Prognostic values of STAT3 and HIF-1α in esophageal squamous cell carcinoma

To investigate the expressions of signal transduction and activator of transcription 3 (STAT3) and hypoxia-inducible factor 1-alpha (HIF-1α) in esophageal squamous cell carcinoma (ESCC), and their potential roles in the pathology of ESCC.

Tumor tissues and clinical data of 202 ESCC patients treated in our hospital from January 2011 to June 2013 were collected. Expressions of STAT3 and HIF-1α in tumor tissues and normal esophageal tissues were detected by immunohistochemical S-P method. Correlation of STAT3 and HIF-1α with clinicopathological parameters and prognosis of ESCC were analyzed.

STAT3 was positively expressed in 82/202 ESCC tissues, with a positive expression rate of 40.59%, and HIF-1α was positively expressed in 142/202 ESCC tissues, with a positive expression rate of 70.30%. Both STAT3 and HIF-1α were highly expressed in ESCC tissues than those normal esophageal tissues, showing statistically significant differences (p<0.05). The expression of STAT3 was positively correlated with that of HIF-1α in ESCC tissues (r=0.401, p<0.05). Overall survival (OS) and disease-free survival (DFS) of ESCC patients with positive STAT3 and HIF-1α expression were markedly worse than those with negative expression (p<0.05). STAT3 and HIF-1α were related to the infiltration depth (T stage) of ESCC (p<0.05). Univariate and multivariate analyses revealed that the expression of STAT3 was associated with OS and DFS (p<0.05) and was an independent prognostic factor for ESCC.

High expressions of STAT3 and HIF-1α are closely related to ESCC. STAT3 is an independent prognostic risk factor for ESCC, and HIF-1α may be a poor prognostic survival factor for ESCC, both of which can be used as indicators to predict the prognosis of ESCC patients.