[Expression and clinical significance of calcium-binding protein S100A9 in breast cancer].

AIM: To investigate the expression and clinical significance of calcium-binding protein S100A9 in the patients of breast cancer. METHODS: The serum S100A9 level from 39 cases of preoperative breast cancer, 15 postoperative patients, and 10 healthy women was detected by ELISA. Immunohistochemistry was used to detect the S100A9 expression in 12 specimens of breast cancer tissues. RESULTS: The serum S100A9 level was significantly higher in the preoperative breast cancer patients than that in the healthy women (P<0.01) and the postoperative breast cancer patients(P<0.01). The serum S100A9 level of the breast cancer patients with lymph node metastasis was significantly higher than those without lymph node metastasis (P<0.01). S100A9 level in the serum was related to patient age, tumour size, histological grade, and pathological type (P<0.01). The expression of S100A9 protein in breast cancer tissues was significantly higher than that in paracancerous benign breast tissues. CONCLUSION: The expression of S100A9 significantly increases in the serum and tissues of patients with breast cancer, which indicates that S100A9 may function as a marker of diagnosis and treatment effect in breast cancer.