Expression of signal transducer and activator of transcription 3 in breast cancer and its clinical significance

Objective: The aim of this study was to investigate the expression of signal transducer and activator of transcription 3 (STAT3) in breast cancer tissue and normal breast tissue in breast cancer patients and whether it was correlated with clinical parameters. Materials and Methods: Seventy-six breast cancer patients were retrospectively analyzed in the patient database of our hospital. The expression of STAT3 in 30 normal breast tissues and 76 breast carcinoma tissues of breast cancer patients was determined using immunohistochemical staining assay. The clinical characteristics such as age, tumor diameter, clinical stage, pathology grade, and lymph node metastasis were recorded by two authors. The correlation of STAT3 expression and clinical parameters were analyzed by Chi-square test with Stata version 11.0 software. Results: The positive expression of STAT3 in normal breast tissues (23%) was significantly lower than that in breast carcinoma (66%) (P < 0.05). The expression of STAT3 in breast carcinoma was significantly associated with the clinical stage (P < 0.05), differentiation (P < 0.05), and lymphatic metastasis (P < 0.05). Conclusion: The positive expression rate of STAT3 was higher in breast cancer tissue compared to normal breast tissue, which was correlated with clinical stage, tumor differentiation, and lymph metastasis.