MMP2 and metastatic malignant neoplasm in the lymph nodes: We observed significant publication bias in the analysis of the association of MMP2 overexpression with survival (P < 0.05), ER status (P = 0.003), and lymph node metastasis (P = 0.003), as well as MMP9 overexpression with lymph node status (P = 0.045) and TNM stage (P = 0.042).