Activated STAT3 correlates with prognosis of non-small cell lung cancer and indicates new anticancer strategies

Aberrant activation of the signal transducer and activator of transcription 3 (STAT3) occurs in many human tumors. Many studies have provided compelling evidence for the critical role of aberrant STAT3 activity in malignant transformation and tumor progression. But few of them provided data on whether activated STAT3 overexpression correlated with patients' prognosis. Here, we define the relationship between phosphorylated STAT3 (pSTAT3) function and prognosis of non-small cell lung cancer (NSCLC). Immunohistochemical analyses were carried out on 82 surgically resected NSCLC tissues to evaluate the expression level of pSTAT3. The Kaplan-Meier method was used to calculate the survival rate, and the log-rank test was performed to compare the survival difference. Cox regression analysis was performed to identify prognostic risk factors. All statistic analyses were performed with SPSS11.5 statistical software. Differences were considered significant when the P value was < 0.05. In this study, we identified nuclear pSTAT3 expression in 59.76 % of tumors. pSTAT3 expression was correlated with differentiation degree of tumors (P < 0.05), lymph node metastasis status (P < 0.01), clinical stage of tumors (P < 0.01) and the prognosis of NSCLC patients after surgical resection (P < 0.05). pSTAT3 overexpression is an important factor related to prognosis of NSCLC patients and indicates new anticancer strategies.