Background & objective: Transcriptional factor Sp1 is involved in many biological processes, such as cell proliferation, apoptosis, differentiation and transformation, and plays an important role in invasion and metastasis of tumors. However, the expression patterns of Sp1 in various tumors are different. This study was to investigate the correlations of Sp1 expression to metastasis, invasion, and prognosis of breast cancer.
Methods: The expression of Sp1 in 60 specimens of breast cancer and 12 specimens of adjacent breast tissue was detected by EnVision immunohistochemistry. Its correlation to clinicopathologic features of breast cancer was analyzed by Cox regression analysis.
Results: The positive rate of Sp1 was 71.67% in breast cancer tissues, and 33.33% in adjacent tissues. Sp1 staining in cancer tissue was positively correlated to TNM stage (r=0.349, P<0.05), tumor invasion (r=0.407, P<0.01), and lymph node metastasis (r=0.314, P<0.05). Univariate analysis indicated that the overall survival rate was significantly lower in Sp1-positive patients than in Sp1-negative patients (41.86% vs. 82.35%, P<0.05). Cox multivariate analysis showed that Sp1 expression, TNM stage, invasion and lymph node metastasis were independent prognostic factors of breast cancer.
Conclusions: Sp1 maybe participate in the invasion and metastasis of breast cancer, and is one of the valuable markers indicating poor prognosis of breast cancer. Sp1 detection, with consideration of tumor invasion and clinical stage, may increase the accuracy of predicting prognosis of patients with breast cancer.