Clinical significance of PEA3 in human breast cancer

Background. Recently, PEA3 has been reported to suppress HER-2/neu overexpression by promoter activity and thereby inhibit tumorigenesis of breast cancer both in vitro and in vivo. Methods. The expression of PEA3 and the clinicopathologic features of 89 patients with breast cancer were investigated. The expression of PEA3 was immunohistochemically detected in 42 (47.2%) of 89 patients. Results. The correlation between the expression of PEA3 and the clinicopathologic features were nil with regard to lymph node metastasis, hormone receptor, blood vessel invasion, and lymphatic vessel invasion. The disease-free survival rate was shorter for the PEA3-negative groups than for the PEA3-positive ones, but with no statistically significant difference. The overall survival rate after surgical resection in patients who were PEA3-positive vs PEA3-negative was 100% vs 87.2%, respectively, at 3 years and 89.8% vs 72.7%, respectively, at 6 years (P=.0472). Conclusions. The expression of PEA3 in breast cancer might therefore be a novel prognostic factor.