Association between serum miRNA-218 expression and (A) lymph node metastasis, (B) tumor stage, (C) pathological type and (D) tumor size. Patients with lymph node metastasis, later stages and more invasive pathological type exhibited lower expression of miRNA-218 in the serum samples. The expression of miRNA-218 in the serum was not associated with the tumor size. miRNA-218, microRNA-218; FIGO, International Federation of Gynecology and Obstetrics.