Dual high expression of STAT3 and cyclinD1 is associated with poor prognosis after curative resection of esophageal squamous cell carcinoma.

BACKGROUND Signal transducer of activator of transcription 3 (STAT3) and cyclinD1 are overexpressed in various human cancers, and their overexpression positively correlates to tumor progression and poor prognosis. However, the clinical significance of dual high expression of these two proteins in esophageal squamous cell carcinoma (ESCC) has yet to be determined. METHODS The expression of STAT3 and cyclinD1 was analyzed in tissue microarrays containing tumor and adjacent tissue samples from 82 patients who had undergone curative resection for histologically proven ESCC. Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the prognostic value of STAT3 and cyclinD1 expression. RESULTS We discovered that expressions of STAT3 and cyclinD1 in cancer tissues were significantly higher than that in adjacent tissues. High expression of STAT3 and cyclinD1 was associated with malignant behaviors. Moreover, the expression of STAT3 was positively associated with the expression of cyclinD1. High STAT3 or cyclinD1 expression alone was associated with lower overall survival (OS) rates. Furthermore, dual high expression of STAT3 and cyclinD1 expression predict even worse survival outcome in both univariate and multivariate analysis. CONCLUSION STAT3 and cyclinD1 correlate with more aggressive tumor behavior in ESCC. When STAT3 and cyclinD1 are considered together, they serve as effective prognostic markers in patients with surgically resected ESCC.