and progesterone receptors (PR).

A remarkable correlation between LMVD and lymph node metastases was observed in pooled analyses using a random-effects model (WMD: 2.72; 95%CI: 2.27, 3.16; P=0.000). LMVD and tumor size showed a pooled WMD value of 0.00 (95%CI: -0.49, 0.50; P=0.009), indicating no significant correlation between LMVD and tumor size. LMVD and either ER or PR status showed pooled WMD values of 0.24 (95%CI: -0.30, 0.79; P=0.004) and -0.12 (95%CI: -0.81, 0.56, P=0.301), respectively, also indicating no significant correlation between LMVD and ER or PR status.

A close relationship was observed between LMVD and lymph node metastases, though no correlation between LMVD and other important clinicopathological parameters was apparent. The current meta-analysis suggests that LMVD may be associated with increased metastatic activity in breast cancer, though the full role of lymphangiogenesis in breast cancer remains uncertain.